Need to richen mixture of vegas tuned carb.

[KRAZYMATT]

I finally got my fuel issue figured out and all seems well. Have been able to run it up and hold it open for a while it but shudders and surges at WOT unless I have the choke pulled about 1/4 the way. I'm guessing it needs more fuel. I have predator 420cc with open air filter, free flow exhaust with car muffler and offset timing key. Motor has vegas carts tuned carb... can the jets be changed on this carb or is there adjustment I can make to mixture screws somewhere? Seems to be fine in all other areas. Idle is fine, maybe a tad high, will idle all day long.

[KRAZYMATT]

Caved and ordered mikuni vm34 flat slide carb.

[raydhd]

That's a whole lotta carb for a clone.

[fstg21]

Also, check for any vacuum leaks with a can of carb cleaner. if it's lean, it's often a gasket issue.

You can buy jets as well

[rayjayy]

Jet drills.

[KRAZYMATT]

Opened up the main jet with torch tip cleaners. Seems good but still can't get idle right or smooth all way through power band. Also still having trouble keeping fuel to the carb.

[fstg21]

Originally Posted by KRAZYMATT

Opened up the main jet with torch tip cleaners. Seems good but still can't get idle right or smooth all way through power band. Also still having trouble keeping fuel to the carb.

What are you using for a pump?

Vacuum signal from?

If it won't idle you might have a vacuum leak.

[sho305]

Clone carb? Usually have to go way rich on main to get the power WOT then it gets too rich at 1/8 throttle where the main starts to work. Idle you have to remove the plug to get at the mix screw next to the intake spacer, some they break the screw off you have to heat it (I used a solder gun) to release the loctite and put a groove in it so you can screw it out then buy a new one. You can get them to idle nice and slow once you get the idle mix right, you may have to pull the idle jet in top of carb in that plug and enlarge it a little to get enough fuel to the idle mix screw.

I could never get it to run right at low throttle so I finally bought a 32mm CV pumper scooter carb and it is working well with a big long intake so the carb is over the cylinder. It may not have full power yet I have to do some final jetting but it runs nice very smooth at any throttle and idles nice and slow.

[KRAZYMATT]

It starts up pretty good just by feathering the choke. Once it's running it idles fine just a little high- Clutch stays engaged and is hard to shift. I was hitting the choke a little to make the engine stumble/drop rpms shift it and let back off the choke to shift it easy. Seems good at WOT now doesn't bog. Cart hit 27mph where before I could never get more than 23 from it but I also redid the whole exhaust, added the roller rockers, and advanced the timing 4 more degrees since last time I ran it... it would probably get 28 but I let off it since my tires so outta whack it was bouncing kind of crazy. Still having fuel delivery problem. 2-3 times the carb ran out of fuel. Each time I'd lift the seat blown in the tank vent the lines would fill up, start back up and it was good for awhile. Put around 4 hours on it this weekend. Was nice knowing I wouldn't be stranded but wish I could figure that issue out!

[KRAZYMATT]

Originally Posted by fstg21

What are you using for a pump?

Vacuum signal from?

If it won't idle you might have a vacuum leak.

I'm using round black plastic mikuni pump they use on the 15-30 hp motors. -it's the same as the honda one you posted on my other thread. Pulse signal from the carb spacer on the intake. It idles just idles high and makes shifting hard.