Hey all,

I need some help with my engine, it's just a basic sport engine which came with my Ultima RB.



Anyway, i disassembled the carb to clean it out, and noticed that the barrel in the carb has a 4mm throat (!!). The inlet of the carb is 6mm....but the throat is tiny!!

I see this as a big restriction, and i plan to bore it out to 5-5.5mm......can anybody give me any tips or suggestions as to how i should go about this, and any problems i may get from doing it?? I'm also going to remove 1 head shim to try and raise compression, will i need a different glow plug if i do this??

I have added a tuned pipe, and matched andpolished the exhaust manifold. I also added a higher flow filter than the stock one, and oil and clean it regularly.

I am starting an offroad buggy club (we have an unused BMX track to race on) and i will be racing mainly agains other RTR's such as Evaders (.18 O.S.), and want to better my chances of keeping up.

Thanks in advance,

Jamie