Actin Funny

[Halter]

Well, it acts funny once in awhile..like when I am full throttle in all low gears shes all there ..but once I am in 5th wide open she acts like she pops and sputters once inawhile....well anyways I was riding it around just crusin around the yard going to my bros which is across the road u know just like 3rd gear little above idlein around..well I parked it no prob..well she wouldn't start...for some odd reason next day...well she backfired and I know..gotta go get a plug..but .. can anyone tell me wh y shes acting funny on me....I put a R4 slip on it .. and a 160 size jet...
soo I dont know....shes all there low gears though dang

[EXevan91]

you clean your air filter lately. is the filter dirty ?

[LT250RMan]

try taking the carbarator apart and cleaning it maybe.

[Choppers]

if it fouled a spark plug you might be to lean or righ

[Halter]

ok..clean airfilter.....and maybe should run it with out air box lid once see if it doesn't sputter on top end?

[GPracer2500]

Originally posted by Halter
ok..clean airfilter.....and maybe should run it with out air box lid once see if it doesn't sputter on top end?

Yes. This is a good technique for evaluating jetting. If the condition improves without the lid on then you're too rich. If it gets worse, you're too lean.

You can also use the choke (most choke types, anyway) to perform a similar test. Engage the choke a little--maybe 1/8 or 1/4 from full on. If the condition improves you are too jetted too lean. If it get's worse you are too rich.

Often a slightly rich or lean main jet won't materialize as rough running unless you're in a higher gear. In lower gears there isn't enough load on the engine and the RPMs build so rapidly that bogs/misses/studdering/etc. are masked. The engine's momentum and rapidly building RPMs can clear out rough running before they are noticed.

It's not that a main jet being rich or lean as anything directly to do with RPM or what gear you're in (it doesn't: within the context of this discussion, the function of the main jet is related to throttle position only). It's that in some RPM and gear combinations an engine can overcome and cover up the signals that reveal if you're rich/lean.

[Halter]

Originally posted by GPracer2500
Often a slightly rich or lean main jet won't materialize as rough running unless you're in a higher gear. In lower gears there isn't enough load on the engine
exactly what I am saying...on top gears she sputters at full throttle and low gears shes got all her nuts there

[krt400ex]

Originally posted by Choppers
if it fouled a spark plug you might be to lean or righ


if it fouled a plug, then it's rich. a dirty air filter could cause it to run rich because it would restict air flow

[ilpadrino113]

ya it sounds to me like yer runnin too rich. Try cleanin the air filter and then take the airbox lid off if it isn't already. If it runs better off, then yer too rich.

[tar]

I am running a 160 main with a full system K&N w/ no lidand my is good so it sounds like your rich.

[Halter]

yeah I am going to try it with no lid..I put the new spark in today and she fired up..... i took her out for a test run..and shes runs awesome on full throttle 5th..but its like 3/4s throttle she starts to sputter a bit