backfiring jets maybe?

[nightmare420]

alright the electric is ok for now(still a problem somewhere but lets move on) i changed the stock main jet from 145 to 155,(k&n, no lid, fmf powermax)the bogging issue i had was somewhat cleared up but still have a backfiring issue. happens when i let of the gas to shift into basically 1st to 4th. when it gets into higher rpms it seems to not pop as much. also happens as im stoping and shifting down. after i put the jet in, i changed the plug and rode one mile. the porcelin tip on the plug was clean as hell. pure white. not sure if i need to go to the next higher jet or what?! trial and error kills me:argh:

 

[nightmare420]

could it be the mixture screw? what is stick? i will try and work my way up from there

 

[JonS]

you shouldn't need more than a 155 for that setup. what's your pilot jet size?

 

[duneracerweston]

White means lean so id jet up some

 

[nightmare420]

lol u guys both gave me dif answers. i dont know what the pilot is. most likly stock, since everything else is. just a guess tho

 

[duneracerweston]

Have you checked the intake boot for cracks? Or tears?

 

[nightmare420]

yes i have. there is no tears in the boot...

 

[duneracerweston]

hmm rev limiter maybe? have disabled those?

 

[nightmare420]

i took the parking break and clutch sensor off. not the rev limiter.. dont see how it would help tho?

 

[duneracerweston]

Have you adjusted the nedle yet? And what type if gas are you running?

 

[nightmare420]

i have not adjusted the needle. i honestly dont even know how to get that far into the carb, like i said its my first 4stroke. =( and again i have a new problem. i took it for a ride to test out if the adjustments i made on the mixture screw help, and got into my trails n did a few laps, then she died. some weird sounds were coming out of it. motor wouldn't turn seemed like but the starter would. then i got it running n booked it back to my house. now i have a very odd flapping sound coming from the red cover on my head. and i can also hear like a light screeching sound every once in a while? idk guys. but i have the worst luck with this stuff i will say that lol

 

[nightmare420]

btw its coming from the left side of the head.(not exhaust side)

 

[duneracerweston]

Hmm have you checked your timing chain?

 

[nightmare420]

nope, not sure where it is. im about to search the forum and check

 

[bones]

its the big side cover on the head

 

[nightmare420]

its the big side cover on the head

thats where it sounds like its coming from

 

[nightmare420]

my manual says timing chain adjustment; adjustment free. ? lol thats all it says about it

 

[duneracerweston]

The tesioner is spring loaded and self adjusting that know on the left side of the cylender is the timing chain tesioner take the 2 alen or 8mm hex headed bolts out and alow the tesioner to fully extend then re insurt it and measure the gap between the matting surfaces anything les then .1/8th inch is about time to chainge the timing chain

If good loosen the 12mm bolt in the end of the tensioner remove it and the spring inside now push the locking meckanisim and push the tesioners rod back into the tensioner reinsert the tensioner first tighten the 2 alen or hex bolts then reinsert the spring and 12mm bolt and make sure they are tight and your good to go

 

[nightmare420]

Im gonna have to take a look inside there and see. Im not gonna know what anything is inside there but i will try

 

[nightmare420]

just got the fenders off. gonna try n find the chain in a bit here