Guys this is really piising me off. I just swapped in an SE 13B in my GS and it sputters and backfires coming up to 6000rpm at WOT but before 6000 it pulls plenty strong? Heres the story. I pulled my carb(dellorto 48) from my old motor which reved to 8000rpm cleanly and put in on the SE motor. I was running a direct fire ignition but I switched it back to stock for now until I figure this problem out. At first I though maybe the timing was off. Timing is 0 leading @ idle and 20 trailing no vac advance. For fuel I'm using the Carter pump that I had on there before the swap along with the purolator regulator set at 5psi. Fuel filter is clean(see through) and I thought maybe my pump was going out so I hooked another pump inline to increase pressure and volume, no change so I figure its not the pump. I pulled the extra pump off that I rigged and put it back to normal(single pump). What the hell is going on? What should I check next? Coils maybe but both my tach works? I have one on leading and one trailing. Could it be the cold weather here in Buffalo? I never really drove this set up in the cold since it was on my summer car. I need HELP bad coz I'm running out of ideas.

Sorry for the long post!
Thanks, Ed
By the way is Gruntled.com down?

 

oops

 

maybe there is crap in the carb?

check your plugs wires cap rotor also.....

 

wires, cap and rotor is good. I'll change the plugs. What plugs should I use? BR8's or should I use the later 13B plugs 7 and 9's?

Thanks, Ed

 

are you sure you are getting enough fuel at higher rpms?

 

I think I was especially when I had two pumps running. It made no difference so this lead me to believe that fuel is good but I guess the only way to make sure is to hook up a gauge. What do you think.



Thanks, Ed

 

i would set the regulator low and see if anything changes. i would personally replace the worn pump with a new one and get rid of that second pump.

 

The carter pump is only 1 summer old and I only hooked up the 2nd pump to see if it would cure it. I have always had the reg. set at 5psi. Even on the old motor. I'll get a new pump anyways.

Thanks, Ed

 

Ok I had the same problem with my 12a bridgeport. Turns out getting different jetts solved the problem. Get your carb tunned.

 

hook up the 5th and 6th ports? jks.....lol

 

what size jets are you using?

 

I'm not messing with my jettings. This carb is tuned to a 12.8 quarter so I doubt its the problem along with my 6ports. I'm going to change the pump.


Thanks, Ed