Worn Cam?

FE,

The engine was FULL of water after I submerged it, so it didn't run at all until I drained the oil, pulled the carb, removed the exhaust, suctioned out the cylinder. It was a damn mess...

I drained the oil right when I got home, filled it with some cheap car oil, ran it for about 10 seconds and dumped it again. After that I ran it for like 20 seconds, dumped, 60 seconds, dumped and probably once more. I was less concerned about the water than the dirt that was in the engine.

Anyways, that was only my 2nd or 3rd ride so I don't have any baseline to go on, but I suspect the bike has likely been wearing like this for a while.

I looked at the starter clutch and couldn't see any signs of trauma, but I couldn't actually spot any shim in there. It turned freely and smoothly though so it didn't seem like the source of the problems. Does that sound right?

Once I track down a flywheel puller and make a case splitter I'll have a better look at the internals. The engine is out now...

Thanks for the help, guys.

I'm back into the engine and the starter clutch seems OK to me. I can't see any shims in there, am I looking at the wrong part?

Anyways, everything was clean and there were no jagged bits, so not the source of the metal bits/paste. There is a bit of drag when spinning the inner and outer hub against eachother.

For the cam try a bit of a polish with 400 or 600 wet and dry paper in the direction of rotation, nothing to loose if you think it is stuffed anyway, I cant really tell from the photo with the oil on the surface.

Well I finally got the engine open. It's been a busy week with Easter dinners, driving around to get the flywheel removed, making up a case splitter and having some idiot crash into my parked truck in front of my house and totalling it...

Anyways, I think I found a problem:


The oil control ring is broken into several pieces. The cylinder is scored a bit so it will need to be repaired. I'm not sure about the piston, the ring lands seems OK so I'm not sure if it's reusable. The skirts have some light scoring, but the wear seems light.

Cylinder. The scratch on the right side is the deepest and can easily be felt. The deposits on the piston make me thing some oil was getting through.


Case Splitter:


Questions:

The OEM cylinder liner might be cheaper than getting this one repaired. The local shop (Mongoose) charges $325 to repair and nikasil.

-Can anyone recommend a place to get this repaired? I don't mind putting it in a box and mailing it off to save some $$

-Is the new liner (#81530005000) ready to use, or does it need to be plated?

-Did the broken ring cause the scoring in the cylinder, or did something else get in there and f*&k things up (mud/dirt)?

-The cylinder still has nice cross-hatching. Does it look like it has 357 hours on it or was it replaced not too long ago? Some parts looks surprisingly clean, other look old and tired.

-This should account for flaky bits in the oil plus excess metal paste on the magnet, right???

I'm tired, I'll post more pics tomorrow with more questions. Thanks.

-Kent

I would think the piston has had it. we need a photo of the two thrust faces to help with that decision though....

yes you need to re-nikasil. try Langcourts in Auburn, Texas?

yes, new liners come ready to go

regards

Taffy

Sorry to hear about the truck... that sucks.

-http://www.cvtech-aab.com/en/ These dudes do re-lining, quoted me at $250 yesterday.
-Haven't checked out the place taffy recommends, will do now... Mongoose seems to be directly affiliated with Langcourts

KentJ said:

The oil control ring is broken into several pieces. The cylinder is scored a bit so it will need to be repaired. I'm not sure about the piston, the ring lands seems OK so I'm not sure if it's reusable. The skirts have some light scoring, but the wear seems light.

Questions:

The OEM cylinder liner might be cheaper than getting this one repaired. The local shop (Mongoose) charges $325 to repair and nikasil.

-Can anyone recommend a place to get this repaired? I don't mind putting it in a box and mailing it off to save some $$

-Is the new liner (#81530005000) ready to use, or does it need to be plated?

-Did the broken ring cause the scoring in the cylinder, or did something else get in there and f*&k things up (mud/dirt)?

-The cylinder still has nice cross-hatching. Does it look like it has 357 hours on it or was it replaced not too long ago? Some parts looks surprisingly clean, other look old and tired.

-This should account for flaky bits in the oil plus excess metal paste on the magnet, right???

I'm tired, I'll post more pics tomorrow with more questions. Thanks.

-Kent

Click to expand...

Check the piston, you my find what made the score still embedded, possibly
just above the top ring groove from the looks of the bore.

Could get away with just new rings if the piston ring grooves are not damaged.

Here are the thrust faces:

Front (major or minor thrust? Unsure which way the crank spins...):


Rear:



Some stuff:


I don't know why or when the ring broke, but I'm sure it caused SOME of the scoring in the cylinder. The deepest one (near the right side wrist pin) lines up with the piece of metal in the above photo and starts below the top of the piston's reach.

The other scoring on the liner starts above the piston so it was probably introduced through the combustion chamber. I'm thinking that a piece of dirt got in there (possibly, but big pieces shouldn't go through the air filter) or more likely a big chunk of carbon dislodged when it got wet. As you can see in the 3rd pic there was dirt/carbon under the ring in the ring gap.

Probably unrelated, but the liner had a small chunk taken out of it at the very bottom. Not in the cylinder bore, but just at the bottom of the casting. If that fell into the engine it could cause problems but maybe it was banged up when someone else had the liner out before?

I'll try to take the piston to my machinist this week for his opinion, but I suspect I know what everyone's advice will be.

The damage is done now, but I'm just hoping I can pretend that the engine was wearing like this for a while and I didn't f*&k it up this badly on my 3rd ride out...

Thanks!

use that piston again. it'll be OK. good infact.

Taffy said:

use that piston again. it'll be OK. good infact.

Click to expand...

I agree. It doesn't look too bad. Maybe take some fine sandpaper to it. Ensure no high spots.

Look at third photo from first post maybe the sims between the bearings are bad looks like only half are their ? I can't tell.

Taffy said:

use that piston again. it'll be OK. good infact.

Click to expand...

Good? Great! I'll put that $250 back in my wallet for now. I might come out of this relatively unscathed and maybe a little smarter.

I'll go over the piston and make sure there aren't any cracks/chips/deformations etc before I check that one off the list.

If a new liner is available from Munn then that might be the cheapest route, especially if I can find another 25% off sale. It might be quicker too, it sounds like 3 week turnaround on Nikasil should be expected.

No concerns about running a new liner with a used piston?

Rainerio said:

Look at third photo from first post maybe the sims between the bearings are bad looks like only half are their ? I can't tell.

Click to expand...

Rainerio, do you mean the 3rd photo from page 3 (engine case), or from 1st post on page 1 (cam followers)?

First page third photo it looks to Me that the shims are half mooned. Cam followers

25 years ago I drowned My 400 Husqvarna two stroke it went a 100 meters under water fast running water. Only bad thing to it was both foot pegs got rip off. After removing water from the tank and engine. left water in gearbox till I got back. 4 kicks to start it. Haven't had a problem with it only in last 5 years it's hard to kick start but it bump starts EZ. Will be looking at that and still have it. So I'd like to know after your Bikes all good what would you do if some ones 4 stroke drowned ?

Rainerio said:

25 years ago I drowned My 400 Husqvarna two stroke it went a 100 meters under water fast running water. Only bad thing to it was both foot pegs got rip off. After removing water from the tank and engine. left water in gearbox till I got back. 4 kicks to start it. Haven't had a problem with it only in last 5 years it's hard to kick start but it bump starts EZ. Will be looking at that and still have it. So I'd like to know after your Bikes all good what would you do if some ones 4 stroke drowned ?

Click to expand...

Sorry but how did it go 100m under water and you recover it?

It hit a rock and some one saw the handle bar if wasn't for that I would of come back later when the water went down (I got lucky) I tided a rope around Me had a friend holed on to it at that point water was only .75 of a meter deep maybe 4 meters from the waters edge at that point water wasn't to bad. Didn't get all the water out of the tank bike would run funny off and on but OK. No problems after all that.

Rainerio said:

25 years ago I drowned My 400 Husqvarna two stroke it went a 100 meters under water fast running water. Only bad thing to it was both foot pegs got rip off. After removing water from the tank and engine. left water in gearbox till I got back. 4 kicks to start it. Haven't had a problem with it only in last 5 years it's hard to kick start but it bump starts EZ. Will be looking at that and still have it. So I'd like to know after your Bikes all good what would you do if some ones 4 stroke drowned ?

Click to expand...

I'm no pro, but I'd drain the water as best you can and change the oil till it's clean. After that, ride it like a dirt bike and keep an eye on things. Like I say, I don't think the water did much damage. The mud that got in might have hurt something but I'm suspecting the previous owner was seeing some metal on the magnet before he sold it (pretty cheaply).

KentJ said:

Good? Great! I'll put that $250 back in my wallet for now. I might come out of this relatively unscathed and maybe a little smarter.

I'll go over the piston and make sure there aren't any cracks/chips/deformations etc before I check that one off the list.

If a new liner is available from Munn then that might be the cheapest route, especially if I can find another 25% off sale. It might be quicker too, it sounds like 3 week turnaround on Nikasil should be expected.

No concerns about running a new liner with a used piston?



Rainerio, do you mean the 3rd photo from page 3 (engine case), or from 1st post on page 1 (cam followers)?

Click to expand...

Kentj,

Have you ever tried Mongoose Machine in Poco? You are in Vancouver correct? I have been using them for 30 plus years and always good service. Also thinking that piston?? I never use any piston that has damage or welded debris on it lol, Want another score in the new liner that would be the way unless you machine it to spec

I don't think he's stupid enough to re fit it with the debris still in it?

jesus H

Taffy

This place in is Toronto... they say $200 to re-nikasil.

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