Sleds won't start. Now the engine is down on compression!

[LazyBastard]

If a valve is stuck a "little" open, then within 2 revolutions, it will be pushed FULLY open, then slide back in. If it didn't slide back in, then it would be PUSHED back in by the piston. Within about 10 revolutions, it would DEFINITELY be COMPLETELY loose. Valve did NOT stick in either of those engines.

 

[Iceman57]

The valve could be open 1mm and not hit the piston. There is no way the piston comes close to within 1mm of the top of the piston. As he stated there was carbon built up in the head and that could have been enough to not let the valve fully close.

 

[Skydog]

Na bad gage seen it tons of times gages all over the place.

Batterys are fine, fuel pump relay is fine, they spin over like there is no compression. this is happening to both sleds!

That happened before they were even taken in to the dealer, doubt it was a bad guage!!!!!!!! :ORC

Was a guage put on to see there was no compression? Or are we going by (they sound like??)

 

[CaptCaper]

I worked at a Yamaha Outboard Dealer on the Cape and he put ring free in the undergound tanks.. He rented slips and sold gas there. So you didn't have a choice you had to pay for RingFree..Most there had Yamahas.

These Japenesse must machine close tolerences.. I just bought a new Juki Industrial Machine and it was siezing up.. It is self lubercating and still seized. The mechanic told me to go slow for a month but I opened it up and oiled the #*$&@ out of it. It' s now quieter and I can run it normally.
It will break in after awhle but I will oil like all my other machines in the past. By hand.. When it gets noisy again. I'll oil it.

Anyway I think I'll keep running ring free in my 07 Attak for awhile after reading this stuff.

His problem may not be carbon build up just a fuel issue. I can't seem to find where he spelled out exactly what the tech did or didn't do to call the problem.

 

[LazyBastard]

The valve could be open 1mm and not hit the piston. There is no way the piston comes close to within 1mm of the top of the piston. As he stated there was carbon built up in the head and that could have been enough to not let the valve fully close.

You're missing the point. A 4-stroke engine has CAMS that PUSH the valves out. If its stuck 1mm out, then it won't be there for more than 2 revolutions until the CAM pushes it out FURTHER.

 

[Skydog]

Yep yep

 

[Iceman57]

I'm out at the GM Milford Michigan proving grounds several times a week surrounded by 4 stroke engines with all kinds of problems. I have seen engines that had valves that wouldn’t close all the way due to bad valve guides, slightly warped valve stems, burned exhaust valves, cracked or stressed valve spring to carbon build-up around the valve seats as well as high olefin content in gasoline coating the valve stem. Please don’t try to give me a lesson on engines. I am aware of the cams and valve springs but if there was a build-up on the valve shaft at the end or there was carbon build-up around the valve seat the valve could be held open just enough not to seat properly.

 

[LazyBastard]

Carbon doesn't build up when the engine isn't running. And if something is bent, ringfree sure won't straighten it.

Oh, and if you guys at gm testing grounds and engineering new what you were doing, then my gm truck wouldn't be such a POS and a gas guzzler.

 

[Iceman57]

If a valve is stuck a "little" open, then within 2 revolutions, it will be pushed FULLY open, then slide back in. If it didn't slide back in, then it would be PUSHED back in by the piston. Within about 10 revolutions, it would DEFINITELY be COMPLETELY loose. Valve did NOT stick in either of those engines.

Carbon doesn't build up when the engine isn't running. And if something is bent, ringfree sure won't straighten it.

Oh, and if you guys at gm testing grounds and engineering new what you were doing, then my gm truck wouldn't be such a POS and a gas guzzler.

First you’re saying that a valve couldn’t be stuck open. Then your insinuating that ringfree solved the problem which would indicate a stuck valve..........hello which is it? :ORC And I just posted findings of stuck valves that I have seen in the past. I'm not telling you that any one of those scenarios was the cause of this problem. But I can see how you would know what happened to that engine after tearing it apart. Any F.Y.I…..a valve can be stuck partially open and not be struck by the piston during its power or exhaust stroke! What’s with the POS comment.....why do you always get your panties all knotted up, it just a posting dude. I've had my share of problems with my Apex and it gets about 11 MPG but you dont see me calling Yamaha a POS and a gas guzzler.

 

[LazyBastard]

Please learn how to read before you post again. You seem to have a difficult time following the logical progression of words.

 

[LazyBastard]

And just in case there is the SMALLEST possibility of you understanding, I'll try AGAIN to get through to you.

I *NEVER* said that ringfree fixed anything - I said that it DID NOT fix anything. I suggest that the whole ringfree argument is ABSURD. I also *NEVER* said that a valve stuck, in fact, I said SPECIFICALLY that a valve NEVER stuck. YOU are the one suggesting that it was a stuck valve and I DISAGREE WITH YOU.

I have seen ... {blah blah blah blah} ... carbon build-up around the valve seats

The reason I mentioned ringfree is to CONTRADICT EVERY POSSIBILITY that you have presented in order to CONVINCE you that no valves were ever stuck on those engines.

 

[Iceman57]

I said SPECIFICALLY that a valve NEVER stuck. And I know because I was there and peaked inside the engine.

Also, if the valves get stuck open, the pistons will actually HIT them, which would do one of two things;

a) eventually work the valves loose,
b) cause damage to the valves and pistons - this would be a HUGE major rebuild and would cost thousands.

And incase you've never worked on a 4 stroke engine....especially a head......a valve could be stuck open and not hit the piston. Your either unexperienced with 4 strokes or in denial.

And how do you know a valve never stuck? did you work in the sled. Did you use your crystal ball to look inside the engine. I'm saying its POSSIBLE that a valve stuck, your denying that could ever happen.

Valve stuck open......but wait that could never happen

 

[LazyBastard]

I am CERTAINLY denying that it could happen SIMULTANEOUSLY on ALL the cylinders on TWO engines, AND magically they could ALL free up, ALSO simultaneously, by pouring SNAKE OIL into the engine.

You seem to be the one lacking experience.

 

[Travis Moore]

I'd recheck the compression with a diffrent tester or do a leakdown test.

T

 

[**sj**]

guy's....let's not attak each other (sorry couldnt resist) the purpose is to help the guy who has the problem not to prove someones possible solution wrong....
you both have been very helpful in the past to many...