I know any Raptor with High Comp. Piston,Cam,686,Exhaust any of that crap. The stock carbs will run out of gas at the end of a long run. Every one I talk to including myself has had to raise the float level to compensate for this. I found that this makes the needle and pilot jet area of the carb almost impossible to tune right. Has anyone thought of a small maybe 1 lb fuel pump? Would the stator be able to keep up? Would this fix the problem with running the carbs out of gas? I want your Opinion on the Idea. I really want to keep the stock carbs not that I'm partial to them just don't want to spend the major $$. Maybe I just need some carb tuning tips.[img]i/expressions/face-icon-small-wink.gif[/img]

 

How could you run a fuel pump with a float and neddle set up? Anyways I've got mines running like a screaming eagle jetted 200/205 so you know it's drinking some serious fuel and after some modifications to the stock carb mines hasn't run the bowl dry yet.

 

Thats the same mains mine was running when the float level was in the recomended setting. I couldn't get it to run out of fuel any where else except the long WFO pull at Sand Mountain Nv. If I would lug it a little in 4th gear it would go to the top without running out, but run it in third just screaming and it would run out about 3/4 the way up. I raised the float level and went to 175,180 mains and it runns good and doesn't run out of gas but the Idle and Mid range are rich.

 

I did a leak down test to see how much gas flowed in to the carbs in a minute and i got a whole cup to fill up(Im figuring that should be enough Gas that flows through there),so our conclusion is that they are floating enough gas,but i also heard that after 175 the jets dont flow anymore...I know that some builders friends of mine are working on the mods you guys are talking about,so give it some time and they can modify your carbs to run the right flow..when you say running out of gas what does it feel like,i havent run nothing that long like sand mountian,so does it just stop or does it burp after a long hard run,mine has done that but i was thinking about the carbs were just floating from being wide open..

 

Hiram, I'm not sure how the pump would work with these carbs. The Float would still shut off the fuel from intering the float bowl Just like a normal carb on a car would.(as long as the needle valve and set were stong enough) I'm working on making the stock carbs take fuel from both sides Not just the left. And using a petcock that has two feed lines.

 

Raptor03, It feels like you just took off on your bike and forgot to turn the fuel petcock on.

 

Pm me with the info on how it works..Thanks

 

No this is after 5 wide open runs,it stumbels at the end of the strip but doesent shut off or anything..

 

Lowbowtie, I like the dual fuel inlet idea, Ithink your really on to something there.

 

I think that This might help for flow. If you look at the right carb on the out side you can see where the fuel flow is coming from the other side. The casting is just not drilled out, I think if I drill that out to accept a fuel fitting and allow the carbs to accept fuel from both sides this might cure the prob. I also seen Alba sells a petcock that has two outlets (for guys running NOS) This would allow for true dual feed. Like I said I'm not sure if this will work but I'm just tring to help out everyone (and myself) that may have this problem that wants to stay with the stock carbs.[img]i/expressions/face-icon-small-smile.gif[/img]