[Bruce]

Hi,

I'm running a standard 1990 TRX 300 Big Red. I've currently got the carb in bits carrying out an overhaul. I was wondering if I could tweak the carb slightly by changing the jet sizes? Basically I want to squeeze as much power out the engine as possible without leading to damage. Will I see much increase with larger jets? Below is a list of the current jets fitted. Please advise if you recommend replacing any of the jets for more power?

Jet Sizes (current)

Main Jet = 120
Slow Jet = 42
Starter (choke) Jet = 85

Thanks,

Bruce

 

[Here 2 help]

You can get more power by installing smaller jets, but get too small and you will cause spark knock and burn a hole in the piston. If you want to burn more fuel, try running with the choke partly on. Otherwise - leave the jets stock! If you make other changes (exhaust, intake, cam, compression, ignition timing, carb venturi size), then you might need to increase the size of the jets.