Moderated Discussion Areas
ContinuousWave: Whaler Repairs/Mods
Raising outboard one hole-How?
|Author||Topic: Raising outboard one hole-How?|
posted 07-09-2003 07:15 AM ET (US)
1976 85 hp johnson 4 cyl, 1978 Newport.13 1/4 x 17 prop, only turns 4000 rpm. I went back and read the owner's manual, it describes raising the outboard to maximize performance. Raising it until you get cavitation on turns, then lower one hole. However, I don't know if to raise it you must have a hoist, or if you can put the skeg on a scissors jack and put it up that way. I'll probably not have any help when doing this, so your experience is appreciated. Curtis
posted 07-09-2003 09:00 AM ET (US)
Since you will not have any help when you do this, I highly recommend that you use a come-along and put ropes over a few rafters in your garage or a very strong tree branch. The skeg was not designed to take that kind of weight.
posted 07-09-2003 09:21 AM ET (US)
Sounds like more of a problem then just height.
Your about 1,500 rpms below where you should be.
I'd do a compression test on that engine before doing anything.
If it checks out ok, you can put a jack under the bracket & tie a couple ropes from the middle cleats [ if you have em ] around the engine, then remove the 2 top bolts & just loosen the bottom 2.
Then jack it up a hole or 2, the holes are only about 5/8" apart so it's not that your moving it all that much.
Remmber, just loosen the bottom bolts enough so the bracket will slide 1-1/2 inches up.
Just for safety sake, put a 4 x 4 tight under the skeg in case your jack slips.
posted 07-09-2003 10:26 AM ET (US)
Thanks, guys. For two years this motor used to only turn 3200 rpms until recently when I switched to the 13 1/4 x 17. Now it turns 4000. If the compression is down in one cyl (rings),I'll probably need a different motor anyway. I guess I could do the combustion chamber cleanup spray, but I should do that anyway, right? Maybe one of the power packs has gone out, but I don't know how you tell.(If it has spark at the plugs is power pack ok?) My thought is, if I can get it to get close to 5000 by raising a notch, I'll just ride it until it drops. I'm in a lake, so if it fails it's just inconvenient, not life threatening. Thanks for the help. Curtis
posted 07-09-2003 12:50 PM ET (US)
If you were over propped i'd say go less on the pitch big time, but this is much more then a prop problem.
Something to keep in your mind.
When your over propped & can't even get close to you optimum rpm range, it's not just the wot that hurts the engine, it's all the way through the rpm range, from 1,500 to 4,000 rpms.
If you ran that engine for any length of time while it was only able to twist 3,200 rpms, i'd bet money your engine is now shot.
Thats a sure way to ruin an engine real, real, real, yeh, 3 reals, fast.
The worst thing you can do to an engine is run it without oil, next is run it hot, then over propped.
posted 07-09-2003 01:03 PM ET (US)
What would be the areas of concern? Would overpropping ruin compression? Flood the carbs? Put stress on the crankshaft? Gearbox? Obviously I know very little about this, but where should I look ? The motor starts every time,(and has started and run now into its third year), pops the boat on plane, and now (at 4000 rpm) has a pleasing throaty howl. How will I know that it's shot? Thanks again, Curtis
posted 07-09-2003 04:39 PM ET (US)
Think of it this way.
Your towing your boat with your truck, your driving on a nice flat hiway, then you come to a mountain range & the road gets steep, your foot is to the floor board & your still in either 5th gear if it's a stick, or your in Dr#1 & your only going 30 mph wide open & the engine is only turning about 2,600 rpms where it should be in 3rd gear or Dr #2 & turning 3,600 rpms.
How long do you think your vehicle is going to last if you ran it like that everyday ?........not long, thats for sure.
If you have run that engine for 3 years as you say, I wouldn't be surprised if it isn't already shot.
You just put " BIG TIME, HUGE" stress on all the moving parts.
I would be surprised if you have 70 lbs compression in that engine.
Don't forget, a boat is "ALWAYS" going up hill, never down hill, theres no such thing as coasting in a boat unless your in a following sea & you coast down the front of a wave once in a while.
From the sound of things, [ from what your saying ] I wouldn't be surprised if the engine isn't already shot.
You better have a qualified tech look at it, but don't be surprised if he says it's had it..
posted 07-09-2003 11:04 PM ET (US)
I'll address the original question. To raise the outboard, I use the trailer jack and drop the tongue as low as it will go. Then block under both sides of the cavitatation plate as close to the gearcase as possible. Crank tongue up to take some weight off the bolts, then remove the top bolts and loosen the bottom bolts CAREFULLY. Crank up tongue some more until the desired set of holes is reached. Reinsert top screws and tighten all bolts.
posted 07-09-2003 11:41 PM ET (US)
I doubled up the 2x6 rafters in my garage and used a come-along with two small(1/4?) shackles. It worked fine, the motor hangs pretty plumb and hanging it, rather than jacking it, lets you float it around a bit while lining the holes up. Joe
posted 07-10-2003 07:15 AM ET (US)
Acseatsri- That is a great idea. Thanks all! Curtis
PS- I'll keep posting to let you know what happens about the rpms. Any ideas on how to check if power packs are good?
posted 07-10-2003 05:31 PM ET (US)
Nope, only way to check, is check the intake of the power & if thats ok & the output isn't then it's bad.
Pack sometimes are intermitent & even if their good, theres no real sure way to check it.
posted 07-10-2003 06:03 PM ET (US)
1. I used acseatsri's method of raising my engine and it worked great for me on my 150HP Evinrude.
2. I was having a Power Pack problem earlier this year. Someone on this Forum, and also my Evinrude mechanic, said you can put a Timing Light on each individual spark plug wire to see if it is firing. If all plugs on one side of the engine (OMC) are not firing, then it is most likely your Power Pack. If only one spark plug is not firing then it could be your coil.. Of course, the problem has to show itself when you are checking it... Intermittent problems are always hard to diagnose unless they show themselves...
posted 07-10-2003 07:19 PM ET (US)
Took it out today once I was sure I had the bushing in front of the prop(13 1/4 x 17) right. 4100 rpm, two people, 24 gals fuel, two bass seats and pedestals, front trolling motor,two batteries, bimini, RPS, 15 # anchor, spare old (wrong wrong wrong )prop. 33 mph GPS. I should add the bottom has been painted with a white spray paint, not very slick, and gradually peeling off revealing gleaming gel coat. Also, the motor is right on the transom. I can move it up two holes max, and I will this weekend.
While out of the water I will change the plugs and do the old trick of laying a plug next to the cylinder to see if it's firing.Also the decarbonizer.
If none of that bumps the rpms I have an old 12 3/4x15 prop to give a twirl. As a concession to all I will actually check the compression when changing the plugs. Question- should I go both holes in one jump? Thanks, expert help (seriously) Curtis
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