cylinder help.

[thejake456]

ok, i need my cylinder honed out and am gonna do it but was wondering if all you have to do is measure the bore size with a caliper and get the right piston for the size of it??

my one friend told me otherwise but i dont think he really knows what he is talking about!

 

[_JOE_]

Check to see what pistons are available first. I assume it's not plated right? You generally hone to achieve proper clearance.

 

[thejake456]

well right now the bore is 47.80 so i am assuming it is boared 80 over now. and on denniskirk.com they sell a whole piston kit that the bore is 48mm for my bike???

if i do that it would be boared 100 over right???? what cc's would that make it??

 

[2strokerfun]

What bike?? I assume this is like a 72cc bike, if it has a 47mm stock bore.

 

[thejake456]

99 cr80r

 

[thejake456]

can this bike be honed out???? i have heard that some cant be cause of what the cylinder is made of?

 

[tyler_43]

you can't "hone" a cylinder in order to fit a bigger piston in. Honing only takes small amounts of metal off, just to acheive proper clearances. To put a larger piston in you need to BORE the bike out... but seeing how your bike has a nikasil plated cylinder you would have to replate the bore after doing so... which costs $$. Your bike came stock with a 47mm bore and a 47.8mm stroke (82.8cc). I think this is where you get the 47.8 from, as most piston manufactures make pistons in .5mm incriments. What you need to do is get somebody that knows what they are doing to measure the bore and tell you the size... once you find out that information order the correct piston for it. You can find pistons from 47mm to 52mm on www.wiseco.com

 

[thejake456]

could it be honed out .2 more????

 

[_JOE_]

No, honing is only used to hold lubrication in a plated cylinder. Why do you want to hone it?

 

[2strokerfun]

No, honing is only used to hold lubrication in a plated cylinder. Why do you want to hone it?

Don't forget non-plated cylinders. They are honed also.

TheJake: take your cylinder to a shop and have them measure. If you are correct, you'll have to get it replated or bored and replated to bring it within specs for new or oversized piston.

 

[_JOE_]

Let me rephrase.......In a plated cylinder, honing is used to hold lubrication.

 

[thejake456]

it now sputters at high rpms and it still cuts out at 1/4 throttle to idle like before. i think it isnt jetted right. could that do it?????

 

[thejake456]

could that be the float?