Outboard Engine Help

[gyroman]

Automan1223 or anyone else I need help!!!

I know this is cheesy asking help on my outboard motor in a rotorcraft forum but it is in the Off Topic section.


I have a 1980 60 HP evinrude motor that has been giving me fits. A little history: I had a burned piston so I had the engine rebuilt. When complete the engine would not go above 3000 rpm. Took it back to the shop and they found a bad powerpak. Since then I put about 20 hours on it with no problems at all.

Now my brother took it out and on the way back in the engine dropped about half RPM's. It only runs about 3500 on full throttle. The engine will start up on almost the first crank when warm and will run fine out of water. Put it under load in the water and only get about 3500 rpm. I tried a new powerpak again but no luck same problem.

Oh, and I rebuilt the carbs after this problem (no luck same problems) so no blockages anywhere and there's no real carb adjustment other than syncing the carb linkages.

Any ideas? Would a coil being bad cause this? Or something with the stator? Any help is greatly appreciated....

To make this more rotorcraft related I add the following:

What happens when a make a downstream turn close to the pier??? :D HEHE

And... if I get this boat running I can sell it to BUY MORE GYRO PARTS....

[Chuck Irby]

Toby, what are the compression readings?

[gyroman]

Compression was good... approx 140 in each cyl... still is checked it a week ago.

[Chuck Irby]

Toby, I am assuming that one cylinder is not firing and both are getting fuel. Is this correct? If so, yes, a bad coil could definitely cause the problem.

PS, did you check compression after the last problem?

[gyroman]

I swapped the coils around and it had the same problem, but in a two cylinder engine I guess that wouldn't make much difference. One would always be out. But if I remove the spark wire while running the engine quickly dies, no matter which cylinder I pull. (not to mention a nice shock when I do it.)

PS yes, compression is still good at approx 140psi.

[Chuck Irby]

Toby, something doesn't sound quite right. Are you saying that if you pull either plug wire, it'll quit?

[gyroman]

Yes the engine will die if either plug is pulled.

[Chuck Irby]

Toby, if both cylinders are getting fuel, both plugs are firing, and both cylinders have 140 pounds of compression, it should run like a new one. I'll give it more thought. Meanwhile, it wouldn't hurt for you to make sure that all of the aforementioned is, in fact, true.

PS, remove both plugs and make sure the engine turns over freely and smoothly by hand.

[gyroman]

I'll try to verify everything tonight if I have time. I know the compression is right cause I was worried about it the most. (You know spending all that money to find out it is screwed up again).

Appreciate all the help......

[Ron Marlett]

Toby
What year, make and model is this engine? Does it have a single ignition coil(with 2 plug wires coming out of it) or 2 completely seperate coils? Some 2 cylinder 2 strokes using a CDI ignition employ a single coil with each end of the secondary coil winding going to a spark plug. Both plugs fire at the same time(near TDC on one and BDC on the other). The circuit goes from one end of the coil secondary, down through one plug wire, jumps the plug gap and travels through the cylinder head to the other plug. The energy then jumps that gap and returns to the other end of the coil via the second plug wire. Removing either plug wire would interrupt the circuit and stop both plugs from fireing. And your body would absorb the energy giving you one hell of a shock :) .

Your 1/2 max RPM symprom sounds like a cylinder not fireing As I am sure you know you need Compression, Fuel, Air and spark. Sounds like you have good compression so you are missing one of the other 3 or you have too much fuel/oil on one cylinder and it is fouling the plug on that side.

What do the plugs look like?
Are you running Pre-mix or oil injection?

[C. Beaty]

Check the reed valves, Toby. Sounds as if you could have a broken reed in one of them.

A broken reed will make it spit back through the carburetor but if you always run with air cleaner in place, you wouldn't notice.

I don't know whether or not these engines have ignition advance linked to the throttle. It can be done electronically. If it appears to have mechanical advance and most likely it does, make sure that when you open the throttle, the ignition pickup (under the flywheel) moves with it. Retarded ignition prevents full power RPM and burns pistons.

[Chuck Irby]

Those are good thoughts, Mr. Beaty. However, I have never seen a stainless reed valve break. Have you? Too, it sounds like it's running too smooth for it to be a reed. I used to run fiberglass reeds, and could loose a small part of one, on a six cylinder, and notice it immediately. In addition, why would it immediately die with the removal of either plug wire? Something just doesn't add up, IMO.

[automan1223]

The first thing you have to check is the color and condition of the plugs. If a plug is not firing it will be 1 of 2 conditions,

wet soaked with fuel

or

black sooty fouled.

any outboard with a weak condition will display the power you describe.

once you check the plugs and have an idea what is going on if you have spark and they are not a shared igniton coil set up and you pull a wire and the engine dies then you got a bad coil somewhere. if this is a 4 cyl with 2 coils then you got a shared ignition and you could have the wires mixed each coil wire must go to the correct coil. output terminal.

If you have checked all the basics there are 2 obscure things.

well 3

fuel pressure sucking air in the lines causing low fuel supply


exhaust gasket leaking around power head inside the leg, a small amount of fumes will travel up the leg and choke up the engine. run with the cover off and see what happens.
I use great stuff to seal around the leg gaskets and the power head, most techs reuse the old gasket, its a pain and they never seal right anyway. They all do it and it is a primary why outboards have trouble starting and power output.
it cant make power if it is sucking exhaust.....

last problem is the worst requires teardown and heartache. there are carbon seals that seal the crank in the block between the cylinder chambers and if they crack or leak it will produce the symptom you describe. Most of the time on the tall boy merc outboards. since this is an evenrude then its still possible but the only way to know it is to have the whole thing torn down.

Check all your basics first. I have done A LOT of research on these engines. champion has a lot of new plugs that you can run and I got a tremendous amount of power out of my engine by going to extended core plugs. with correct heat range. throw a new set of plugs at it just for drill. 2 strokes are finiky

what plugs ?

how many cyls ?

Jonathan

[gyroman]

Ron,

The engine is a 1980 60HP 2 cyl evinrude. It has two separate coils per cylinder. I believe both plugs looked brownish/black and a little wet but haven't checked that in a while. I do remember they both looked about the same. I'll add that to the list of things to check. Should I let the engine run for a few minutes then cut it off and check the plugs?

Chuck,

I had thought about checking the reeds but I have to take off a lot to get to them which is why I procrastinated.

The carbs do have an airbox on the front so you can't look directly down the throats.

The engine does have the ignition advance linked to the throttle. When you increase throttle it does move a linkage which changes the timing. I guess I need to read up on how to check the timing on this engine but the shop book I have is not really that clear and the engine was working fine, just all of a sudden started having this problem.

Thanks all, gives me more items to check out....

[gyroman]

Jonathan,

2 plugs (think they are champion, I'll have to verify)

2 cylinders

2 coils

2 carbs

1 power pack.

It runs the same whether the top cover is on or off. I had it at the lake a couple weeks ago checking things out. I had my wife driving at about 2000 rpm and pulled a plug wire, almost fell outta the boat (from the shock) and the engine immediately died.

I'll try some new plugs this weekend but I think I did that a while back but certainly doesn't hurt.

[Ron Marlett]

Well if it was only running on one cylinder and you pulled the wire to that cylinder then it would die:) If it is only running on one then you might have a bad coil/wire, a fouled sparkplug or a misadjusted/failed carb on the dead cylinder. If you havn't looked at the spark plugs in a while, how long ago did you put in NEW ones?

[Brent_Brown]

If it appears to have mechanical advance and most likely it does, make sure that when you open the throttle, the ignition pickup (under the flywheel) moves with it. Retarded ignition prevents full power RPM and burns pistons. as chuck said and i think that is the case.

PS do not pull the plug wire when it is running the High volt have to somewhere and could hurt you or the motor.

I work in a dive locker and we have about 60 motors set up just like the one you have and it is acting like the link to the advance is not working right.

[automan1223]

Checking the timing requires knowing where to set the marks on the flywheel to the engine block/ frame and to match the marks on the timing sprocket / housing with the arm set to idle if memory serves me correctly. pretty straightforward but if you have a 60 hp with a 2 cyl you lose a lot of power with a low cylinder. if the cog belt is snug then I would rule out the ignition belt. throw 2 new spark plugs on it and see what happens. 2 strokes on outboards are so fickel. The REAL problem is that the oil fouls the plugs, the thermostats are set for 140 f. this is too cool. even making your own housing like I did and playing around with stuff after a cold start, to adequately clean off the plugs you need to flare the engine temp to 180-200 depending on water temp and fuel quality/octane. Once the plugs would really get hot and clean off my 1966 bucket of bolts would run better than the 88 special engines they made with efi. It is also IMPORTANT that you DO NOT USE the newer synthetic oils with the OLD engines. Use the OLD twc 2 or 3. dont use the 4 or 5. The synthetic is meant for high hp, new oil injected Finely tuned machines.....

The old engines dont like it at all.

Look change the plugs and see how it runs.

J

[C. Beaty]

Pulling plug wires on running engines kills more ignition coils than ever die of natural causes. Internal arcs.

[GyroRon]

I got your fix. Take off the old Evinrude and sell it cheap to some fixer upper type of guy and find yourself a new or barely used Yamaha or Honda Four stroke outboard and be happy again!!!

[gyroman]

Ron,

I'd love to get a new Honda or Yamaha, hey, you buy gyros at the drop of a hat why don't you buy me a new engine??? :D :D

And while your at it find some old fixer upper for my old engine....

Didn't have much time yesterday to mess with the engine but did fire it up and pull the plug wires off the cylinder (oops chuck!!) and it is definitely the lower cylinder not firing. I plan on getting the new plugs and most likely buying some new coils for it as well. Just looked them up and the coils only run about 18 bucks a piece.

I could have sworn I put new plugs in it before but looking at them it may not have been the case. May have been another engine I was working on at the time.

You guys are great... thanks for all the advice. I'll report what I find out...

[Chuck Irby]

Toby, now it all adds up. No fire, huh? That makes a lot more sense.

[gyroman]

Well Chuck it actually did have fire.

I pulled the lower last night because I know I pulled the upper one when I was out at the lake a couple weeks ago (it was the only one I could reach from inside the boat). When I pulled the upper at the lake the engine died immediately.

I had the engine running at about 2000 rpm, then pulled the lower spark plug wire off, (I did it with some rubber handled pliers this time to avoid the shock). The engine made no hesitation, strange noise or anything, just kept on running exactly the same. However, a spark started jumping from one corner of the coil to the mounting bolt on the coil housing. It was getting dark so I could visibly see it with no problem. So it was getting fire to the coil but maybe not all the way to the spark plug. So I figured I would get new plugs first then go with the new coils next.

[gyroman]

Well, I got new plugs and put them in then tried running the engine for a few minutes. When I was done I pulled the plugs out and checked them out. The top plug showed a slight brown color. The bottom plug showed no sign of firing and had just a small amount of fluid on it. Not wet but just moist. I pulled the carbs off and looked at the reeds. The top reeds showed some fuel on it but the bottom was bone dry.

Unscrewed the plug at the bottom of the bowl and no fuel came out. Disassembled the carb and found everything to be good... EXCEPT when I checked the intake from the fuel line. Had some garbage in there that completely blocked the fuel from getting to the bowl. Must have missed that when I rebuilt the carbs.

Also bought a new coil since one of them had a crack and I suspect it may have been leaking a spark.

Fired it up and it ran MUCH better. Idled very smoothly. Checked and both cylinders are working now.

Took it out to the bay and put it in the water. Took off and it sounded good then had a good amount of hesitation. Still wont go over 3100 RPM.

I'm thinking a have a problem in the high speed jet now but dont know for sure. When I get time I'll have to rip the carbs off again and check them out.

[automan1223]

if your compression is good then

use a spark tester and check for spark,

2 fuel delivery could still be goppted up Take compressed air to the needel and seat area and blow back out make sure you got good fuel supply and no air leaks.

[GyroRon]

This is what the mechanics at your local marina when to school to learn to fix. Maybe it is time to let them have a go at it?

[scottessex]

The most overlooked thing I have seen when working on motorcycles for years is that when people clean the carbs, they forget to clean the fuel lines and the rest of the fuel system. If there is trash in the lines or tank, it goes right back in the carb when you hook it up. Just a FYI. good luck.

[Chuck Irby]

Come on now Ron. You wouldn't do that yourself. You would do exactly what the rest of us would do. You would keep on with it till you fixed it yourself, and you know it. :D

[GyroRon]

Chuck, yes and no. My time off is better spent on the water or in the air or on my bike etc... I would not want to pay someone else to fix it either, but I wouldn't want to miss half a summer trying to fix the darn thing either. I don't know about Texas, but here in the Carolinas there is only about 1 more month of good boating weather, after that it is too cold. I would want to be on the water.

besides I was only giving Toby a hard time in a jokingly manner. :D

[gyroman]

In Texas, I could go out on the water pretty much any time of year. We get a few cold fronts a year but they only last a few days, after they blow through then its back up into the 70's.

As for taking it to the local boat shop, last time I did that the labor cost me 3 times as much as the parts. I could have replaced every single electrical item in the boat for just the cost of labor. I figured I would go a different route this time. Plus, I like to work on things, gives me greater satisfaction when I actually get it fixed.

[davreich]

Hi,
Don't the ultralighters have a problem with fuel supply causing lower RPM? They have problems with the fuel pump location, vibration to the fuel pump and the most common cause is the fuel primer bulb which most now bypass. Just a thought. Dave :cool:

[Chuck Irby]

Hmmm, my thought is that lack of enough fuel would simply cause the engine to cut out or die, not make it run at a steady lower rpm.

[gyroman]

I'm thinking it does have something to do with the fuel system. Allthough, when I squeeze the bulb, I can hear the fuel rushing into the fuel bowls. Then the bulb gets tight, when running my fuel bulb is constantly tight and I can't really squeeze it anymore.

At a certain throttle setting, say 3/4 throttle I get a pulsing. Like the engine is trying to go to full rpm then cuts back down. This is constant at this throttle setting. If I advance the throttle more it just bogs down. Less it seems to run perfectly fine. I'm thinking it must have something to do with the intermediate and/or high speed jets. I have a (forced) vacation coming up in a couple weeks so should have some more time to work on it then. Kids sports take up every ounce of time I have now when I get off work.

During my vacation I may make up some plates to cap the carbs intakes and do a pressure test on the crankcase just to eliminate air coming in from somewhere.

[Chuck Irby]

Toby, are you sure the chokes are remaining wide open, and that you don't have any vacuum leaks?

[gyroman]

Wide open....

Not sure about vacuum leaks from where? I mentioned I may do a pressure test on the crankcase but other than that I don't see where I'd be getting any leaks from. Just put new clamps on all the fuel lines. I was having some fuel leaks before that, did have stock plastic tie wraps for clamps which I didn't like.

[Chuck Irby]

Toby, have you checked all the tubing, the carb gaskets, the reed cage gaskets, the tighness of the attachment hardware? If yes, a good test is to get a can of WD-40 and with the engine running at somewhere around 1500 rpm, spray around everything except the carb intakes and see if you notice a change in rpm.

[Wolfman]

You know the junk you mentioned was in the fuel line? Some of it is in the carb as well. I just helped my buddy take his lawnmower carb off, and we sprayed brake cleaner through all the air passages, and made sure it exited somehwere in the carb. For 3 years his lawnmower would not idle- but now not only does it idle it also starts at idle, on 1-2 pulls.

He had crap in his fuel line just like you, and stagnant fuel residue in the carb air and fue passages that caused him enough trouble to where the mower would work, but not well. I suggest you remove both carbs, and blow compressed air/ brake cleaner/ choke cleaner through each passage and make sure it exits with a healthy stream somewhere in the carb.

[gyroman]

She runs great now...

I took everyones advice and took the carbs off. Then hauled them over to my dads, he has a high pressure air compressor. Took all the jets out and blew them out.

When I cleaned and rebuilt the carbs before I just used a can of carb cleaner to shoot through all the jets. Not to mention I could not get the intermediate jet out due to it being down a long narrow tube and I didn't have a screwdriver to fit it. I just blew carb cleaner through it so I assumed it was clear.

Got to my dads and decided I was going to completely strip this sucker down. I found an old junk screwdriver that I grinded down the end to fit down the narrow tube and got the intermediate jet out. Then blew everything out with 100 PSI. Put it all back together and took the kids out fishing.

She fired right up and ran like a top. I slowly gave her more throttle curiously waiting for the lull to hit at 3500 RPM. She blasted right through that and away she went. Slowed down and gave full throttle, no hesitation... just up and on top of the water. Drove around for a while just to stretch her prop.

Feels good to get her back running, I calculated and its been almost 2 years since I had it running good. Time seems to fly by when you get to working on other stuff.

I just wanted to say thanks to all who added there knowledge in helping me get this thing running again. Really appreciate it.

Now its time to get back to work on my gyro!!!! (with the occacsional fishing break)

[Chuck Irby]

Way to go Toby. Gkad you discovered the problem. I knew you could do it.

Drain the carbs before yoy set it up for the winter, and that problem won't repeat itself.

[GyroRon]

Sorry to have told you to take it to the shop for what turns out to be a easy repair. I didn't know the last time you " cleaned " the carbs you just sprayed them with carb cleaner, I assumed you had them totally apart.

[gyroman]

Ron,

I took the carbs completely apart when I rebuilt them except for the one jet in the lower carb.

The carb cleaner spray can has a tube that comes with it (just like the WD-40 cans), I used this and stuck it straight in each hole and blew it through. Although pretty forceful I guess it was just not enough umph to dislodge whatever was in there. The air compressor sure did the trick. Once it almost blew the carb out of my hand when I was blowing through the high speed jet!! :D


Chuck,

I usually drain the carbs on all my two cycle engines after every use, unless I plan on using it again within a week. But thanks for the tip.

[jawbrey]

are those plugs platnium if so they dont seem to take rich fuel condition well


james