Carb Help

[dave_noffsinger]

My best friend and I picked up a Raptor 80 for his son. It's used and will be a x-mas gift for him.

Anyway, the bike seems like it's running rich and is flooding out. It's hard to start and when I pulled the plug I smelled gas pretty bad.

The bike has a FMF power core pipe and the guy we got it from said he jetted it. We both were thinking maybe the jet is to rich but I'm not sure. I pulled it out and it's got a 76.3 in it. I'm not sure what the stock jet is so I don't have anything to compare to. I'm not much of a carb guy either so any help here would be appreciated.

Thanks,
Dave

[bwamos]

This should help some.

Duncan Racing Jetting Guide (http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml)

[Colby@C&DRacing]

Most of the mini quads do not need rejetted with a pipe stock jetting to rich as it is.

[raptorred660rf]

you mite need a different size needle for your carb

[dave_noffsinger]

Originally posted by bwamos
This should help some.

Duncan Racing Jetting Guide (http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml)

Thanks for the link. That helps.

I took the carb off again this evning and cleaned it out again. I had a guy at a local shop mention adjusting the needle on it but I havn't actually gotten that far on it just yet.

I do still think it's rich though. I had the air intake hose off of it when I put the carb back on and I saw a lot of gas spitting out of it. Seems like it starts better if If I make sure the gas petcock is off after running it. Then start it while it's still off and just turn it back on after it gets going.

I'm going to do some more poking around and reading. Like I said, I'm not a carb man. So far I'm only mildly pissed with it. I'm sure as I go this will bet worse. Hopefully I'll get it figured out and dialed in before I take a 40 oz hammer to it, lol.

Thanks for the info guys, every little bit helps!

Dave

[dave_noffsinger]

ok, I pulled the carb, several times now, and cleaned the crap out of it. It's got a 76.3 main and 12.5 pilot. These are the stock jets, I checked up on that. I've gone through the whole process of setting the air screw and have tried out all 3 needle positions. Though it seems like it's getting better it's still having a hard time on a cold start. Once it's warmed up it's fine to shut down and restart. Just the cold start that is the problem here.

Right now I have the needle set on the 3rd notch down, which is the richest. Seemed to help. The air screw is 1 turn out. When I was messing around with it I had the air intake hose off and noticed that a lot of gas was spurting out the front of the carb. It keeps acting like it's flooding out after it sits for a while. I've tried cutting the petcock off when I shut it down and it does seem to make some diffrence but it's still really hard to get cranked from cold.

I also checked out the compression which is running good. I dropped a new plug in it as well.

So, any ideas on where to goto next? I'm getting stumped here. This is starting to get under my skin here. I can't help to think that it's just flooding it'self once it sits around for a while. Could this be a problem with the float? If so, how do I adjust/fix that?

Ok, off the soap box. Any help would be greatly appreciated. Also, if anyone wants to come over to the garage and lend a hand getting this thing running right I'll be glad to buy some beer and a pizza!

Later,
Dave

[dave_noffsinger]

Update:

Ok, I have gone through and checked the valves and top end. It's all in good shape. I'm still having issues getting this thing to crank up from a cold start. I had the air intake hose off for a while in the garage. It's spitting a good bit of gas out of the intake. If you put your hand up there and rev it several times you'll end up with wet fingers from the gas. Any ideas of what would be causing that? I also checked the choke out...seems to be working as far as I can tell. The plate opens and shuts fully with the choke lever.

I never had a carb spit out gas like that. Any idea of why it's doing that?

Thanks,
Dave