Hello I have a 2003 660r raptor, with a edelbrock carb.. I have checked everything cleaned carb, filters cleaned new spark plug, good coil.. Adjusted carb in all settings.. have no idea whats wrong.. any help.. The problem is in higher rpms it hesitates.. seems like loss of fuel but it still runs good.. if you have any questions just feel free to e-mail or reply to thread.. Any help would be great...

 

warm up the machine, run it to high RPMs in every gear, and then stop it, and immediately pull the plug. If it's a carbon black, you're running rich with too much fuel. If it's white, you're running too lean with not enough fuel. You want an ideal marshmellow brownish, if the plug has the right color it's probably not the carb. Tinker with the settings to correct the condition of the carburetor if it turns out black or white.

 

Thanks i changed the spark plug and the plug that was in it was the marshmallow color. What curve on the ignition switch should i be using? it has Stock curve 1 curve 2 curve 3.. Not sure if that has anything to do with it.. i usually just adjust so there is no smoke out tail pipes and little gas smell on ignition.. Dual exaust, k&n filter, aftermarket ignition.. in case you were wondering.. Thanks Again for the help

 

Ok here is what i came up with.. does this sound right? The bike runs good but in higher rpms it cuts out.. all gears like 5 grand or lower.. Could it be the aftermarket ignition giving bad firing signals? The carb is good the plug is good.. Dyna FS aftermarket ignition.. That is what i heard it could be.. Does this sound right or should i dig deeper?

 

Forgot to mention hard starts on first second try.. Have to hold in starter to get it to fire....

 

If it just cuts out completely and it's not hitting the rev limiter it sounds like it's sucking all the fuel out of the carb. Check and make sure it' getting good fuel flow. Check lines and petcock for blockages. My yfz does the same thing.

 

I will try that.. Tomorrow and post back.. Thanks that would be great... it would save me from buying a new ignition box...

 

As i said I have the same prob. I did change out the box. It didn't make a bit of difference but, we're not 100% sure thats your prob so don't rule it out just yet. Mine cuts out at much higher rpm's. prob 8500 to 9 grand. It's at the range it don't bother me much anymore. I don't hit that range often. At 5000, that would probably bother you quite often.

 

OK here is the weird part I cleaned the ballcock and fuel line and tank.. The 4wheeler cuts out in regular fuel but with it on reserve it runs a lot better on reserve.. Could the edelbrock carb be sucking that much fuel.. Oh when i was running down the road the rear sprocket bolts came off and I had to find a way to my truck to pick up the quad.. Wow what luck...