Any Ideas?

[thunder938]

 Hello,   In the turns as I start to get on the gas the tone on the  motor  is diff. as I am starting on the gas.  Once floored the car "clears"  out  sounds great and hauls the mail.  This get worse as the nite goes on. By the the start of the main the car even runs bad while sitting in the pits and wont "clear out", but once on the track at high rpms it does  clear and sounds fine at high rpms. This is wrose at the high speed tracks we go to. ONe track that has slower turns it still may do it but not as bad. This happened last year and I talked to REDLINE and he said to tune in the
air valves on the top of the carbs a 1/4 turn.  This did not solve the problem.  Well that motor broke the crank (1250 with 8 races ).  SO new year fresh built motor and carbs from the same builder.  NOT the same set of carbs as last year. I have a red box on the car, but ppl are tell me that the box will die not just in the mid range.
 This happened last night the car would not run well even in the pits. So today pulled the plugs..not bad.  I was expecting then to be black. change the fuel filter and adjusted the choke cable and the car
started right up and sounds sharpe as a tac. I put a lazer temp gauge on the header and running on all 4 temps very close to each other,

 So......any ideas? A motor builder advised Carbs, Carb guys said not the carbs, I have heard fuel filter?  Tech guys said carbs not the box?  So............??
 
 

[elimn8u_43]

I would suspect any common parts that have been used with both engines. I would look at he fuel and ignition system. Hope this helps.

Geoff

[Legendracer24]

have you low-end jets tuned. Happened to me too. Also check the equality of the butterflies. ALL OF THIS= get your carbs tuned ASAP.

[justfreaky]

I am suspect of  jetting.
Equal opening of the butterflies; 
As it is multiple carbs; being out of sync could create a problem.
Should be easy enough to check.

Keep us up to date on whatever changes you make, and the results.

Steve

[RickyBobby]

I agree with the jetting.  There is an air jet (cannot remember the name right now) that controls low end throttle response.  You can get to them as soon as you pull the air filters off.  I took my car to Atlanta jetted for Canada and had the same problem.  Got back to Canada and the problem was gone. 

[thunder938]

Thanks, I have a guy that has a set of set up Hank Scott carbs that he will let me try.  If the problem is gone then I will send mine out, if the problem is still there then I guess a red box..

Dave