resleeving evinrude

[canon]

I have a 91 evinrude 40 horse that has some a scorn # 2 cyclinder. The bill to get it fixed at a marine shop is over the worth of the motor. I talked to a machinist that can do the work at a 1/3 of the cost if I bring the head in. My question is, is that a difficult task and would I have to disassemble to crank shaft as well? I would think about boring it out but I think it is too far gone for that. It seemed like it happened all at once but it must of been going for awhile. I am thinking of premixing the gas/oil rather than using the oil injection. My concern is, if I do all this work, will the underlying problem be fixed or will it happen again. Any advice would be helpful.

[marine_man]

How mechanically and engine inclined are you? You're talking about a pretty major job, as the the cylinders are integral to the engine block, and not just bolted on like a snowmobile. So, yes, you're talking about the crankshaft as well.

The reason the machinist price is quite a bit cheaper is because there's not all the labor associated with almost completely tearing the engine apart.

Were you premixing before, or using the VRO pump? Do you know what the root cause was? Lack of oil? Overheat? Both? Neither?

marine_man

[gregg52]

i had 89 60hp evrinrude was great motor for bout 18 yrs then a cylinder went all at once like you i had guy rebuild the motor

for me

and he did take the oil injection out he said he could put it back but only last a yr or so

and he said the work he was doing would be good for bout 3 yrs or so and that about how long it lasted

the guy that did it up here is as honest as they come

and very good

it cost me 1200 and most of that was parts

[canon]

I do most of my own work on vehicles and have the tools, but I will say I don't know much about boat motors, but this project would definately help me learn. I was using the VRO pump. The marine shop I took it to thought that it just wore over time. If I do this project, I will make sure the carbs are in sync and no overheating issues. I personally have a hard time just tossing this motor out and buying another used one, but I have looked at all options. I suspect it had something to do with the VRO but not sure. I am excited to work on it, but I don't want to underestimate the work involved. I was hoping that I didn't have to pull the crankshaft, the book I have doesn't show it very well. I think I will take pics of every step along the way.

[DTro]

Don't know if this appllies to the 40hp or not, but I had a 70 that had the same demise. I had it bored out/oversized pistons.

The mechanic mentioned that there was a recall/service bulletin about a cooling line that had to be rerouted so that it cooled more efficiently.

I also disconnected VRO and premixed. I sold the boat and happened to run into the guy a while back, still was going strong after about 5 or 6 years.

[boatfixer]

Usually, usually , 1 scorded cylinder with a multiple carbed engine indicates a problem with a carburator. Most of the time when the vro goes, you will find bearings as well as cylinders shot (obviously the vro supplies the entire system with the mix, each carb is takes it from there). You'll find out more when you tear it down, which by the way is not very hard at all if you are fairly mechanical.

Piston melted/aluminum stuck to cyl wall= Excessive heat, either lack of lube or poor cooling

Piston burned off the side towards exhaust port=air leak

Hole in piston= Pre ignition from a timing issue or poor fuel

Broken rings, etc=fatigue; could be lack of lube as well

None of this is the end all be all, but may give some insight as to what happened

[canon]

Thanks for the info, any info at this point really helps. In fixing the cylinder, I have to also find the cause of why it happened so it doesn't happen again. One thing that someone told me is if the bottom cylinder is scored, then it could possibly be a crank seal issue. I just hope I know what I'm looking for once I get in there. I am actually kind of excited about this project but I do understand I need to do it right.

[boatfixer]

I'd also like to add, when you do this project, be sure to rebuild the carbs and put in a new water pump.

[canon]

Thanks boatfixer for all of the info. You know tonight was looking at the motor getting a game plan, tools, baggies, digital camera, ect. and I noticed a lot of gas/oil below the carbs on the plastic casing. Is the inside wet with gas/oil on all 2 cyl motors? Is that just what happens? I just wondered if maybe the excess gas maybe due to a carb problem, or at least a symptom. I am thinking carbs or crank seals right now, but I will learn more tomorrow morning when I start the tear down process. Again, any advice is always appreciated.

[boatfixer]

Often when you tilt the motor up, some of the gas run out the float bowl vents. Not sure if thats the case here, or you may be on to something?

[canon]

Not to thicken the pot here but when the motor is in the fully down position, I now have gear oil comming out of the prop. I know it is not related to the other problem, however it is funny how things happen at once. I never had this issue before, I wonder if it happen in transport to the marine shop and back. The motor is giving me every reason to toss it out, but oh well, I think it is all fixable. The boat did fall back in the driveway the other day, so maybe it knocked something around near the prop.

[Tom7227]

Canon,

I have nothing technical to add to this but after reading the thread my thought is take it apart and if it's toast at least you've learned a lot about what's in there and with the help from this thread you may learn what the cause is once you do the CSI on it. What the heck, the weather's lousy, you can't use the boat for probably another couple weeks, not much else to do. This is a learning experience, and if you share your progress on this HSOforum others can learn as well. If you go for it the pics may help others confirm your conclusions.

Go for it.

Tom

[marine_man]

Not to thicken the pot here but when the motor is in the fully down position, I now have gear oil comming out of the prop.

Are you sure it's lower unit lube? It could be unburnt gas / oil / fogging fluid that's leaking out of the prop, especially if it's got a black color to it.

marine_man

[canon]

I am not sure, it looks like the fluid is comming from the o ring seal behind the prop, the oil is running down the skeg. I took off the bolt holding the prop on and it didn't seem very tight so that may of been the problem. The other issue is when I took off the prop, I noticed some metal shavings in the prop and body it connects to. So I am not sure what is all going on, I have been surfing sites lately looking for other motors.

[marine_man]

What color is it, and what does it smell like?

Based on your new information it doesn't sound good, but to be sure, it's worth checking. Also, the nut that holds the prop on doesn't do anything with respect to sealing the lower unit.

marine_man