jimbob Posted December 18, 2008 Report Posted December 18, 2008 (edited) ok so im in the middle of a bit of a "revamp" on my shee and ive took the motor out to give it a good clean and a paint and some power upgrades. whilst its out i thought id check the liners and pistons for any obvious wear or scoring and bore sizes. as luck would have it the liners seem to be in very good shape and so do the piston crowns and it hasnt been bored as the liners both read 64.16mm , one of the domes has some pitting but thats not an issue as the head is getting changed for a cool head. ANYWAY ive wound the engine round to half stroke so both pistons meet in the middle and ive given them a bit of a wiggle from front to back-side to side to check for play. SO the question is how much play should i expect? none? 1/4mm-1/2mm? Edited December 18, 2008 by jimbob Quote
Paddleboy Posted December 18, 2008 Report Posted December 18, 2008 none. if there is sideway movement that is trouble Quote
jimbob Posted December 19, 2008 Author Report Posted December 19, 2008 so if my liners are ok could i get away with just buying an 0.20 piston set and not bother with the rebore? Quote
Paddleboy Posted December 19, 2008 Report Posted December 19, 2008 check it to make sure the cylinder isnt out of round to determain if you need a bore if it all checks out Quote
jimbob Posted December 19, 2008 Author Report Posted December 19, 2008 cool so if its round then its just the next size up pistons ? Quote
Wildcardracing Posted December 19, 2008 Report Posted December 19, 2008 Ideal piston to bore clearance is .003 to .0035 inches with a set of Wiseco pistons, you may not need to rebore...you may be able to get away with a clenup hone and new pistons. Quote
firebanshee Posted December 19, 2008 Report Posted December 19, 2008 cool so if its round then its just the next size up pistons ? You CAN'T go up to the next piston size without getting it bored.You could by the SAME SIZE piston if the bore is still in spec.Your piston skirts could just be worn or collapsed and just need replaced with a good hone job. Quote
jimbob Posted December 19, 2008 Author Report Posted December 19, 2008 You CAN'T go up to the next piston size without getting it bored.You could by the SAME SIZE piston if the bore is still in spec.Your piston skirts could just be worn or collapsed and just need replaced with a good hone job. ok thanks thats just what i needed to know. a definite no. lol ile pull the barrels and measure the pistons and bores, see which on is out of spec. cheers all ps whats a hone? a bore skim? Quote
firebanshee Posted December 19, 2008 Report Posted December 19, 2008 ok thanks thats just what i needed to know. a definite no. lol ile pull the barrels and measure the pistons and bores, see which on is out of spec. cheers all ps whats a hone? a bore skim? It's when you use a hone , i like ball hones, usually it's attached to a drill and you put a new cross hatch pattern in the cylinder to break in the new rings. Quote
jimbob Posted December 19, 2008 Author Report Posted December 19, 2008 It's when you use a hone , i like ball hones, usually it's attached to a drill and you put a new cross hatch pattern in the cylinder to break in the new rings. yeah i see what ya mean now. thanks fb Quote
firebanshee Posted December 19, 2008 Report Posted December 19, 2008 yeah i see what ya mean now. thanks fb :thumbsup: Quote
klemet banshee Posted December 19, 2008 Report Posted December 19, 2008 dont mean to hijack but i have a hone(its says glaze breaker) can i get away by honeing it putting a new set of rings? im starting on my 5th season of riding and its starting to lose some compression Quote
Bansh-eman Posted December 19, 2008 Report Posted December 19, 2008 as long as the cylinder is in round and you have to correct tolerances you can just hone it and be fine, but if you are out of tolerances or your bore is out of round you need to have it machined to get it back in specs. Make sure that any time you bore your cylinders that you have the pistons that are going to be used with the jugs so they can be matched. you can check 100 differant 65.00 pistons and they will all read differant so you cant just get your jugs punched to 65mm and call it good. or let me rephrase that, you "can" but you shouldnt Quote
jimbob Posted December 19, 2008 Author Report Posted December 19, 2008 ok i pulled the barrels and pistons but dont have the correct bore measuring equipment and its reaaly hard trying to measure a bore with a vernier. i measured the piston and that seemed to be in spec so with the process of illimination it must be the bore thats out of spec so they've gone of the the machine shop for a rebore and new pistons, better safe than sorry is what my old mum would say. lol thanks again to all for your help :thumbsup: Quote
Bansh-eman Posted December 19, 2008 Report Posted December 19, 2008 ok i pulled the barrels and pistons but dont have the correct bore measuring equipment and its reaaly hard trying to measure a bore with a vernier. i measured the piston and that seemed to be in spec so with the process of illimination it must be the bore thats out of spec so they've gone of the the machine shop for a rebore and new pistons, better safe than sorry is what my old mum would say. lol thanks again to all for your help :thumbsup: make sure you give the shop the pistons too so they can set the tolerances Quote
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