Moderated Discussion Areas
ContinuousWave: Whaler Performance
1987 Evinrude question
|Author||Topic: 1987 Evinrude question|
posted 02-27-2002 08:50 AM ET (US)
Situation: 1987 Evinrude 150hp VRO on 1987 OR18. The motor usually starts and runs wonderfully, but last weekend we launched, started the engine for warm-up, stowed the gear. When we push the trottle to go up on plane, the engine revs up to about 1500 rpm and seems to bog down. Back off and it idles ok. I could shift into neutral and rev up to 4k w/o problems. Finally, after about 20 minutes of this, the engine coughed out a little smoke and then operated flawlessly for the rest of the day. Can anyone tell me what is going on?
|Tom W Clark||
posted 02-27-2002 09:47 AM ET (US)
Probably the S.L.O.W. program at work. It limits rpm's if there is a low oil situation or an overheated motor.
posted 02-28-2002 12:15 AM ET (US)
Let me start by saying I have no clue what I am talking about.
I own a 1985 Johnson 150.
I have a similiar issue. While underway the rpms sometimes drop from 4000 to 1500 or so. In neutral the engine will rev up to 4000+ rpms. Then out of the blue I am back up on a plane. Pumping the bulb does not do anything. My year motor does not have S.L.O.W. so I know that that is not the problem. My boat is out for the winter but in the spring I plan on doing the following:
1) Change plugs.
Question - if one cyl stopped firing what would the symptoms be? I was thinking that it would lose rpms under load but not under load it would rev fine? Is this right?
Hope this helps!
posted 02-28-2002 12:22 AM ET (US)
One more quesiton -
When one cylinder is missing is it clearly noticable? Should you need to use a timing light to find out?
posted 02-28-2002 08:21 AM ET (US)
I had an '85 115 that did the very same thing. I acted like the choke was being pressed. I tried changing the fuel line, rebuilt the fuel pump, and bought a new electric choke valve. Never did fix it. Bought a new motor as the parts were starting to cost more than the motor was worth.
posted 02-28-2002 09:14 AM ET (US)
I have a 1987 70 hp Johnson that did the same thing the last time I had it out. In talking to two different mechanics about it, I got two different ideas. The first one said that the motor had high and low rpm coils, and that if the high rpm coil was not functioning properly that you could get the symptom described in this thread. The second mechanic indicated that motors of that vintage sometimes would have carbon build up, particularly on the lower cylinder, and possibly score the cylinder walls or damage the rings. The second mechanic said that they have a special flexible optical thing that they use to check for this condition so they don't have to take the motor apart to find out if that is the problem. I don't know if either of these ideas is correct or makes sense. I thought about doing easiest things first and replacing parts that were within my level of expertise, but I would rather be fishing. Besides, my motor does not have tilt and trim and has spent alot of time in salt water. I am trying to decide weather to fix, buy new, or find a good used motor. Kelly
posted 02-28-2002 09:40 AM ET (US)
I don't think it was the cylinder walls, at least on mine. My compression was 118, 120, 120, 125 which isn't too bad.
posted 02-28-2002 09:41 AM ET (US)
Well let me start by saying misery loves company.
My 1987 150 evinrude is doing the same thing. Usually clears up in 15 min. or so although sometimes doesn't do it all.
I have suspected it is not fuel because pumping the ball, pushing the choke doesn't help. My vro has been disconnected for some time which pretty much rules that out.I keep checking the compression and they all seem to be within a few # of each other.
My mechanic says "electrical not worth putting $ into that oldie goldie I can sell you a new motor". I haven't bought a new one yet because when my motor runs it runs like new and I can't see spending all that $$$$$.
As for you kelly, I had a 1983 70 (no t&t) on my old 15 and ran it close to ten years in salt. I would love to know how many hrs I put on that engine. I got it in high school so I was very hard on that boat. Anyway I spent more on rebuilding that motor than a new one cost. I blew 2 cylanders due to high revs and stuck rings. It was a mess I should have known that is why I am reluctant to do too much to my 150. Just before I sold the 15' I did the lower unit ($$$$) paint job and then it developed the bogging problem. Two younger mechanics took the boat for a week or so and they said they tried everything (I don't think they made any money off me). Well finally they took off the exhaust plates and saw alot of Carbon. They chiseled out the glasslike carbon and it ran fast again. So it is something you could try, just be careful not to bust any bolts.
As for the rest of us I hope we can get together and try to get to the bottom of this problem. I sure would like to get a few more years out of that motor.
Good luck to all!
posted 02-28-2002 11:10 AM ET (US)
I got the impression that the carbon build up problem did not necessarily deteriorate the compression since the carbon build up was on the lower side of the piston and lower ring. Does that make any sense? Kelly
posted 02-28-2002 12:28 PM ET (US)
Kelly, I'm no expert. But I think that any thing that gets between the piston and the wall will scar the cylinder. Thus reducing compression. I could be wrong though.
posted 02-28-2002 02:23 PM ET (US)
The way I understand it, which may be wrong, is that the carbon builds up on walls of the piston and cylinder on the end of the piston away from the firing chamber. Thus, one or more of the rings may be fine, and the cylinder walls on the top part, the part near the firing chamber, may be fine, but there may be carbon build up and damage on the crank case end of the piston and cylinder. That is why I think the mechanic used a flexible optical thing to look at the back side of the piston and cylinder. The top part of the piston and cylinder could look fine and compression could be good, but there could still be carbon build up and damage on the crankcase side of the piston and cylinder. I wish someone that really knew could jump in here. Kelly
posted 02-28-2002 03:32 PM ET (US)
Carb! Float stuck and then unstuck or high speed circuit was clogged and cleared out. Run some techron through it and clean out those carbs. They did not have the SLOW feature in 1987 so cross that out. I will put money on carb was gummed up.
posted 02-28-2002 04:18 PM ET (US)
I bet coil(s). David
posted 02-28-2002 04:20 PM ET (US)
Another thought, if it is a carb then it should be fixed before you use it again or might damage head. D
posted 02-28-2002 05:05 PM ET (US)
These are replies to a post I made on another forum:
Posted by: 12Footer
What you have described is a fuel delivery problem. To confirm this, have someone reach back and squeeze the primer bulb a few times. If the primer ball has collapesed, the tank is not venting, or the pickup tube in the tank is clogged.Make sure the gas tank is venting (getting air to replace the fuel the engine is burning). It can be anything from the vent screw on the tank,all the way to the back side of the carb. Air leaks in a fuel hose, bad primer ball,anti-syphon valve inside the tank,fuel pump check valve or diaphram, clogged jets in carb,or fuel filter.
Posted by: keiser
Could be the ground on a coil? A fouling plug? A bad plug wire? Sounds like to me it is losing spark to one cylinder and then getting it back. A bad connection somewhere along the line from the coil to the spark plug, if I am right.
Check magnets in flywheel, then ignition system check with peak reading meter. If you can get it up to 5000 rpm in water in gear running smooth, trim up and watch the tach. If the tach drops 300/400 rpms the stator is bad.
A lotta good suggestions.
posted 02-28-2002 05:40 PM ET (US)
I have a Evinrude 1978 140hp. 4 cylinders
Last season I put my Whaler Revenge in the water and took off. The engine ran in idle great, but when you went to get on plane, it just bogged down. It was running on two cylinders. I had my mechanic with me and he changed the power pack on the port side handling the two malfunctioning cylinders. It took off on the next try and ran great.
Later in the season the engine would power up initially and then loose power and at times go to idle and cut out. The valve in the bulb was not working. Once I changed the bulb I've had no more problems. Runs like a champ. Hope this helps.
posted 03-01-2002 08:11 AM ET (US)
I don't think it was a missing out cylinder in my case. Once I had a spark plug wire come off and you really couldn't tell except it ran rough at idle, and was a little low on power. I though it was fuel delivery for sure but I changed everything with the fuel system. I didn't clean the carbs, and in retrospect I wish I had tried this. The carbon thing Kelly talks about would be the next thing I might try. We have a borescope at work I could use.
posted 03-01-2002 08:51 AM ET (US)
I am particularly drawn to this advice from unknown participant "Clanton" as cited by tlynch:
"Check magnets in flywheel..."
Exactly what do I check the magnets for?
"...then ignition system check with peak reading meter."
Check what parameter of the ignition system? The primary voltage to the system? The high-voltage spark output? The current? The resistance? And with a peak reading meter?
"If you can get [the crankcase speed] up to 5000 rpm, in water, in gear, running smooth, [then] trim up and watch the tach. If the tach [reading] drops 300/400 rpms the stator is bad."
Can someone elaborate on what is happening here? I need to see some connection between the two events.
posted 03-01-2002 10:52 AM ET (US)
Elaboration....too many chefs in the kitchen:) Powerpacks do not usually came back to life. When they die, they are dead. Powerpack, stator etc would cause bad idle usually as well. Could be coil or plug but that would also affect idle and coils usually cut out once hot, not cold. as far as fuel management and bulbs, vents, etc go....yes very probable but it would not just "kick-in like a plug clearing itself on a 2 cyl. This is a V6 and 1 cyl down would do as dan said. The fact that it just kicked in and went leads me to believe a float boat stuck. If stuck bowl it would idle fine due to float is in idle mode. anything over this it would basically run out of gas until brought back to idle. If float unstuck it would kick-in like a banshee and never do it again until she sticks again.
With the crap gas these days, it is very common to stick a float or needle & seat. My 90 Yamaha sat for 3 weeks and the needle stuck. I beat the heck out of the carb with a screwdriver and off I went. I then did a techron cleaning and she was good to go.
If you have an OMC or another type that the choke is actually an injection of gas, this is an easy way to tell. When running like heck bump the key and if she picks up for a second....carbs are crappy.
posted 03-01-2002 11:18 AM ET (US)
I have tried to push choke and pump bulb neither work. It does miss at idle too sometimes. My money is still on electrical. I've also been told the "magnetic story". I will look at it again at night, but the problem is this roblem is somewhat intermittant.
posted 03-01-2002 01:26 PM ET (US)
George I have only been talking about the first poster question.
In your case intermittent is usually electrical if key push aint doing it. The "choke" on an OMC and some others is actually an enrichener that squirts gas passed the carb into the cyls. If this works then you have a fuel problem....somewhere.
posted 03-01-2002 07:39 PM ET (US)
Padrefigure - I agree with BS's analysis. I think it has something to do with the carbs, stuck float or temporarily dirty jets. At the beginning of one season, my 1987 150 would rev up some in neutral, but when I put it in gear and advanced the throttle, it would just konk out. Diagnosis was dirty high speed carb jets. Ultimately needed a jet cleaning/carb rebuild. With that 150, make sure you use a fuel filter/water separator and make sure that all fuel lines are tight -- no air leaks!
George - Intermittant missing at idle might be caused by dirty check valves in the low speed fuel circuit. At least that's what my mechanic told me when my 1987 150 VRO would cough at idle, sometimes enough to konk out. He claimed to have cleaned them out during one winterization when I complained about the missing at idle and sure enough I never had that problem again so I believe his diagnosis.
Tlynch -- a single missing cylinder on a V6 shouldn't be too difficult to notice. It will run a bit rough througout the rpm range. One way to tell is to run at WOT. If you don't have all cylinders, you won't get the correct WOT rpms. Another way is to sequentially pull one wire and see if it runs poorer at idle. It should run poorly each time except when you pull the wire on the cylinder with a bad plug or coil. I seem to recall many years ago that I had a power pack malfunction while underway. When one malfunctions, you will notice it because you lose all three connected cylinders and the 18 OR will fall off plane. As I recall, ocassionally, my pack would spring back to life so you had to make sure you were hanging on. Based on BS's analysis about packs not coming back to life, I vaguely recall that the pack wasn't bad but wasn't functioning properly because the voltage regulator went bad or something. I would do 1-3, but if the problem continues skip 4-6 and let a good mechanic that really knows the OMC crossflow V6 have a crack at it for an hour or two.
posted 03-02-2002 01:35 PM ET (US)
Let me further describe what I call the "miss". It is constant revs up and down about 1,000 rpm or so. Like a switch on-off on-off then when I push the throttle down it wants to die (but doesn't) this problem soon goes away 10 min later when hot. I might add that my tach when under power jumps over 10,000 rpm so it suggests an electrical problem maybe voltage reg. I sure would like to fix this it is killing me.
posted 03-02-2002 02:08 PM ET (US)
George - an erratic tach can be caused by a bad voltage regulator. When mine went, the tach was all over the place. As previously mentioned, I believe that my power pack was not operating properly when the regulator went. Regulator replacement is a relatively simple task and not very expensive as I recall. When mine was replaced, the motor was about 9 - 10 years old. My mechanic was amazed that it was still the original regulator. Apparently they don't last more than several seasons on that V6. I'd try replacing the regulator and see if some or all of your problems disappear.
posted 03-02-2002 07:39 PM ET (US)
Padre- Please get the engine fixed pronto so we can find out who wins!!!! Thanks David
posted 03-06-2002 09:31 AM ET (US)
Well I went out sunday and the engine ran fine. I think my engine runs bad every one in six or so. Do any of you guys hav that same symptom or are your problems more frequent? Any progress?
posted 03-06-2002 11:31 AM ET (US)
Hi Steve, You shouldn't have any carbon build up considering the number of hours you have run recently but may have some varnish in the carbs.
A quick, cheap fix is to spray carb cleaner into the carbs and inject a can or carbon out into the red fitting near the throttle linkage. Add a bottle of carb cleaner to the fuel tank and run that. This should eliminate most of the build up problems.
Recent cold spells and dry air probably clogged the carbs slightly.
good luck, Jim
posted 03-09-2002 05:59 PM ET (US)
The magnets are glued in the flywheel with epoxy, they come loose,move around inside flywheel, sometimes break and chew up the stator. If the magnets are unbroken they can be repoxed to flywheel.
posted 03-11-2002 07:56 PM ET (US)
MISERY DOES LOVE COMPANY! Bet I got a grand in my 87 Johnson trying to fix the same problem, runs fine out of gear, in gear, bogs down and dies.
Rebuilt carbs, drained gas tank, installed Racor, replaced all fuel lines, bulb.
Mechanic now swears I have bad Stator, whatever that is. $200 later, I have new Stator. Haven't had chance to run it yet to see if problem solved.
Will let you know.
posted 03-12-2002 11:01 AM ET (US)
youn don`t have to guess what the ignition problem is they can be tested with meters, your mechanic should be able to tell you if stator bad or good, and you may have other problems with the stator. Put the boat in the water connect meter to pack out to coil, as boat comming on plane or when running full throttle when it boggs if ignition the meter will dip. check all cylinders, sometimes you can do the same thing with timing light, each time engine misfires, timing light will blink. Once you locate bad cylinder/s simple to backtrack to check pack, stator, timer, genric manuals not always clear on check stators on engine that have Quickstart.
posted 03-12-2002 02:45 PM ET (US)
The above post not so hot, could not edit. You can search Iboats.com, engines/motors. A multimeter with DVA adapter or peak reading volt meter will test all OMC cd ignition, except maby the fuel injected engines.
posted 03-14-2002 10:20 AM ET (US)
I went with the stuck float theory this weekend with mixed results. The engine balked a couple of times, but after letting it idle for a good while, run all day without a hiccup. Unfortunately, the lower unit went out on the way back to the marina. (Sheared drive shaft and broken pinoin gear.) I will continue to try to isolate the fuel/electrical mystery and report back results.
posted 03-14-2002 10:59 AM ET (US)
That could have been your problem to begin with. You get a lower locking up and she will be like driving with the brakes on.
posted 03-14-2002 02:09 PM ET (US)
Welcome contributor clanton. Thanks for the clarifications on your troubleshooting advice. It is appreciated.
posted 03-18-2002 11:42 AM ET (US)
Check the ground wires on the coils. Mine were badly corroded. I haven't had the problem occur again since. Just in case I am armed with a timing light to see if I have spark on the coils when/ if it misses again. A mechanic told me if it is more than one coil I should swap the packs to isolate if it is in fact a pack problem. I am very curious about this but my engine won't do it anymore. I will keep you guys posted but I have found a good deal on a new motor so my old one will not be around for much longer.
posted 03-21-2002 11:28 PM ET (US)
Replace the fuel pump..fb-it is not electrical
posted 03-22-2002 09:18 PM ET (US)
Turns out the top end problem was power packs. Operation was intermittent making the problem tougher to nail down. Now with a new drive shaft, two new power packs and a MUCH skinnier wallet, I am good to go. The white bass are calling...
posted 03-29-2002 09:25 AM ET (US)
Well last night I snuck out to run the boat and much to my surprise it ran the worst it ever has less than 1/2 power. As we discussed earlier you know I have had this ignition problem but was not 100% sure what it was. Then the engine ran great for a spell, but last night as soon as I started it it missed. As I mentioned earlier in this post a mechanic suggested I test spark with a timing light to help diagnose and to possibly isolate the power packs. Well with the assistance of a friend I checked it out and all 3 cylanders on the starboard side were not firing corectly.
I have decided to dive in and buy a power pack and see what happens. Thanks to all who supplied advise.
Over and Out!
posted 03-30-2002 10:27 PM ET (US)
Well I did confirm that it is the power pack by switching both packs and following the spark with the timing light. I had to do this because the new factory $120 power pack was a dud! Now I am waiting till next week to see if they will exchange the part.
So far NO good!
posted 05-09-2004 04:55 PM ET (US)
I have a 1986 Evinrude, 75hp, that also bogs down when you engage the trottle over 5 knots. If you press the choke once, she usually will spring back to life and shoot up to 30 knots or so. The motor was recently rebuilt, new pistons, head and the carbs rebuilt. A new fuel pump was installed last year. The compression tests OK. My mechanic has been trying to tell me it is because Tempo tanks are crap, but I tried other tanks and had the same problem. Usually once I get her up on plane, she runs great. However when I turn her off and sit for awhile, same problem, then I hit the choke and she goes. I think I will take her to another mechanic but thought I would check the board first. Any ideas?
posted 09-03-2005 08:28 PM ET (US)
I now know what is causing the lack of power and bogging problem on my '84 Evinrude 175 V6. After checking lots of things, plugs, wires, carb bowls inspected, filters, etc..
I decided to change the fuel pump setup to electric. Went to Pepboys and asked to see electric 12 volt DC fuel pumps. They had two types, Carter (which I did not even look at) and Purolator. I liked the size and the cost ($30) of the PRO 04SV POSI-FLO so I bought it. I reasoned that even if this didn't work out I would still have a nifty pump to easily transfer fuel from tank to tank if need be.
I also purchased a Purolator F21111 Fuel Filter, which is clear, allowing you to see that fuel is present. This connects to the fuel inlet nipple on the motor. From the filter outlet through clear reinforced tubing over to the electric pump inlet. Then from the pump outlet to the existing line feeding the three carbs on my 175. I grounded the black pump wire to the lower right mechanical fuel pump mounting bolt. Next I extended the red positive pump wire to reach up and over following the existing wiring harness to get to the screw-terminal strip on the opposite side of the motor.
A quick check showed me a connection that is hot when the ignition switch is in the ON position, and off when the switch is OFF. This is where I hooked up the pump's red wire. You must be careful not to leave the switch on for long with the motor not running.
Out to the river for a run and like magic, my power has returned. Except for full throttle that is. Even this new electric pump cannot quite keep up with the demand of the three carbs over 4000 rpms. That limits me to about 40 on the speedo. It may be a different case with 2 carbs or only 1. Above that I get a bogging oscillation until I back off on the throttle.
I will replace both my standard pumps with high performance models. This was more or less a test that also gets my rig back into the water when I want to go out, until I get the new mechanical pumps.
posted 07-26-2009 09:16 AM ET (US)
I was having the same bogging problem when throttled up on my Evinrude 225 Ficht . I had the now common problem with ethanol fuel and I did a drain down and changed fuel filters twice. I was about to change out the fuel pump but decided to try all the suggestions here. It turn out that during the pump out of my 40 gallons of bad gas I disconnected the intake on the water separator to use that line for the hose. When I re-attached it I had failed to use a hose clamp on the fitting. I put on a nice tight clamp and it seems to have cured the problem. It must have been sucking air and causing the fuel to pulse.
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.
Powered by: Ultimate Bulletin Board, Freeware Version 2000