needing some direction regarding motor problem

[lenniefoug]

I have a 1994 evinrude 88 special. For the most part it has never been a problem and in the scope of things has very low hours on the motor. I recently started it up for the first time this year and after 15 or 20 minutes of running I noticed what sounded like a bad bearing noise I shut it down and turned the flywheel (not sure if that is the right terminology) on the top of the engine. It felt tight with no wobble. I also could hear the compression from each cylinder as I turned it. Today I started it again and the same noise was there. Suddenly after 5 minutes the engine shut down and when I tried to restart it wouldn't turn over at all. I then went up to manually turn it again and this time the flywheel wouldn't budge. I let it sit a few hours and I can now move it but with greaqt difficulty and it seems to want to stick before making a full revolution. So my question to the group..any ideas on what happened. I am not an expert motor guy but do have some basic skills. I would appreciate any advice regarding what the issue might be
Thanks for your help

 

[CATransplant]

Re: needing some direction regarding motor problem

The noise, followed by the seizure of the engine is not a good thing. It sounds to me like it wasn't getting lubrication and a bearing seized. It could be other things, I suppose, but that's what comes to mind.

 

[lenniefoug]

Re: needing some direction regarding motor problem

Thanks for the suggestion. This motor is a 2 stroke and if anything the gas/oil mix is a little rich so it is hard for me to imagine it would be a problem in the cylinders. As for other lubrication systems, I don't have a good feel for them. I think there is a sealed system for the non combustion parts of the engine but I am really not sure as motors are far from my area of expertise..any thoughts
Thanks

 

[CATransplant]

Re: needing some direction regarding motor problem

I wasn't talking about the cylinders. I was talking about the crankshaft and rods. If a big end or little end on a connecting rod failed, you'd get the noise and then finally a seized engine. But, it could also be a broken ring. I'd start by pulling cylinder head(s) and having a look at the cylinders. If they aren't scored, then I'd start thinking about rod bearings.

It's also possible that one of the flywheel magnets has come loose. That will also cause a banging noise and, finally, a lockup. You can check that by pulling the flywheel.

In any case, it's fairly easy to pull the head(s) and flywheel and find if something's wrong in the cylinders or flywheel. If it's in the crankcase, I think I'd think about finding a good powerhead.

 

[lenniefoug]

Re: needing some direction regarding motor problem

Thanks CAT..as I said I have a limited understanding of boat motors. Here's hoping that it is a magnet problem. By the way, how could you tell if it is a magnet problem?

Thanks for all your help

 

[fishmen111]

Re: needing some direction regarding motor problem

Hope it is simple lennie...but sounds mighty familiar to me. I lost a rod bearing a few months back with similar symptoms. I also didn't think it could be because I'm liberal with my oil mixture. What the guys here informed me of, was that more than likely I had one carb running lean enough to not supply enough oil to keep it lubricated. When you pull the head(s), see if you can push any of the pistons without the flywheel moving. Cycle each piston until it just starts to go back down, then push on it. If one moves by itself, you found the knock. Sure hope that's not so in your case, just fyi and good luck.

 

[lenniefoug]

Re: needing some direction regarding motor problem

Thanks for the info fishmen. I wanted to add one bit of insight which may or may not make a difference. I am able to turn the flywheel just short of 360 deg when it binds. I can then reverse direction almost 360 before it binds again. So it appears that there is just one spot in the entire 360 revolution that binds up. I don't know what you call this part of the motor assembly but there is is a square control box that sits aside the motor with two flanged connections. I can hear movement within this box when I am turning the flywheel. Is this normal or is it indicative of where the problem may reside.

Funny thing is that I have had this boat/motor since new 14 years ago and i have been hounding my brother in law to take it for the summer since he has young kids and I use it only a few times a year. He was supposed to pick it up this weekend but I just had to tell him there is a problem. I have never had any problems with this motor outside of the usual T-stats, plugs..etc So here's hoping that I may get lucky and discover an easy fix. As always, any advice would be greatly appreciated

 

[fishmen111]

Re: needing some direction regarding motor problem

You must pull the heads for inspection lennie. If you do not have one, get an OEM shop manual. Your new description could still be a rod or bearing, but almost sounds like a broken ring or loose wrist pin. Pulling the heads is simple and will help tremendously with the diagnosis. Loosen the bolts carefully. They are only tightened to 20 ft/lbs, but are a common headache with breaking off.

 

[lenniefoug]

Re: needing some direction regarding motor problem

hi fishmen, I know you're right about pulling the heads but you need to know that the only head I have ever pulled off is a doll's when I was a bratty little child. Taking things off has never been a problem for me, getting them back on is where I always screw up.
That being said, when you talk about pulling the head, do you mean the thinner, almost face plate like section where the spark plug screws in or the thicker section(maybe 3 to 4 inches deep) bolted to the main body of the engine?

Also I don't know if this will change your thinking or not, but with the movement I did have with the flywheel I was able to determine that all 4 pistons are indeed moving

One other thing, an earlier post from CapT suggested checking the magnets. I pulled the flywheel but I see no magnets on the underbelly. What am I missing on this suggestion

Lastly, I do want to thank you for your advice and patience

 

[tashasdaddy]

Re: needing some direction regarding motor problem

magnets are an integral part of the outer edge of the flywheel, it would be obvious it they were loose. go here and look up your motor, and you can see all the parts http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

also click evinrude manuals at the top of the page, and get an evinrude manual for your specific motor. if you don't want to spend the money. that it to the shop and spend more money.

 

[lenniefoug]

Re: needing some direction regarding motor problem

Hi tashadaddy,

I did get a manual this morning and I also looked at the diagram link. The manual talks about the magnets but doesn't actually show them. Other posts I read talked about glued on magnets. I don't have any glued on magnets on the underbelly of my flywheel. Is it possible that they are integral to the flywheel and if so how would I check that they are still magnitized. I see no residual epoxy marks indicating that exterior magnets were at one time attached nor have I seen evidence of self destruction of the magnets within the motor housing

Thanks for your help

 

[tashasdaddy]

Re: needing some direction regarding motor problem

when you look at the outer rim of the flywheel the metal should look a little different in color where the magnets are. the should be flush with the rim.

 

[lenniefoug]

Re: needing some direction regarding motor problem

Thanks tashasdaddy,

That is a big help. Since there are no pieces missing they must be there, I will check to see if they are still magnitized tonite

Thanks

 

[lenniefoug]

Re: needing some direction regarding motor problem

tashasdaddy,

fyi - I found the magnets, checked them all and they are good. I never would have figured it out without your advice, now I need to tackle the cylinder heads

thanks again