cracked cylinder sleeve w/ pics...

[jcs003]

her is the damage i was telling some about.

[jcs003]

2

[HondaATC500X]

That must have happened from someone dropping the cylinder and that bottom ear hitting first or something. I highly doubt that happened during the course of the engine running.

[jcs003]

Originally posted by HondaATC500X
That must have happened from someone dropping the cylinder and that bottom ear hitting first or something. I highly doubt that happened during the course of the engine running.

it didnt have a crack when i reassembled it after the port work.

[quadrcr161]

Originally posted by HondaATC500X
That must have happened from someone dropping the cylinder and that bottom ear hitting first or something. I highly doubt that happened during the course of the engine running.

i can post pictures of one that failed like that, took out the crank, cool head, and cases as the skirt material was shoved through them by the crank.

be glad you found it in time. mine gave no warning signs, was running strong, was freshened up 1/2 through a season and let go during the winter at a quad wars event, off idle.

[86 Quad R]

did you by chance have a worn counter balancer at some point with a loose piston slap?

[jcs003]

Originally posted by 86 Quad R
did you by chance have a worn counter balancer at some point with a loose piston slap?

counter balancer is good. the actual first indicator(didnt know at the time) was a strange ringing/buzzing sound. i thought it was the kick mechanism. i discovered it when the base gasket failed and went to replace it.

[HondaATC500X]

I have had 4 250Rs for about 10 years now and thats the first I've ever heard of this happening. Learn something new everyday!

[86 Quad R]

Originally posted by HondaATC500X
I have had 4 250Rs for about 10 years now and thats the first I've ever heard of this happening. Learn something new everyday!


here as well and i have pulled some engines down that had soo much piston slap that it was like comparing a bb bouncing around in a box car. :eek2:

[quadrcr161]

this happened back in 2000, ive had my 1st R since 1992.

didnt load the pic, brb ill try to get something posted

edit again, lets see if this works, sometimes it dosent.
http://im1.shutterfly.com/media/47a0d934b3127ccefaca737b384400000030O02QZuGTRoyZA9 vPhI/cC/f%3D0/ps%3D50/r%3D0/rx%3D720/ry%3D480/

[quadrcr161]

trying this again, sorry

[quadrcr161]

Head damage

[jcs003]

Originally posted by 86 Quad R
here as well and i have pulled some engines down that had soo much piston slap that it was like comparing a bb bouncing around in a box car. :eek2:

the crank was in spec and the wear(piston/bore) wasnt extreme.

my other thought on the subject is: the blown gasket sucked in extra air concentrating on that area of the sleeve. this then created a hot spot which created a vulnerable section on the sleeve. with this stated i was stuck at one time in the woods and revved it to peak to get it moving again, and my conclusion is this is the result.

note: this is the exhaust side of the pics dont show.

[fearlessfred]

Originally posted by HondaATC500X
That must have happened from someone dropping the cylinder and that bottom ear hitting first or something. I highly doubt that happened during the course of the engine running.
i would have to agree. i have been riding and wrenching on 250rs since 85 and have not seen this on stock sleeves,but have heard of it on over sized big bores.the other cylinder shown looks like the porting could have caused the prob. to much removed from intake and transfer next to it but is hard to tell for sure from that pic.and it looks like it was on its last bore ( how thin the sleeve is)