Briggs Raptor tuning

[Kinkra47]

I finally got my raptor running, but need some help to work out the bugs. I purchased the engine used, and it's been sitting for at least a year.

It starts easily and idles well after a brief warm up, but when the throttle is applied, the bike barley crawls and this is with no one on it. It just seems to have no power. it will stall out if revved to quickly and tends to back fire. Turning the fuel screw helps, and I think I've found the best setting for it, but something else seems to be the culprit.

I have a fresh and correctly gapped spark plug, fresh gas, the carb has been thoroughly cleaned and rebuilt. The linkage fully opens the throttle, but it just doesn't rev high, or seem to make full power.

Does this sound like a valve adjustment or timing issue, or both?

Any ideas are appreciated.

 

[5horsebriggs]

Sound like it is running way to rich or way to lean if it cnt rev up

 

[roccosbike]

check the jet and better yet under it for signs of the carb being modified for alky.

 

[Kinkra47]

Thanks guys. It looks to be running very rich. The pipe is very sooty and the plug is black, both of which were new and never run before today. The jet looks to be drilled. I compared it the the jet in the stock pulsa jet carb that also came with it. The one in the raptor looks to be 3-4 time larger in diameter. Fortunately the metering bikes behind the jet, seem to be unmolested. I will ultimately purchase a new jet, but has anyone tried soldering up an over sized jet and re drilling? I'm gonna give it a try.

 

[5horsebriggs]

Thanks guys. It looks to be running very rich. The pipe is very sooty and the plug is black, both of which were new and never run before today. The jet looks to be drilled. I compared it the the jet in the stock pulsa jet carb that also came with it. The one in the raptor looks to be 3-4 time larger in diameter. Fortunately the metering bikes behind the jet, seem to be unmolested. I will ultimately purchase a new jet, but has anyone tried soldering up an over sized jet and re drilling? I'm gonna give it a try.

I have heard of soldering and re drilling somewere, but what the heck give it a shot

 

[davidlamb78]

Probably set up for alky. If so, you might look for a different carb. Mine was set up for alky. I think most guys that ran raptors did so on alky. I'm in the same boat. I have a thread somewhere here wher someone recommended a Tecumseh carb with a 1" bore. I found one for $30 plus shipping on eBay. That would allow you to mount your tank someplace else.