1995 Evinrude 90Hp V4 Low Compression on Cyl #3

[barryvj]

My boat troubles continue...

I took my runabout out for a sunset cruise Sat night with the family and the engine quit after a few minutes on plane. If it wasn't for the clanking noise I would have thought it was starved for gas. I tried to restart and the engine wouldn't turn. I took off the cover and the engine seemed very hot, but no buzzer sounded. After waiting a few minutes I restarted and limped in at just above idle (would stall at anything higher).

I performed a compression test with cyls 1, 2 & 4 all around 126 psi, but #3 was at 80 psi. I rechecked each cylinder after a heavy fogging and only #3 changed to 96 psi.

This is a 1995 E90TLEOR and I received verbal quotes for repair today at ~$4500. That's how much I paid for the boat and engine three years ago!

I'm thinking of getting a rebuild kit and doing it myself. I have the SELOC manual and read through the overhaul section. Except for a few special tools, it looks manageable.

Any advice for the procedure or a reference for the kit? Is there anything else I should do while I have it all apart?

I'm also looking at prices for a new 2-stroke, but they seem to be darn expensive.

Thanks.

 

[oldgradywhite]

Re: 1995 Evinrude 90Hp V4 Low Compression on Cyl #3

these old two stokes are simple and easy to rebuild. I would get a shop manual and make a project out of it. I will say if your crank shaft is bad it can get expencive quick.

 

[barryvj]

Re: 1995 Evinrude 90Hp V4 Low Compression on Cyl #3

I've got the engine apart following the manual. Things have been going well except for three broken bolts that I'll take care of later with easy outs and soaking in PB Blaster.

So this is what I found: #3 piston & cylinder scored heavily (see pics), #1 piston & cylinder scored lightly (?) (see pics). Pistons and cylinders 2 & 4 look fine. Note that both damaged pistons/cylinders were on the starboard side of the engine.

Some questions:

1. How do you make the decision to bring the cylinder to the shop and get it bored vs. honing it? My guess is that this cylinder is heading for the shop.
   
2. How do I know if the main bearings need to be replaced? The engine is a '95 and I think that this is the first time its been opened.
   
3. What would cause damage to only one side? Cooling? I checked the diverters and all plumbing with no problems/blockages noted. Originally I thought that I starved the engine of oil and still suspect that is the root cause. I'll be pre-mixing for a while until I gain confidence that the VRO2 fuel/oil pump is working.

I appreciate comments/insights.

Thanks.

 

[ezeke]

Re: 1995 Evinrude 90Hp V4 Low Compression on Cyl #3

You will want to have the scored cylinder bored so you might as well have the shop check the other cylinders and bore them if they need it. Wait until they tell you what size before ordering the replacement piston(s).

In most cases you save money by using a rebuild kit.

 

[barryvj]

Re: 1995 Evinrude 90Hp V4 Low Compression on Cyl #3

Update:

I ended up having the #3 cyl bored to +.030", the #1 honed within spec and the other two deglazed. My local machine shop was a great help, cost: $350 with the added removal of several stubborn broken bolts.

I used a Seloc manual that was confusing at times. They do not use consistent part names from one section to another and I overtorqued the top and bottom bearing covers because of this (and a lack of common sense). Thank god for Helicoils. I suggest getting an Evinrude manual along with the Seloc.

The trickiest part of the rebuild was assembling the rod end caps to the crank. I know they need to be exact and I took a few breaks because the alignment would change when I torqued them down. Finally go them right.

I replaced the thermostats, temperature switches, and water pump also. The starboard t-stat only opened at very high temperatures in my heated oil test, while the port side had failed in the open position. My starboard temp switch also did not trigger anywhere near the spec. I suspect that both of these issues led to the overheating of the starboard cylinders and caused the failures. To make things worse, some kind of insect built a nest in the buzzer alarm which completely disabled it (yeah...I should have known this when turning the ignition on...).

The water pump was in fine working order, but I replaced it anyways since you have to take it apart to inspect.

I took the boat out last weekend for the first time and everything worked great Running 25:1 oil in the tank and keeping the VRO2 on for now. Will go back to just the VRO2 after I confirm oil usage.

I've learned a lot with this project so if you are a newbie and plan to do a rebuild on an Evinrude of this vintage and have questions, drop me a note.

Stats:
Cost:
Machine shop: $350
Parts: $800
Timing & Synch at Marina: $150


My Labor:
Engine removal: 4 hours
Engine teardown: 3 hours (this is the easiest part)
Ordering parts: forever (local marina and boats.net)
Engine assembly and installation: 20 hours


Would I do it again? Yes, but over the winter.