250R crack in sleeve

[sikadelic]

i have an 88 R with a 1.5 over piston . there is a small horizontal crack in the sleeve between the the two main exhaust ports. what could have caused this? how bad of a problem is it? i will post pics soon

[headache]

heat is the cause of this. Sometimes if a motor is ported and the bridge is too thin it will cause a crack. If i port a bridged exhaust i never make it any thinner than stock. Oh and i wouldn't try to run it again. your going to need to sleeve it or buy another jug.

[SuperSherman]

I have a cylinder that I've been running hard on an outlaw kart for years now that has a cracked exhaust bridge. I got it for nothing and just used a rubber abrasive wheel and relieved the area around the crack a few more thousandths and it's been running strong for me. Same with the intakes on this thing, just relieved less.

[headache]

dang sherman your brave lol. I wondered if that would work, i honestly didn't think it would. Glad to hear you lucked out!!

[Honda 250r 001]

Originally posted by headache
dang sherman your brave lol. I wondered if that would work, i honestly didn't think it would. Glad to hear you lucked out!!

hell ya i wouldnt take the chance. you could also cut the exhaust bridge out couldnt you? like on aftermarket cylinders, but it would eat rings faster.

[machwon]

I've also used them with cracked bridges and exhaust side skirts cracked. Relieve the crack on the bridge nicely and it will work fine. They do tend to eat rings a little faster and also shortens the bore life each time. Otherwise they work fine.

[deathman53]

I have a ported 88 cylinder with a cracked intake bridge, I was told not to use it. Its ashame, its a sparks ported cylinder.