ContinuousWave
Whaler
Moderated Discussion Areas
ContinuousWave: Whaler Performance
Propeller: OUTRAGE 18 with 150-HP
search | FAQ |
profile | register | author help
|
|
ContinuousWave Whaler Moderated Discussion Areas
ContinuousWave: Whaler Performance
Propeller: OUTRAGE 18 with 150-HP
|
| Author | Topic: Propeller: OUTRAGE 18 with 150-HP |
| kamie |
posted 05-07-2004 04:14 PM ET (US)  
Based on running around last weekend I am thinking the prop on the 150 needs to be changed. I checked the reference section and using Jim's handy caculator I should be running an prop pitch of 18. (5600 RPM, ratio 2:1,slip 8%, speed 44mph) Plugging the numbers into Mercury's prop selector, it suggests an pitch of 25. Looks like the general feeling from previous posts is pitch in the 18~19 range. I am taking friends out on Sunday with a GPS and a notebook. What tests should I run on the current prop? I am also going to see if I can figure out what pitch is on their now, I looked before but didn't see any markings at all. As a side note, I am sure the engine is mounted too far down since it's in the last holes, but I won't be able to tell until I pull the boat later this month. Thanks for the help. |
| Tom W Clark |
posted 05-07-2004 04:29 PM ET (US)
Kamie, Boston Whaler's recommendation has always been to mount the motor on an Outrage 18 one hole up (3/4" higher than where yours is now). While the pitch for your boat is dependent on many factors, I can say that the vast majority of Outrage 18s with 150 hp motors run best with props that have a 19" pitch, or something close to it. This was the case with my 1983 Outrage 18 which had an OMC SST II of 19" pitch. I tried a 21" SST II at one point but that proved to be too much pitch even when the boat was light on fuel and I was the only one onboard. Top speed AND acceleration suffered. I went back to the 19" pitch prop. |
| LHG |
posted 05-07-2004 05:57 PM ET (US)
For a 2.0 liter Merc 150, I would use a 19" Pitch Laser II prop, installed in third set of holes (1 1/2" elevation). That should give you speeds up to 48 mph. Something is wrong with your prop calculator figures from Mercury. |
| Peter |
posted 05-07-2004 06:03 PM ET (US)
Powered by a 150 HP outboard with a gear ratio of around 1.86:1, a 19P prop is usually the best all around size for the 18 Outrage. I used a 21P OMC Raker on the 150 Johnson that pushed my 18 Outrage. It worked out fine. Acceleration was quite good and was probably due to the vent holes. I can't imagine what the acceleration would have been like with a 19 P as you had to hang on when the throttle was "punched" with the Raker. It worked best when the engine was mounted two holes up. I have never been able to get the Mercury prop selector to provide a good answer. It always seems to recommend a prop that has too much pitch. |
| kamie |
posted 05-07-2004 08:52 PM ET (US)
Thanks for the suggestions. Larry, your suggesting raising 2 holes rather than the 1 hole Tom suggested? |
| LHG |
posted 05-10-2004 02:28 PM ET (US)
The middle set of holes, giving 1 1/2" engine elevation, should only be used with a Mercury performance series prop. All of the performance series have vent holes, so are easy to identify. Before you decide on engine mounting height you will have to determine the prop you want to use. I just realized you have a Tee-top & bottom paint, and this will take about 3 mph off possible top end, so speeds I indicated above might be high. You are probaly right on the line where a Laser II prop makes sense, as opposed to a 4 bladed Vensura/Offshore. Both will give much needed lift on this hull and improve the ride and efficiency. The 4 bladed Vesura/Offshore prop might be worth considering as an alternative to a Laser II, since high speed will not be a consideration, and can be purchased in 17" pitch also. I think that is the prop I would buy for your situation. You will have to determine which pitch is best |
| kamie |
posted 05-10-2004 05:04 PM ET (US)
Thanks Larry, As for the t-top, it's staying for at least this year. I am not too worried about loosing 3 mph off a max of 48 +-. Somehow I don't envision a jaws squeal with me playing Capt. Quinn. If that happened I would definitely need a bigger boat. I was looking at the Vensura since my goal is offshore but that may be a bit far away. Most of my boating will be in the river, with a couple of runs per year in the Chesapeake Bay. For those conditions would the Laser II make a better choice or would you still consider the Vensura? |
| gvisko |
posted 05-10-2004 06:48 PM ET (US)
I have a 14.25x17 ss on my 18' outrage with 150 johnson I also have a t-top and bottom paint . I get 46mph wot I took off the 19 the 17 is the way to go.
|
| Joe Kriz |
posted 05-10-2004 07:06 PM ET (US)
kamie, When I bought my Outrage the Evinrude 150 was mounted all the way down. I also received 3 props with the boat.. All OMC Originally the eninge had the 15 pitch but I knew it could handle more so I put on the 17 pitch.. I run right around 5300 RPM with the 17 pitch, it has a great hole shot, and cruises very nicely around 3500 RPM at about 35 mph. |
| Mumbo Jumbo |
posted 05-10-2004 08:46 PM ET (US)
I have a 1989 Outrage powered with a 2000 150hp two stroke Yamaha. I tried the 19" stainless Yamaha prop but it had too much top end so I switched to the 17" stainless prop. It gave much better performance in steep following seas. I really don't care how fast the Outrage goes as long as it handles properly in difficult sea conditions. If you find yourself in rough sea conditions, the 17" is a good choice. |
| Sal DiMercurio |
posted 05-11-2004 12:35 AM ET (US)
Joe, you wont get 35 mph at 3,500 rpms with a 17p prop. The closest pitch to match rpms to speed is a 21p. At 3,500 rpms & a 17p prop your getting around 26 kts. = 29.9 mph. Sal |
| Mumbo Jumbo |
posted 05-11-2004 07:19 PM ET (US)
Sal- I don't know what a 150 Johnson/Evinrude/ Bomb will do, but i get at least 40mph with the Yamaha 17" stainless prop on my 150 Yamaha two stroke. |
| Joe Kriz |
posted 05-11-2004 08:04 PM ET (US)
Sal, I was wondering when someone might see my Typo... |
| Sal DiMercurio |
posted 05-11-2004 08:57 PM ET (US)
Joe, when running a 21p prop & acceptable slip, you can darn near tell exactly how fast your running by looking at your tach. For instance, at 3,500 rpms & a 21p you can bet your real close to 35 mph. It's really pretty close from 3,500 rpms on up. Mumbo, you should be getting closer to 45 - 48 mph maybe even a bit more with the 19p, I see no reason why you shouldn't get 45 mph with the 17p at 5600 rpms. In rougher water [ ocean ] I prefer running 2" less pitch then I run on the river. On the Sacramento river I run a 14.25 x 21 with the engine up on the 3rd set of holes, but when I bring the boat to the ocean for the summer & salmon & tuna fishing, I drop the engine down 1 set of holes & go to a 14.25 x 19p for better bite in sloppy water. Sal |
| LHG |
posted 05-11-2004 09:30 PM ET (US)
I have found Sal's comments on the 21" pitch props to be correct when running though a 1.87 gearcase. Gear ratios can make a difference here. Running a pair of Mercury 21" pitch 4 bladed Revolution 4 props on my Outrage 25, I have found 4000RPM to be 41mph and 5800 RPM to be 61 mph. The 4 blades have a slighly bigger bite (or higher efficiency) than a same pitch 3 blade. |
| kamie |
posted 05-16-2004 10:32 AM ET (US)
Took her out yesterday and ran around the the Occoquan Bay for a while. It was pretty choppy so I didn't open her all the way up but did consistently hit 30 mph at 4000 RPM's. Assuming Jim's prop caclulator works lower than WOT, the prop on there now is a 17p. I was strongly considering Larry's suggestion of the Vensura in a 17p. Based on that should I raise the engine 2 holes or 1. The first place this will get run is in the Chesapeake Bay for the teaparty. I have one more weekend in Occoquan Bay / River before I pull her and change the prop and raise the engine. Any other timings I should run now that I can pilot and look at the GPS at the same time while I have the current setup? |
| kamie |
posted 05-19-2004 01:36 PM ET (US)
Well, I called the local Mercury Prop shop today and his suggestion to use either the Black Max in aluminum or the Vengeance if I wanted to move to SS. He advised against going with the performance props, for pitch he was firm on going with the 17p. What advantages would I gain over the Vengance by stepping up to the Vensura? Obviously 4 blades holds better than 3 but there must be something else. |
| rtk |
posted 05-19-2004 05:28 PM ET (US)
The Mercury web site has descriptions/applications of their props that may be helpful to you. http://www.mercurymarine.com/props I do have a 17 pitch four blade Vensura that I will be selling. I purchased it new and it has about five hours on it. It is just not the right prop for the boat. (1997 21 foot Outrage) If you want to try it out I can send it to you- if you like it we can work out the details. Email me if you are interested. I also have a used LaserII 19 pitch if you have an interest in trying out a LaserII. Rich |
| kamie |
posted 05-19-2004 11:42 PM ET (US)
Rich, I have read and re-read the mercury prop page a dozen times. Based on some older threads (finally feed the search engine the right words) I have a better understanding of why some of the suggestions were made. Does raising the engine help lower the bow? With two people standing/sitting at the helm (~400lbs) the bow shoots very high and the boat never really levels off once on plane but maintains more of a bow up attitude. I am not too worried she would flip, but I don't think I need assistance with bow lift. Sitting one person forward is not really an option since the cooler seat doesn't not provide enough back support for someone that needs it. |
| jimh |
posted 05-20-2004 08:22 AM ET (US)
Raising the engine reduces the amount of drag by reducing the volume of the engine lower unit being dragged through the water. Less drag will mean more speed. Raising the engine causes the propeller to operate closer to the surface. This may affect the propeller's ability to maintain thrust without ventilating. The tendency for the bow to rise when coming onto hydroplane or while running on hydroplane may be affected by the engine height, but I don't know if there is a simple predictor. |
| LHG |
posted 05-20-2004 07:40 PM ET (US)
Kamie - One of those two props that rtk has are going to work perfectly for you. I'd ignore your Mercury prop shop guy, and try the 17" Offshore/Vensura first. If it over-revs on light loading, step up to the 19 Laser II. For a boat that will run mid-40's, a Vengeance elephant-eared SS prop would not be best, since it has no lift, and won't hold with engine mounting in 3rd set of holes. With no bottom paint and no tee top, your rig should run close to 50, necessitating a 19" prop. With a 150HP engine on an 18 Outrage, an aluminum prop should never be run, regardless of engine brand |
| Plotman |
posted 05-20-2004 08:20 PM ET (US)
I used to have an 18 with a Merc 150. I ran a standard aluminum 19" prop. Trimmed way out, I could hit 47 when lightly loaded. I would strongly suggest moving the engine up at least one hole and assesing what you have now. If you need to go higher later you can. I posted how I raised the engine on my old 22 using just the trailer and 2 tie down straps in about 15 minutes. David |
| kamie |
posted 05-20-2004 08:55 PM ET (US)
Thanks Larry, I have already sent and email to Rich to work out the details. David, I am planning on raising the engine one hole probably this weekend before the tea party next weekend. I have the straps and a friend already lined up to help. Will probably do it on sunday so my friend can get a ride in the boat before I make him help me out. :-) |
| kamie |
posted 05-21-2004 01:11 PM ET (US)
Rich sent off the prop for me to try so I should have it before the Tea Party. Two remaining questions. 1. I assume if I put the Vensura on I should raise the engine 2 holes to start? 2. What's the best way to get the old prop off? My quess is the previous owner hasn't had the prop off in awhile. |
| LHG |
posted 05-21-2004 01:43 PM ET (US)
Mercury performance series props generally need to be run 1 to 1-1/2" high (2nd or 3rd bolt hole sets). Running them fully submerged increases the effective pitch by 2" and does not allow them to perform as designed. |
| ConB |
posted 05-23-2004 05:26 PM ET (US)
LHG- On my just purchased Outrage 18 I have a 150 Johnson with a 14 1/4 x 21 aluminum prop. Engine is all the way down on transom. What is your thinking on not using an aluminum prop on any Outrage 18 engine? Thank you, Con |
| kamie |
posted 06-12-2004 05:04 PM ET (US)
With the engine raised one hole and the new vensura on it seems I went from bad to worse. idle -800 rpm 3.5mph I think the next step to put the old aluminum prop back on and see what sort of speed I get out of that now that the engine is raised one hole. That way I will have something to compare things too. I also noticed that when she comes up on plane the stern drops fairly deep and there is incredable bow rise. I did manage to open her up and she hit 5600 rpm but I dont' have a speed on her. She was riding nice at that a point ~5200 rpm, where bow came down and she skipped across the water. I am guessing here but I think my issues in the bay had more to do with the prop slipping than the engine being too high, although the wave size makes that sort of a toss up. |
| rtk |
posted 06-12-2004 06:21 PM ET (US)
Sorry to hear that Kamie. Even with that prop on my 21' Outrage and the engine height too high, she would plane at a little over 3500 RPMs. Looks like she is really struggling to get up on plane. Did you have the engine trimmed all the way down when starting out? If it is trimmed up too much when trying to get on plane the bow will come up alot. Hope you get it worked out. Rich |
| jimh |
posted 06-13-2004 07:51 AM ET (US)
Kamie--please give us the dimensions of the propeller you were testing. |
| jimh |
posted 06-13-2004 07:53 AM ET (US)
Kamie--Please give us the engine lower unit gear ratio. |
| rtk |
posted 06-13-2004 08:39 AM ET (US)
Jim, the propeller Kamie is testing is a 14.5 inch diameter by 17 pitch stainless four blade Vensura Offshore Mercury propeller. It is a brand new propeller with only a couple of hours on it. Rich |
| kamie |
posted 06-13-2004 01:43 PM ET (US)
Jim, gear ratio is 2:1 |
| LHG |
posted 06-14-2004 06:29 PM ET (US)
Sounds like the prop is not installed correctly. There is no way you'd get 22 mph at 5000RPM. Is the plastic sleeve inserted properly? You're lucky you didn't lose the prop. Using that identical prop, a friend gets 42MPH out of a Yamaha 150, on the heavier 19 Outrage II model, engine up 2 holes . Boat should run 46-48 mph. With prop CORRECTLY installed, if engine will turn over 5600, move up to a 19" Laser II. |
| kamie |
posted 06-18-2004 04:13 PM ET (US)
Larry, The sleeve is inserted same as it was when rich sent me the prop. I have purchased a new flow-torq II hub kit that fits the engine and am going to reinstall the prop. According to the prop box the kit that it came with and the kit i purchased are the same. I did notice that the plastic sleeve that is in there is jamed in tight. I suspect that it is supposed to be that way, just to be sure I will remove it and replace it with the new sleeve I just got. |
| LHG |
posted 06-18-2004 04:52 PM ET (US)
The plastic drive sleeve should slide in and out freely. This sounds like your problem. It's probably "spun". Always carry a spare, as they are owner replaceable when needed. |
| kamie |
posted 06-18-2004 05:54 PM ET (US)
Thanks Larry, I will get the one out that is in there and replace it with the new on from the kit. Then i'll grab a spare next week. Hopefully I should have fresh numbers tomorrow if the weather holds out. |
| kamie |
posted 06-18-2004 08:02 PM ET (US)
I wanted to double check. The plastic sleve slides in but doesn't go fully into the hub. There is about 1/2 inch sticking out? Just wanted to see if that was normal? kamie.homeip.net/evenstar/html/the_to_do_list.html |
| Peter |
posted 06-18-2004 09:55 PM ET (US)
On the Mirage prop I have, the Delrin sleeve is almost flush with back side of the hub. The sleeve should just drop in. Make sure you line up the flat sides of the sleeve with the flat sides on the inside of the hub. |
| rtk |
posted 06-18-2004 11:20 PM ET (US)
That is interesting. I thought it was odd that the dealer used a little persuasion to seat the hub. When I removed and and installed my LaserII last year the hub did slide in and out easily. Perhaps that explains my problems with the prop- not ventilating but slipping. I was getting 45 MPH at wide open throttle with my boat though with the engine mounted on the middle hole. I would only slip when it was a bit choppy, not when it was calm. The second prop I put on the boat did the same thing under the same conditions so I just assumed that the engine was one hole too high. Hope the new hub solves the mystery of the slipping prop. If it is an incorrect or bad hub I certainly apologize Kamie, I had no idea. Rich |
| kamie |
posted 06-18-2004 11:35 PM ET (US)
I took a look at the old vs new sleeves and the old one drops in farther but does not slide in all the way on it's own. I think i'll stick to the new hub kit,with all new parts and see what happens. |
| kamie |
posted 06-19-2004 04:27 PM ET (US)
well, no luck. engine spinning 4000rpm and boat moving at a blazing 10mph. tossing in the towel and calling the local prop shop on Monday. As she is sitting now, I could almost row her faster :) |
| LHG |
posted 06-21-2004 02:11 PM ET (US)
Something is wrong with that prop. The torque sleeve goes all the way in, and easily. Only other solution is that your drive shaft splines are stripped at the engine. |
| Peter |
posted 06-21-2004 03:59 PM ET (US)
I'm wondering if the tachometer is working right. |
| kamie |
posted 06-21-2004 06:17 PM ET (US)
Larry, If the drive shaft splines were stripped at the engine, I would expect no movement at all? The boat moves along at idle and low rpm's just fine, it's when you apply power and torq to the prop that things go all wrong. Also the boat was fine with the old prop Peter, the tach is fine. You can hear the engine rev way up and the boat isn't moving. Stopping out at the local prop shop in the morning on the way to the office. |
| LHG |
posted 06-21-2004 06:54 PM ET (US)
Then something is wrong between the crankshaft and the prop blades! |
| rtk |
posted 06-21-2004 08:30 PM ET (US)
Kamie, at www.mercurymarine.com/props they have a great illustration of how the components of the Flo-Torq II hub system should be assembled. It is at the bottom of the web page after the individual prop listings and descriptions. The aft adapter (brass) accepts the splines on the shaft. The Delrin sleeve accepts the aft adapter. It is the Delrin sleeve that will "break away" (by design). If you remove the sleeve I would think it would be easy to tell if it is damaged. If it is a new sleeve will cure the slip. The Delrin sleeve must be inserted into the prop so the section of the sleeve that accepts the aft adapter is inserted first. By your pictures it looks like the sleeve is inserted properly. I picked up a new hub kit for my LaserII prop yesterday. The sleeve slid in freely but not all the way in. It will take a light force to seat the sleeve all the way in. It needs to go in another 1/4 inch or so. I sure hope that the prop or a hub component is the problem and it is not a mechanical problem. Rich |
| kamie |
posted 06-24-2004 05:49 PM ET (US)
Well, I though I would bring folks up to speed with where I am on the prop situation. I stopped by the local Merc prop shop yesterday and picked up a Black Max 21p and had the boat out today. It is too high in pitch as I suspected (only turning 5000 RPM at WOT) but in every other way exceeded my expectations. The boat has not run this good since I got her. With a touch of the throttle she was flying up on plane, minimum of bow rise and once trimmed out she just flew over the water. With just me in the boat and a shade over 3/4 of a tank of gass I was at 40+ mph at 5000 rmp's. So tomorrow I return the Black Max 21p and drop down to the 19p which hopefully will dial me where I need to be for the RPM's. Hopefully I can get some good rpm to mph numbers this weekend although The boat won't be so lightly loaded. Thanks for everyone that helped. |
| Peter |
posted 06-29-2004 07:43 PM ET (US)
I had a stubborn sleeve on a Mirage prop that would not drop into the hub, much like what Kamie's picture shows with about 1/2 inch sticking out. The trick to getting it to drop in nearly all the way is to put the plastic sleeve in the freezer for an hour before inserting it into the propeller hub. |
| rtk |
posted 06-30-2004 08:51 AM ET (US)
Glad too see you have the boat running well. Enjoy! Rich |
| kamie |
posted 06-30-2004 11:10 AM ET (US)
Thanks Rich, I didn't get good numbers last weekend because it was way to choppy so hopefully I can sneak out of work tomorrow and get some with just me in the boat. With about 300 pounds of people this weekend she was a bit sluggish getting on plane but I really need to test her out with just me. If I'm not happy with how she is working it's back to the prop guys. |
| kamie |
posted 07-05-2004 11:01 AM ET (US)
I got some new numbers this morning. With just me in the boat and totally flat water she was turing 5400 RPM's at WOT and showing 40.3 MPH on the GPS. This was with the Black Max 19p and only me in the boat. She pretty much popped up on plane and crused pretty good at around 3000 to 3200 RPM trimmed all the way out. |
| LHG |
posted 07-06-2004 04:49 PM ET (US)
I think the tee top and bottom paint are killing your speed, unless the engine needs work. I now have the same the 2.0 liter Merc 150, 1988 model, and it is a hot engine for its small size from what I can tell. On the 1971 Outrage 21, no bottom paint, and engine all the way down, it turns up a 21-inch pitch Laser II to 5400 with light fuel and two aboard. Speed estimated at 46-48 MPH. Buckda's 18 Outrage, also with same engine, runs about 45-MPH, but couldn't keep up with me! |
| Buckda |
posted 07-06-2004 05:38 PM ET (US)
In fairness, I was not fully trimmed....but I digress. My standard SS prop will shortly be relegated to "standby" status in favor of a 19 Inch Pitch Merc Laser II like LHG has on his 21. I can push 6,000 RPMs with the current prop but it has trouble and "ventilates"...I am convinced that the Laser II prop will get me an extra 3-5 MPH. LHG - I had 55 Gallons of Fuel, compared to your 12...come on now...let's do this for real later this summer on a smooth lake! The 45 MPH was measured going against current and into the wind too...I think I could have you equally propped and equally weighted :) Dave |
| kamie |
posted 07-06-2004 08:41 PM ET (US)
With just me in the boat she runs well. No speed deamon but that could be the bottom paint and t-top. When I add some friends the performance really tanks, hole shot and speed suffer. She struggles to get on plane. The prop guys are saying that the prop is fine, get the engine tuned and of course the engine folks are telling me there isn't anything wrong with the engine, it was tuned in April and drop down to a 17p prop where it was before I started this and she should work fine. At this point I am looking to get back to the ok performance I had before so at least I can go out and enjoy the boat. |
| kamie |
posted 07-07-2004 01:52 PM ET (US)
If one was going to look at the engine for the problems what would be some likely issues to have checked? The mechanics I took the engine too earlier tried to tell me the hull was waterlogged it is a boston whaler, and put twins on the back if I wanted her to move. So, not going to see them again, I have an appointment with another shop on Friday but want to come prepared with more than my credit card. Something is wrong here if the engine won't push the boat,me and at least one or two of my closest friends. |
| David Jenkins |
posted 07-07-2004 04:31 PM ET (US)
LHG, is your engine mounted all the way down on purpose, or just because you have not gotten around to moving it up? I have the smaller version of your boat, the 1974 OUTRAGE 19 with a Suzuki DF140 mounted three holes up. I think it may be mounted too high as it does "ventilate" on sharp turns. The bottom mounting bolts go through the transom and have retaining nuts so to move it down I would either have to fill those holes and use lag bolts or else install a jackplate (which I own and wanted to use but which my mechanic refused to install). (I am in a hot, parked car (saving fuel), passing time during a home inspection, tapping into someone's wireless Internet connection. I think I may need to start the car and get the AC running!) |
| Dauntless18 |
posted 07-07-2004 07:28 PM ET (US)
Kamie: Though this thread seems to have meandered a bit, I have to express my sympathy. How frustrating. It's like a computer I had (hardware guy says its the software, software guy says its the hardware, etc.). I am a neophyte to boat ownership, but have a few, potentially ill-formed, thoughts. If the performance is OK with just you, but drops off if you put a couple of friends in the boat, then this should rule out the "waterlogged" hull answer, right? Two peoples' weight wouldn't make a difference if that were the case. Also, a 150 engine on an 18ft Outrage should easily handle a 19p prop, right? My 18 Dauntless with 135 Opti handles a 19p Mirage Plus (that is, when I don't mess things up by leaving her trimmed out on hole-shot - did that once and couldn't figure out why the bow was so high). Now that I always start trimmed in and a quick throttle for the hole-shot, she pops up on a plane pretty quick (and that is with a bow-rise ready Dauntless). Are you sure the prop isn't slipping on the shaft or venting (with the extra weight of friends pushing it just over the edge of holding in either case?) It has been a pleasure reading your posts on your project and I hope you can resolve this quickly. David |
| jimh |
posted 07-07-2004 08:27 PM ET (US)
To settle doubts about the motor, find a shop with a propeller shaft dynamometer and see if it turns out 150-HP or not. |
| kamie |
posted 07-07-2004 11:58 PM ET (US)
David, when your software guy tells you it's hardware and the hardware guy tells you it's the software, call me. computers I can deal with it, cranky outboard engines are beyond me. I have to thank Scott and Rich at Whalertowne who spent a lot of time on the phone today going over all the things I have tried and the results I have had. I needed an independant third party to confirm that something was indeed wrong or I was totally going nuts. We concluded the former was probably the case although the latter is still open. I am taking it in on friday to another shop where I will go over with the mechanic all the steps todate and rule out stupid operator error like installing the hub kit wrong and that sort of thing. Not sure if they have a dynamometer but I will check, assuming we eliminated all the basic stuff. I just plugged the numbers into the prop caculator that I got with just me in the boat and I come up with a slip of 17% at WOT with only me. I'll keep folks posted on the progress |
| Plotman |
posted 07-08-2004 08:59 AM ET (US)
If you can't get a shop with a prop dyno, at least make sure the compression in the engine is OK if you haven't done so already. If that checks out, it might be worth tearing down and rebuilding the carbs. I had to do this on one of my engines this spring - wow, what a difference it made. The engine idled fine and would run up to about 5400rpm. If I hadn't had its twin on the transom that was clearly giving beter performance (would run up to 6000 rpm, I might not have realized that some "oomph" was missing from that engine. I tore down and cleaned the carbs and did indeed find one of the high speed jets plugged. After I put it back on, the difference in performance was as clear as night and day. David |
| kamie |
posted 07-08-2004 10:46 AM ET (US)
Any idea what the cost of rebuilding the carbs would be to have a mechanic do it? I did notice that she is back to starting hard and running rough at idle. Smooths out once you go over 1200 rpm's I was going to have them do a compression test, even if the problem seemed to be a stupid user trick just to have one in hand for future reference. |
| Plotman |
posted 07-08-2004 02:14 PM ET (US)
I've now done it myself on 3 engines, but never paid anyone to do it - my guess is 3-4 hours of labor for the 3 carbs in a 150. The first time I needed it done the shop was booked longer than I wanted to wait, so I jumped in and did it myself. Was actually much easier than I thought it would be. Before going down this road, I'd suggest trying Bigshot's trick of running a can of techron mixed with a gallon of gas through the engine, letting it sit overnight with the gas/techron mixture in the carbs, then running the engine hard on clean gas the next day. This has a decent chance of working if your jets are cudded up, but not completely blocked. If one or more is blocked, the techron can't get through to do its thing. I'd also check the plugs - actually I'd just change them if that hasn't been done recently. A new set of plugs should be under $20. Still do the compression test first. You can buy a tester at an auto-parts store for $25, and do the test youself in 15 minutes. David |
| LHG |
posted 07-08-2004 04:01 PM ET (US)
David, the Merc 150 engine on this boat was very poorly and improperly installed on the boat. I will be changing it and raising it up one bolt hole at least, maybe two. Dave B, I'm running the 21" Laser II, which is probably what you should be running also. You can give mine a try if you like. For this 2.0 liter engine, with 2:1 gear ratio, Mercury says a 21" prop is for load range of 1600-2600 lb, with speeds between 46-52 MPH. This engine was Mercury's original entry into the V-6 category in 1976, and introduced the now widely used 60 degree vee. It originally came out as a 175HP, and was also the basis for the 135HP model. Somewhere around 1992, when OMC brought out it's version of the 60 degree vee 150, but with 2.6 liters, (which the Yamaha 150 also has), Mercury put the 150 on the 2.5 liter block used for the 200, just to make sure thei0r 150's didn't get out run by the large displacement OMC 150. |
| panther |
posted 07-08-2004 05:36 PM ET (US)
Generally speaking, when running a stainless steel prop. the cavitation plate on the motor should be about an inch above the lowest point of the transom. With performance props. one may go even higher. |
| kamie |
posted 07-09-2004 05:08 PM ET (US)
The boat is at the new mechanics. The current plan is to do the compression test and see where that gets us. We talked about the water in the hull deal and while he wants to do the moisture meter route should the compression test no show anything I told him it wouldn't suprise if there was some water, but enough to weight down the boat so a 150hp couldn't push the boat, I doubt it. I will keep folks posted on what I hear. |
| kamie |
posted 07-10-2004 06:12 PM ET (US)
I spoke to the mechanic today and here are the results Compression test: the low cylinder is at 100psi, there are 3 at 105 psi and the last 2 are at 110 psi Moisture: The moisture meter pegged at 30% for anything below the water line including the transom,near the rubrail he was getting a reading of 15% My Plans: First is to drop the prop back to a 17p for the rest of the season. Then while she is on the trailer I am considering drilling a few holes to see what comes poring out. Opening the deck plates to remove all the water in the bilge. lastly before I put her back in the water, take a drive toward Baltimore and put her on a scale. Beyond that: Open to suggestions? Hmm guess future threads need to go into the repairs section. |
| kamie |
posted 08-29-2004 05:03 PM ET (US)
I still have the 19p on the boat and had her out yesterday. She was turning 5200 at WOT so I am definatly going to drop down to the 17p. I didn't get a speed on her because the GPS decided I was going too fast and cut out. Engine range is 5000 - 5600 so I should be right about 5600 with the 17p. Test was run in flat water with 1/2 tank of gas and myself. The prop is a standard black max. |
| kamie |
posted 09-26-2004 09:29 PM ET (US)
I have still been playing with the prop but think I am a lot closer than I was before so I thought I would post an update. Got a good deal on a 19P Laser II. Running her today in flat water she was doing 5200 at WOT with myself and 3/4 tank of gas. She would hit 5100 ~ 5200 with 3 of us on the boat, 5200 with just me in the boat. Top speed was 41 mph on the GPS. I think that this is the prop I am going to stick with. Before I put her into the water next season I may raise the engine up one more bolt hole as she is only one hole up at this point. Thanks for everyone suggestions |
| jimh |
posted 09-27-2004 08:12 AM ET (US)
Kamie--Do you mention anywhere in this article what kind of motor you have? |
| kgregg |
posted 09-27-2004 01:15 PM ET (US)
JimH- Kamie has late 80s Merc 150 (I saw it yesterday.) Kevin |
| kamie |
posted 09-27-2004 08:01 PM ET (US)
Jimh, I have the same 2.0 Liter V6 150hp Merc that Larry has. The difference is mine is a 1995. The engine is raised 1 hole or the cavitation plate is 3/4 of an inch above the keel. If I understand Larry's comments Also looking for suggestions on the vent plugs. I believe that there are large vent plugs on the prop now. |
| LHG |
posted 09-27-2004 08:51 PM ET (US)
Kamie - In looking at your figures, and I think because of your tee top, you may be needing a 17" prop if she will only run 43 mph or less. I say this because of my considerable experience running Merc Laser II props, which are no longer considered Mercury's 1st tier LARGE gearcase props, except for certain circumstances, mainly 135-175 HP V-6 engines, pushing boats between 15-18 feet. I have discovered that Laser II's "turn on" above 4800 RPM, and really give their exceptional speed performance between 5000 and 6000. You need to get into that RPM range to make these props stand out, and in that range they are hard to beat. They will however, give good bow lift and a softer ride throughout the RPM range. But you are evidently not able to get into the performance range of this prop, and they don't make them below 19" pitch, also indicating these are props that perform best above 45 mph, and really best above 50. From everything I have read and experienced, you would be best with either the 17" Offshore/Vensura 4 blade, or the 17" Rev 4 if top speed is important. One of these is soon to appear on my Merc 2.0 liter 150 in 19" pitch version. The Vensura is a fabulous prop from what I have experienced, with great intermediate running properties and tremendous hull lift, it's only drawback being flat out top speed. Most of Mercs other props, such as Tempest Plus, Trophy Plus, Laser II, Mirage Plus, Rev 4, will be faster wide open. That's why the Rev 4 was designed, giving even better 4 blade offshore holding and flat out top end. Unfortunately, they are also Merc's most expensive prop, costing an additional $50 over the others (about $450). As a starting and general recommendation, Mercury recommends the use of the medium size vent plug for all outboard uses. I almost hate to say this, but running at 41 mph, if you don't want to go for a 4 blade SS, you will be better off with a tamer and lower cost 17" SS Vengeance prop at those speeds. A 17" Mich Wheel Rapture would also work for you. You should also note that although a 2" decrease in pitch change means an increase of 400 RPM, with a four blade, RPM will only increase about 200 RPM. In effect, they have about an additional 1" of effective pitch over same pitch 3 blade. |
| kamie |
posted 09-27-2004 10:33 PM ET (US)
Thanks Larry, I will try to pick up a Vensura in a 17p so I can try it out. I was leaning toward the Vensura before I picked up the Laser, I just happen to get a good deal on the Laser so I though I would give it a shot and see how it worked. Next time I am out I will try to MPH readings for the entire RPM range so I can compare the two props. I must say that the boat rides so much better than she has since I first got her. The SS prop makes a world of difference in how she rides and how she handles. What do I loose on either prop by leaving the engine mounted only one hole up? |
| kamie |
posted 10-03-2004 06:10 PM ET (US)
I managed to do a couple of runs today. The water was basically flat but there was a 10mph breeze which I could feel as the t-top would catch it. Prop: Laser II 19 pitch RPM MPH 3400 25 Boat had 1/2 tank of gas and me so fairly lightly loaded. I did manage to pickup a Vensura prop in 17 pitch so when I get that I will swap the props and do some testing with the new one. |
| LHG |
posted 10-04-2004 05:00 PM ET (US)
Mercury's prop charts show a 19" Laser II on your 150 running 41-48 MPH speed range. So you are at the bottom of it's capabilities. The Tee Top is killing you. The Vensura will probably not do much for top end, (unless you get rid of the tee top), but will give you better overall performance and acceleration, ride (due to increased hull lift) and higher RPM range. You will like it much better. |
| kamie |
posted 10-04-2004 06:27 PM ET (US)
Thanks Larry, I just picked up a 17p Vensura so hopefully I will have it by next weekend and can post some numbers. My only other question would be raising the engine up one more hole. I am still only 1 hole up, would it make a lot of difference in how the prop's perform? |
| |
Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.