help.. new to 4strokes

[Becareless06]

well here goes i traded for a 1993 300 ex
it has k&n filter with supertrapp muffler
it runs good on the low end but as soon as it hits mid to top end range it falls on its face spitin and spurtin i adjusted the valves and droped a few sizes on main jet and the plug is still so rich .. i found a big part of the sparkplug boot was gone so i ordered one and ordered new 14 tooth sprocket 1 is so low lol .. whats ur guys thoughts..im hopin its the plug boot.. thanks russ

[smr]

throw away the K&N, they let to much dirt by for off road. They are fine on a street bike or truck but I would never run one on my quad. I usually run a uni.

what size jet did you put in it? Even though the plug looked black you would have to use a new plug to get a good reading. Sounds to me like it was to lean.

[sm00th026]

Originally posted by Becareless06
well here goes i traded for a 1993 300 ex
it has k&n filter with supertrapp muffler
it runs good on the low end but as soon as it hits mid to top end range it falls on its face spitin and spurtin i adjusted the valves and droped a few sizes on main jet and the plug is still so rich .. i found a big part of the sparkplug boot was gone so i ordered one and ordered new 14 tooth sprocket 1 is so low lol .. whats ur guys thoughts..im hopin its the plug boot.. thanks russ
Does it have a air box lid on it??

[Becareless06]

no lid i put a new plug in when i put the jet in.. its 125 .. was 130and orginaly when i started jeting it was 160 .. ploit is 38

ill prolly go to the uni when i get it runing right.. i always liked my uni in my banshee"s

[sm00th026]

Originally posted by Becareless06
no lid i put a new plug in when i put the jet in.. its 125 .. was 130and orginaly when i started jeting it was 160 .. ploit is 38

ill prolly go to the uni when i get it runing right.. i always liked my uni in my banshee"s
try covering the box with a lid or something to cut down the air flow and see how it run's then.

[Becareless06]

ill try that my coil should be here in a couple of days..when it gets here ill let you guys knoe if it runs any better..

[smr]

your way to lean. With that supertrap I would start somewhere around 152. Leave the lid off.

[smr]

almost forgot, you may want to check the needle. It should be in the middle sometimes they slip through the clip and will cause this problem.

[Becareless06]

if i was way lean then why is the plug charcol black.. all thou i coverd the box up and it did seem to take fuel better

[Becareless06]

i have a heck of a rattle comin out of the motor too sounds like the timming chain.. but it goes away if u dont rev it..
how do i check the tenser ?

[sm00th026]

I would say leave the lid off if you still had the 160 main jet in it.But you now have a 125 main in it.And 120 is stock for the 300ex.so leave the lid on it, if it's running rich. Unless you go back to the 160 jet. Like SMR said have you checked the needle? And for the timming chain tensioner,My way to tell, is take it out, if it has a spring put it back together, .And push it on a wall if it slide's in any it's bad it should hold.

[Becareless06]

ok thanks alot for the help guys .. im gona check the needle and go get an assorment of jets 150 155 and 160..

i deffnatly dont want to blow it up from bein to lean.. im gona pull the tensioner out also.. and check that..

[Becareless06]

so i did some work to the 300 put my new coil on no change i put 158 main jet in and still runs like crap so ill try the 150 .. also checked the timming the cam was 3 teeth off so i fixed that.. im not sure wats goin on with it if u rev it it wont rev past 1/4 throttle pop and bangs spits black smoke out the pipe

[Becareless06]

well made alil progress today.. got the carb issue figured out.. it was pushing gas around the oring for the accel pump .. and put the lid back on with 125 main jet.. and put new oring chain..

[sm00th026]

Is it running good now? And if I was you I would take that Oring chain back, and get one without the Oring's.Just use a regular 520 chain.Because both have the same Tensile strength of 8200 pounds.And the Oring chain I know will kink up after time because the Oring's will block what oil you put on it from getting to the roller's of the chain. E-Bay has the regular chain from 20 to 25 Dollar's free shipping. That's the way I would go.

[redrider86]

KN are awesome filters! dont go with a "stock" UNI filter.
just make sure that you oil it properly and it wont let any dirt through :rolleyes:

[Becareless06]

well everyone has there prefrence on air filter ive never had any problem out of k&n
but people have . a lil up date on the 300
ive got all new bearings coming for it got a welder to weldup the swing arm bolt hole also picked up some 450r shocks
with 400ex arms still lookin for a cheap 400ex carb and new timing chain just for
added insurence . and looking for plastic
battery box start switch , rev box , im have tempted to tear the top end down to inspect for wear , and to have some one port my head