what should i be asking for in terms of overboring at shop

stankyoleman · Post by **stankyoleman** » Mon May 01, 2006 12:19 am

my local honda cycle dealorship/service center says they can bore out my cylinder just fine, and order a matching piston.... the only question i have, is what should i be asking for in technical terms... i'm looking to get the most out of it... any ideas?

*i know i could get a dio engine guys.. i'm trying to stick with what i have*

hrnytrtlsgsxr · Post by **hrnytrtlsgsxr** » Mon May 01, 2006 1:39 am

i dunno but i know for like yamaha yz80 motors they have NOS once over.pistons up to 4 times over pistons. I am thinking a once over is like .25mm over the stock piston.check it out cause i believe that is what the guys at the shop are referring to . Or atleast that is what I hope for.I figured that weisco probably made a once over but not till recently I knew they oem once overs were made.Well hope this helps.

darat · Post by **darat** » Mon May 01, 2006 11:40 am

that would be nice but i dont think that it will do anything for it.

Post by **noiseguy** » Mon May 01, 2006 4:57 pm

.5mm over is as big as Honda sells. Maddog had a line on some JCC pistons that are 2mm over (for 43mm total.) I have a couple on the shelf here that I need to fit up.

stankyoleman · Post by **stankyoleman** » Mon May 01, 2006 5:07 pm

does maddog still have that connection? i'd be interested in grabbing a piston and some rings 2mm over

Post by **noiseguy** » Tue May 02, 2006 8:59 am

PM him or email him regarding it.

mopedman · Post by **mopedman** » Tue May 02, 2006 10:05 am

stankyoleman · Post by **stankyoleman** » Tue May 02, 2006 4:17 pm

after having the cylinder overbored, i'd need to upjet on the carb right? if so, how much. i have a 68 main on my carb right now for the sb engine, but i'm going to try out some k&n filters and go and buy some 75-90 main jet to experiment...

darat · Post by **darat** » Wed May 03, 2006 1:55 pm

have fun.. it is a big * pain to keep one changing the jets..

stankyoleman · Post by **stankyoleman** » Wed May 03, 2006 4:05 pm

well i have a lot of free time on my hands in the spring

darat · Post by **darat** » Thu May 04, 2006 12:06 am

yeah i can tell..

MySpree · Post by **MySpree** » Thu May 04, 2006 8:10 am

yea, its a bit carb jetting cuz carb on carb off carb on carb off,,

stankyoleman · Post by **stankyoleman** » Thu May 04, 2006 11:28 pm

so with the 43mm bore cylinder, what would anyone suggest for main jet# changed to

Post by **noiseguy** » Fri May 05, 2006 2:24 pm

I'd start at about 70 - 75 for stock filter box. It'll bog out and run a lean plug if the jet size needs increased.

stankyoleman · Post by **stankyoleman** » Fri May 05, 2006 11:35 pm

yeah maddog pmed me about the pistons, says he still can get them, i just have to call my shop and ask about if they have a 42 mm bore, which im pretty sure they do.