I was messing with my full fuel screw the other day on the 91.5 in my sig. After 1 1/2 turns, it felt like it bottomed out. The lock-nut was still loose and I could not turn the screw even with a ?/64" box wrench on it.

It made only a slight difference in performance.

BTW-I have the star wheel turned all the way down, the fuel pin turned for maw travel, and the stock 21cm housing. I get a puff black smoke at a hard launch from stand-still, then it clears up. I get occasional 900* post turbo egts.

Did I read somewhere about "short" full fuel screws? If so, do I replace it? Do I weld in it? If so how much? Or, is it something else?

Thanks.

 

Didja clean up the threads?

Guys have welded extra material on the end and smoothed it over. I think I'd buy a new one before I did that - just in case I screwed something up.

The hex is 6 mm.

 

the collor on his truck was not welded just crimped and bottoms out befor it even gets to where the messed up threads would be,

it didn't make sense to me when i was looking at his truck, only goes 1-2 turns in from stock maybe not even that far

 

I did not have the tiny metric, but one of my little, old time, ignition wrenches seemed to fit perfectly

Yeah, looking at the pics on another recent post I can't see how it would bottom.

 

The unthreaded section around the O-ring bottoms in the pump casting.

 

Mine bottomed out but after a lot more turns than that. I took out the TIG machine and added a little metal to the end. Just be careful with the heat and you should be fine. If you have a TIG machine you shouldn't even have to smooth it over.

 

mine did the same.. about a turn and a half and thats it. i was expecting more