blew the port engine while offshore
- Thread starter lime4x4
- Start date
Thanks that's like a 10 hour road trip one way for me for an engine that has low compression on one cylinder
I think the piston will clean up...lol Links outboard in Delaware can either bore the cylinder or install a new sleeve
Wow! That's worse than mine was/is. The sides of my piston are pretty much intact. It's just the top that is chewed up.
John, just out of curiosity (more for my own knowledge in case I decide to have the cylinder fixed), did Beav end up saying he couldn't (wouldn't) do it?
When i called i was told they didn't really have the equipment or specs for outboards. If u rebore the cylinder then the ports need to be beveled. Links outboard gets 50 bucks for a rebore or a couple hundrend to install a new sleeve. Beav did say they probably could probably hone the cylinder. I'm beyond a simple hone job..lol
Dennis I found a machine shop in lehighton/weissport that works on 2 stroke engines. Just dropped the block off today. Around 120 to bore the bad cylinder out 0.020" and hone the other 5 cylinders
$120 sounds like a pretty fair deal! From the little bit of research that I had done a few months ago, it seemed like the +.020 pistons Yamaha pistons were relatively easy to get... I think about $100? Does that sound right? You tore the block down completely before dropping it off? I'll keep my fingers crossed for you that .020 is all you need. That's too bad about Beav's as that's a different answer he gave me - strange because he even said he works on 2-stroke sleds and I think he even said he's done a few outboards. But, that place is even better since it's right there in your neck of the woods!
I just dropped off the bare block. I've found 0.020 and 0.040 pistons on ebay for 55 bucks and that includes the rings,piston pin and clips
Since i can reuse all my bearings and the 5 other pistons i'll have about 1K in the motor with machine work. Which is way cheaper then a new powerhead. so far the hardest part about the whole process was getting the powerhead off the midsection. Almost 30 years of being in saltwater the bolts that held the powerhead on were corroded fast. 3 of them actually broke and i had to take a cut wheel to the midsection to cut the bolts off. I'll either slicone the cuts shut or apply some jb weld to the cuts.
Also i was torn on having the other cylinders honed. The engine only has 572 hours on it. The cylinders didn't look bad. Some very slight wear marks and what appeared to be rust but the cylinders were smooth. So that means getting new rings for the 5 other cylinders
lime4x4 said:
Cool - that's even better. I didn't even think of checking eBay - but admittedly, I haven't bought (for no other reason than I usually don't think about it) much of anything from there.
lime4x4 said:
Well, if it was me I would probably think to myself "While I've already got everything torn apart, it makes sense to spend a little more now..."
I agree 100% it makes sense but at the same time i never found a reason the cylinder failed. I checked the oil pump and hose and injector and that was fine. Tore the carb apart found no dirt and the jet was open. After looking at the service manual on how to put the engine back together. The oil pump isn't timed to the crank shaft. So basically it injects oil once every revolution. Which would allow a constant supply of fuel/oil mix around the crankshaft and rods and the cylinder sleeves. Some people say to convert to premix but i don't really care for that. One it would have to be a constant high ratio of oil to gas for the engine not to seize up in the higher rpm's. Then at low rpm's it would be too much oil/gas ratio and plugs would start to foul and it will probably smoke real bad. From what i researched the yamaha oil injection system for that year is pretty much fool proof. The engines hardly smoked at all i just passed that off as the newer 2-stroke oil is much better then from the 80"s. It's just gonna be long winter of waiting. I should have the engine put back together towards the end of october early november. Then i'll have to wait till spring to test it out. Now that i have my engine all tore apart and c how everything works it really is amazing on how these engines survive with just a little bit of oil/gas mixture actually making contact with the bearings and cylinder sleeves.
You mentioned that you never used an additive like Ring Free. That is most likely the cause of the ring failure. Carbon builds up in the ring slots and that causes the ring to either twist or stick. That leads to ring breakage and then what you saw is what happens when a ring breaks.lime4x4 said:
Doc Stressor
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Got the block back cylinder #3 is all cleaned up and bored .020" over had the shop also rehone the other cylinders as well just to clean them up a little
Doc Stressor
Well-Known Member
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- Seafarer
Doc Stressor said:
Yes, where are the cross hatches to help seat the rings? Also look shiny.
Maybe it is just camera and lighting?
I think it's just the camera angle. The shop claims to have done alot of 2 stroke outboard blocks..