burned out piston

[hfthe3rd]

does anyone have a picture of what a burned or fried top end looks like.. im trying to figure out if my pistons are ok after my motor ran pretty hot in the water last week. I still cant figure out why it ran so hot because I blew all my cooling lines out and nothing came out of them. And as of right now i need new o rings for my r&d head because the ones on there melted, and the ski isnt starting. I hope becuase of the orings melting.

the skis a 750 sx

 

[OCD Solutions]

Let's just say anything that even remotely looks like this, is not a good thing.

This is a failure where too much heat caused the rings to expand into the exhaust port and caught, breaking off a bit of the piston. You should be looking for scoring on the sides of the piston, balled up aluminum binding the rings.

If it's a light seizure you may get away with just honing the cylinder, replacing the rings and cleaning up the pistons carefully. A medium seizure would mean honing and replacing the pistons and rings, and a hard seizure means boring and replacing the pistons.

Let's hope it's nothing major and post pics up when you get it apart. Keep in mind as you tear things apart that you are looking for clues to the failure in the first place.

 

[Maxumflux]

Let's just say anything that even remotely looks like this, is not a good thing.

This is a failure where too much heat caused the rings to expand into the exhaust port and caught, breaking off a bit of the piston. You should be looking for scoring on the sides of the piston, balled up aluminum binding the rings.

If it's a light seizure you may get away with just honing the cylinder, replacing the rings and cleaning up the pistons carefully. A medium seizure would mean honing and replacing the pistons and rings, and a hard seizure means boring and replacing the pistons.

Let's hope it's nothing major and post pics up when you get it apart. Keep in mind as you tear things apart that you are looking for clues to the failure in the first place.

damn that sucks. did you get a mussel in your cooling?:squint:

 

[ger87410]

Is it cranking?

U could check compression to see if it's blown.

 

[hfthe3rd]

Is it cranking?

U could check compression to see if it's blown.

yes and i need to find a compression tester once i get my o rings in.
it does seem its still strong just from the feel..


and ya my pistons just from the top few deffintly dont look anything like that.

 

[Waternut]

Well I've overheated my 750 with wiseco pistons to the point that it shut down because the head gasket blew and I'm still running strong on it. If the o-rings melted, you probably don't have a seal on the cylinder and can't get any pressure and therefore can't get combustion.

I've blown out my cooling lines lots of times...sometimes it sounds like you blew something out and sometimes it doesn't. As long as you're blowing them out in the opposite direction of the flow, you should be good. Just monitor it afterwards because it is possible to get a rock wedged into a 90° fitting.

 

[SUPERTUNE]

Tip of the day...Always use water pressure to check flow for cooling problems.
You can visually see restrictions with a water flow check, whereas a blow air check will only tell completely clogged line or passage, but no partial clog.

Example: Old Kawasaki's always have collapsed cooling lines (restricted) where they run through the hull from the pump and cause these exact problems your describing.

 

[Waternut]

Tip of the day...Always use water pressure to check flow for cooling problems.
You can visually see restrictions with a water flow check, whereas a blow air check will only tell completely clogged line or passage, but no partial clog.

How much does that cost and where can you get one?

 

[SUPERTUNE]

Just use a hose adapter from a flush kit...Less than $10 bucks.
Also get a shut off to put on the end of the hose first from any hardware, Home Depot, or Lowe's store.