jetting problem i think?

[Cartkid14]

ok i just got my shee running and it starts right up and seems to run great. but when i put a load on it, it just wants to surge or pop. but when i free rev it, it winds right up, also when im in like 4th or 5th gear and i try to give it gas it smokes alot. also i just had the crank seals replaced. so i want to say the main jet it to big. but i know nothing about jetting and i dont know what jets are in it right now. so some info would be awsome. im going to silver lake sand dunes in 2 weeks and i need her running good. also the shee is mostly stock. only has a boost bottle and a k&n on it i beleive. also i just put new boyson reeds on today. but its done the surging sense i got the atv. oh and it only does the surging between 1/2 and full throttle......

[CarvedArt]

The carb is made-up of 4 main circuits that overlap each other:

0 - 1/4 = Air screw & Pilot Jet (The brass screw on the left-side of the carb, in = rich/out = lean; & little brass "screw" on bottom of carb, inside fuel bowl, next to the main jet)

1/8 - 1/2 = Throttle Valve (The angle cut on the leading edge of the carb slide)

1/4 - 3/4 = Jet Needle (The needle in the center of the carb slide, clip up = lean/clip down = rich)

1/2 - Full = Main Jet (Brass hex on bottom of carb, inside fuel bowl, next to the pilot jet)

 

So if your having issues from 1/2 to full then you're looking at the Jet Needle and the Main Jet as well as your Float setting.

"Smokes alot" could be related to your premix-ratio and/or your jetting being too rich or a coolant leak (depends on the color/smell: whitish/sweet=coolant; blueish/greyish=oil, sweet=premix, foul=case).

 

You must make sure your floats are set correctly (21mm from the gasket surface, (not the gasket), touching but not compressing the needle valve bumper)

 

When an air-fuel mixture is too rich:

The engine noise is dull and intermittent

Condition worsens when the choke is opened

Condition worsens when the engine gets hot

Removal of the air cleaner improves the condition

Exhaust gases are heavy/oily

Plugs foul

 

When an air-fuel mixture is too lean:

Engine overheats

Condition improves when the choke is opened

Acceleration is poor

Engine RPMs fluctuate and lack of power is noticeable

Plugs burn

 

You should also sync your carbs.

 

Rough Calcs...

Stock Mains = 210 (plus/minus 10)

Boost Bottle = No change (Make sure the rubber intake isn't cracked around the bottle holes)

K&N w/ airbox = 4-6 Larger Mains & 0-1 Larger Pilots

Boyesen Reeds = 0-2 Larger Mains