Maximum 250r bore?

[mdl76]

What is the Max you can bore a 250r cylinder without having to resleve? it looks like wiseco sells a 69.5mm piston. A gentleman on this site has a cylinder for sale and he thinks it has a 68mm bore right now, but needs to be bored again. I just dont want to buy a cylinder to find i need a new sleeve for it to. thanks

[zedicus00]

68mm if you r running a 87-89 piston. 69.5 if you are running a 85-86 piston (and can find sumwhere that sells it, 68.5 is largest easy to find piston) you can run an 86 piston on a later setup with a 4.5mm spacer plate.

[mdl76]

thanks for the reply!
so it sounds like with a 68mm bore, i can only do one more bore job and then ill need a new sleve. is that right? are sleve exspencive?

[zedicus00]

1 more bore easily. sleeves arent too expensive but having it put in will prolly cost more then the sleeve. and if yur gettin a jug resleeved anyways that is the time to think about having a big bore put it. its not much more expensive.

[Rich250RRacer]

I'd like some other opinions on this. I've never had good luck with resleeved cylinders, they always seem to run extremely hot, shortening ring life. I'm talkin 1 month's time, and yes the air filter is always clean and oiled.

[xlr810]

I've got a cylinder that I was considering resleeving as well. I hadn't heard about them overheating.

Didn't Ballance run a Honda cylinder with an LRD 300 resleeve?

[Eddiesanders250]

how much to bore it out like .80 over stock??

[mdl76]

to bore 80 over, is that .080 inch?

does the lrd 300 resleeve increase the cc's by cylinder dia. only or is the stroke also increased?

so you can still use a cylinder, to put a big bore in it, after their are no bores left in the sleeve? so if i buy a cylinder right now for a decent price, I just want to be sure im not tossing my money away. thanks all.

[xlr810]

A cylinder that is 80 thousandths over (8th overbore, 68mm) still has plenty of life left in it. Should be able to go to 12 bores over, if each bore has been straight in the cylinder. However, you will only be able to find 1986 style pistons larger than 68mm. The 86 pistons are a drop in item if you have the short rod 86 crank. If you have the long rod 87-89 crank, then you will need a 4.5 mm spacer plate, 2 base gaskets, and longer cylinder studs.
261 will be your actual displacement unless you have a stroker crank. It is not a bad cylinder to purchase if the price is reasonable, and the port work matches the setup you are looking for.

I'm not sure on the LRD setup. Would be worth calling them if you decide to go that route.

[zedicus00]

big bore kits as well as stock size sleeve kits both require new sleeves to be put in and are both options for when you run out of bores in a stock cylender. ive never had a problem with a resleeve overheating at all. also theres only a tiny cost difference between the bigbore and stock bore sleeves. the added cost comes in when they go to put a bigbore sleeve in they hav to bore the jug out a ways too. but even then theres not much of a cost difference. ive ran both resleeve stockbores and resleeve bigbores with no problems.

[mdl76]

I heard a second on the 120 for over bore, so it looks like ill be able to get about 4 more bores out of a 80 over sleeve.

[zedicus00]

yup, but like i said not everyone sells thouse pistons... maybe you can order right from wiseco... and the only reason a resleeved jug would run hot is if it was done wrong so dont worry about getting it resleeved when it needs it... look up eric gorr he does awsome work and is a good price.