Blaster Blaster II Build , Jettting Question

[toddhales]

I currently have a Blaster II 760 that was rebuilt with new case, crank pistons and has a new rec mild port job from riva ,
I have the
big red riva pipe
Mikuni modified Buckshot carbs 44 - Spidgot type
Riva Girdled head 38cc domes
I had the same setup last year but I think I had a lean issue with engine, sometimes it would not go full htrottle and just bog.
Finally blew a rod and rebuilt engine .

Since engine build I am getting good compression almost 150 psi in both, IT dropped to almost 120 when it was hot ..
It starts up fine and idles ok but won't stay at idle , have to feather idle and seems ok up to 1/2 throttle
then it dies no power past half throttle. It's like riding with the choke on , but I don't have choke plates just primer.
seems like alot of white smoke when running and sucking the gas .
I tried pumping the primer while at WOT and nothing, no surge in power , so I think I am not lean


My plugs are brown alittle dark brown
WOuld I be running rich after a port job , should I lower my mains ?

or try reverse jetting with these carbs ? 120 L 120 H


setup is
120 P 135 H
Pop-off is 2.3 needle 80 gram spring , 15 or 17 psi

 

[CARBONX2]

I used to run 120P 130H with 46mm Buckshots on a 709cc WB1(ported). 120P/120H should get you close

 

[toddhales]

Thank , I'll try that , hope I don't have anyother problems

I used to run 120P 130H with 46mm Buckshots on a 709cc WB1(ported). 120P/120H should get you close

 

[DstnBlstr]

I had the exact same symptoms on my blaster. Turned out to be water in my fuel. Had a cheap paper fuel filter on it. According to my local mechanic the filter would swell from the water just enough to choke it and not allow enough fuel through. A quick swap out with a new filter and she runs like a champ again.