Bike carb's or Holley for trackdays

mgbloke · Post by **mgbloke** » Tue Jul 07, 2009 4:47 pm

Well it certainly worked for me.
Wonder what was actually causing the problem?

wseight · Post by **wseight** » Tue Jul 07, 2009 8:05 pm

This sounds very interesting. Did you also suffer problems under braking before modifying the carb?

Regarding rechecking the float level to combat the problem of stopping, I have found two recomendations for float level, 11/32 and 7/16. What should I go for?

Cheers

Tor

mgbloke wrote:I had this exact same problem which is very frustrating and only happens on track when accelerating out of corners.
I was all ready to go down the injection route and then I found a Cure.

First of all remove the carb top and make another fuel inlet by drilling and tapping the opposite end. Tee the fuel pipe and have a double fuel entry to the carb.
Then Fit a High flow needle valve kit without filters.

This has transformed the car on track and I cant believe I suffered the problem for 7 years.

I dont think the double entry alone is enough but might be if you remove the small filters from the standard needle valves. High flow valves are cheap and available from the states.
This worked for me anyway.

I have tried the 600 carb on my 4.6, it made slightly less peak power but throttle response is MUCH better with the 500.

Im very pleased with my carburation and the only performance mods planned now are Merlin heads and maybe slightly larger dia exhaust.

Another mod worth considering is as I never needed to use the choke I removed the flap and spindle and also ground away the raised section that the flap sat on to ease flow into the carb.
Cheers
Mark

mgbloke · Post by **mgbloke** » Thu Jul 09, 2009 9:31 pm

I only had problems in corners.
The Edelbrock manual says to check float level if engine stalls under braking.
I used a 7/16 drill as a guage

Cheers
Mark

ppyvabw · Post by **ppyvabw** » Thu Jul 09, 2009 10:58 pm

Soz bit drunk again, may not be remembering the subject of the thread correctly.

Could be too high fuel pressure maybe? The bouyancy of the floats is the only thing keeping the valve thingy closed, Maybe the pressure is so high that it overcomes the bouyancy of the floats when the fuel is sloshing around on bends and braking etc...They like about 4psi don't they?