re-jetting the carb

[Frankie39]

just a quick question... with the YX160cc motor and the big bore exhaust will the carby need to be re-jetted for the new exhaust?

 

[sean01]

shouldnt but could...lol

you wont know till you fit it and do some plug chops..

 

[Frankie39]

straight down the middle that one lol

 

[thump*140]

given that pipes on pitbike engines do **** all in the way of increasing performance, i doubt you'll need to rejet... they arent as sensitive to exhaust changes as a two stroke engine...
you may need to go up a point or two on the mainjet to cope with the extra air running through the engine, but i doubt it...

 

[Frankie39]

i must admit though, the stock exhaust on the bike is pretty beefy. sounds pretty good. but just got it cheap off a bloke at work, so why not put it on...

everyone has said stay away from the atomik bikes but i love my nitrous... i have lock tighted alot of stuff so maybe that helps, but all in all for what you pay its doing its job pretty well

 

[sean01]

yeah the nitrous seems to be a pretty solid bike, shame the rest of their mini's arnt the same..

 

[Frankie39]

on the topic of munching plugs, i just checked mine, havent touched the bike at all... only set it up 4 days ago and been riding it a few times, the plug is BLACK!, so either the plug is stuffed from it being just running in, or the carby is not properly set up... havent touched the carby either.

 

[sean01]

ok, could be black from a couple of things..

bad carb tune or mixture setting
sht china plug with poor spark output..

 

[Frankie39]

it was a denso plug. denso are an ok plug. im not too sure when it comes to carby tuning these things... not even sure how big the carby is...

so there is 2 main screws on the carby.... the massive one with the spring on it and the little one next to it that needs a flathead screwdriver to turn it... what is the best adjustment when its running very rich?