1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

[ijmckenzie]

Hi all,

My issue is I can't seem to get one of my cylinders to fire. Engine cranks up great but one cylinder just won't fire.

I replaced the ignition coil on the bad cylinder also put brand new spark plugs in. So I have good spark all round. I figured it could be a fuel issue so I traced all the fuel lines and found nothing. I then pulled the carbs and cleaned them. Cylinder still won't fire. At this point I'm a little stuck any advice? (Also after cranking up the spark plug on the non-firing cylinder is covered in blackish oily stuff. The other ones are totally dry.)

I also had a look at the reed valves. They look fine (clean, no crack and parts missing). I did notice when I pushed on them with CLEAN (before anyone says something) object the two cylinders that are working sort of made a suction/sealing pop noise. But the cylinder that isn't working didn't make that noise though it did seem to sealed just fine.

Does anyone one have any suggestions??? Seems to me I have air, spark and fuel so I really don't know where to go from here.

Also if you want the full story I posted this a while back w/o much luck.

http://forums.iboats.com/johnson-ev...-wot-help-me-diagnose-601280.html#post4187714

thanks all

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

I was wondering how you tested the wet plug to determine that it was actually firing?

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Good question...I don't have a spark plug tester (I know I should buy one but I'm poor and underemployed haha) so I just pulled each individual plug and held them close to the engine block while I had someone crank the motor. All the plugs were sparking good (blue and long) and I didn't see any difference between any of them.

If ya'll think I really should go buy a gap tester I will though.

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Hey that's a good enough way to test a plug firing. If you have fuel, air and spark then all should go bang I would think. I know you don't want to start throwing expensive parts at the motor until she runs. I don't know enough about marine engines to remotely diagnose much but there should be someone here who has had the same thing happen to them and have a fix. When I got my old Johnson, I started buying new parts for it, replacing parts before they went bad on the water and it started with replacing my power pack which caused me some grief with motor just up and dying. (no spark) Try to keep your post towards the top of the list so someone in the know sees it.

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Right that was my thinking as well. Fuel+Air+Spark and it should work. Thats what I'm hoping is someone has had this problem before and knows whats wrong. A guy on my other post just said that this engine has a history of blowing the #2 piston piston and rings so I am going to re-compression check and see what happens there. Thanks for replying though and I will keep this post updated.

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

ok ya'll brace yourself for the bad news. Compression check came back 125,0,125. Seems something is wrong with piston or cylinder head or o rings or something. To be perfectly honest I'm not sure what the next step is so if anyone has delved this far into their motor feel free to give me some tips...otherwise I guess we can call this thread closed. I'll prob make a new one to see if I can get some help taking the pistons apart.

 

[Will Bark]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Have you pulled the head to see if the head gasket seal is bad on that cylinder? Hope that's what it is.

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Oh boy that is some bad news, sounds like your going to be tearing down the power head. Pull the head off and see, I hope the piston doesn't have a hole in it. I'm sure the problem will present itself straight away. Be interested to see what you find and see a pic of the damage.

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

I will pull the head off this afternoon after I get off work. I assume it should be fairly clear what the issue is once I get inside. I'll post pics for sure.
I am curious though, assume it's just the head gasket seal which should be easy to fix, should I try to clean the piston heads etc? And if so, how?

This is the one part of my motor I haven't seen the inside of yet so I'm real curious to see whats going on.

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

If it is "just a gasket", what caused it to fail? Overheating caused by? Warped head now? May not be an easy fix, the last thing you want is to do all that work and replace parts to have the same happen again and then have to fix the cause. In your spare time maybe take your motor model number and check it for service bulletins that had to do with cooling or similar failures. You can decarb the heads with seafoam by spraying, soaking and a nylon brush. Bring the pistons TDC and do the same being very careful of the cylinder walls.

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

well I just finished pulling the heads. Seems part of the piston head failed. I did not see any scoring on the cylinder wall though I suppose any scoring would be "behind" the piston and therefore not visible to me. Here are the pictures

Before I pulled the head



You can see where the middle piston broke on the left hand side. (also what is all that crap around the seal?)


So at this point I'm not sure what to do. I would assume that I can buy a new piston from somewhere and put it in but I'm starting to get out of my knowledge zone. I am good mechanically but I really don't know what I'm getting myself in for. Any thoughts/advice

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Yeah she needs to be bored out and all 3 pistons replaced to do it right. You could try to pull it all the way down and remove just the bad piston and inspect the cylinder walls to be sure they are not only unscored but not egg shaped as well. You could get by then if it's all good by honing the glaze off the cylinder walls and putting in new a piston and rings. Check the bearings on the rod and replaced if scored up. If you get it that far down, may choose to replace all the rings and rod bearings.

If you decide to pull her the rest the way down, I have a tip that helps. I would take a sharpie to make a drawing of the power head on cardboard and then put all the caps and bolts on the drawing, including shoving the bolts through then putting the nuts on so you can put it all back together exactly the way it came apart and not mix up the pieces.

Looks like around $100 here at iboats for a new piston and rings.
Evinrude Inline Pistons - iboats

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

Thanks for all the help waterman

That a really good idea with the cardboard.

I probably will just replace all the pistons. (do it right and do it once)

My questions though:

1.Where do you get a cylinder bored out at? (I assume taken to someone)
2.I assume the piston I will be buying is either the .02 or .03 one to match the now slightly larger cylinder. Will the guy that bores the cylinders tell me which size I need based on how much he bored them out? Also if you bored them out to .03 is there a danger of weakening the cylinder wall?

Thanks

 

[clanton]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

There are 5/6 service bulletins that need to be done to this engine if you rebuild. Search this site for post that list the bulletins.
If you do not do the bulletins and prop engine to turn 6000 RPMS, middle cylinder will melt down again.

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

You would have to find a shop to do the boring. They would bore it out based on need .020 or .030 and let you know. I don't think it's a problem boring .030 over but that's it for those cylinders. The guy might say they don't even need to bore if there's no need.

That crap from the pic looks like corrosion in the water jackets to me. Is it soft and gooey or hard.

 

[ijmckenzie]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

It's hard and crusty. Your right, it is def corrosion in the water jacket. I don't know why I didn't think of that.

Watermann: Thanks for all your help man. I'm going to slowly start easing into this project. I have to travel for a month for work in June but I have July off so I'll prob start then. I'll def start a forum here and try to detail the process as I go through it...(see if I can help somebody else down the line). But seriously thanks for your time.

Clanton: I've looked around the forum boards and it seems like the service bulletins should be in the engine manual which I will buy. Also you were spot on about those engines having trouble with the #2 cylinder. Seems that the cooling system is less efficient at cooling the #2 cylinder and that they therefore have a tendency to overheat and break. I suspect that after 20 years of running the constant heating/cooling process became too much for the poor ol piston head. I did see some people talking about how you can fix the cooling issue w/ just a couple mods. Once again thanks for your time man; I really appreciate it.

 

[Chinewalker]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

I just rebuilt a 1989 version. Wasn't too bad a project. Total cost for parts was around $1000, including a used crankshaft, con-rod and block, gaskets, waterpump kit, thermostat bits, etc. I found used parts on eBay for the crank, rod and cylinder block (already bored .030 oversize). I did the cooling system updates while I had it apart. It was actually easier to rebuild than some older 70s as there are fewer gaskets, hence fewer machined surfaces to clean up.

 

[Watermann]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

It's hard and crusty. Your right, it is def corrosion in the water jacket. I don't know why I didn't think of that.

Watermann: Thanks for all your help man. I'm going to slowly start easing into this project. I have to travel for a month for work in June but I have July off so I'll prob start then. I'll def start a forum here and try to detail the process as I go through it...(see if I can help somebody else down the line). But seriously thanks for your time.

Clanton: I've looked around the forum boards and it seems like the service bulletins should be in the engine manual which I will buy. Also you were spot on about those engines having trouble with the #2 cylinder. Seems that the cooling system is less efficient at cooling the #2 cylinder and that they therefore have a tendency to overheat and break. I suspect that after 20 years of running the constant heating/cooling process became too much for the poor ol piston head. I did see some people talking about how you can fix the cooling issue w/ just a couple mods. Once again thanks for your time man; I really appreciate it.

Glad I could share some of my meager knowledge on engines. In our trouble shooting posts, #10 post I suggested checking the service bulletins for causes to address. It's nice to see you have focus and desire to get your boat back on the water. Some would just call her a basket case and move on. I look forward to seeing your rebuild thread!

 

[clanton]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

I did search, could not find the bulletins and probley not in the after market manuals. Bulletins also not in OEM manual. I am a ways from my J/E library, and will not be back until the middle of July.

 

[Davee3]

Re: 1992 Evinrude 2 stroke 70hp Can't get one cylinder to fire

I have identical problem with 60hp version Also looking for service bulletins I know one calls for relocating the water telltail to the upper corner of the water jacket cover - to eliminate air bubble collecting & cause of overheating. Another calls fro modified water pump . Two of us are fighting these issues at thread" 1992 Johnson 60 TLENE Stalling, Missing and General setup problems". Any more info on bulletins? Apparently boats that ride high & pontoons with limited lower unit in water are the main issues .

PS my pictures are on other thread - Middle cylinder no compression & sloppy in bore - broken ring? 2 cylinders have some scoring Crank turns smoothly so hope its OK hone or rebore?

There are 5/6 service bulletins that need to be done to this engine if you rebuild. Search this site for post that list the bulletins.
If you do not do the bulletins and prop engine to turn 6000 RPMS, middle cylinder will melt down again.