Originally Posted by
deadmancourt
what size venturi would you guys run on break in on a gx5r for truggy? and what size once its ready for race tune?....i got 2quarts and 2tanks through it so far!...how many tanks till they are ready for race tune?
Run it in using the standard 8mm restrictor which is fitted stock. That way you can get plenty of fuel through it during break in.
Depending on your run-in method normally 15 tanks will see it free enough to start tweaking a reasonable race tune. You will know by how willing it is to wind out. If you lean it and it starts dropping off at the top end, then it's still too tight. Just play it by ear. It will let youl know when it's ready to really go.
Run the 7mm restrictor for racing to start with. This will give you a good trade off between power and economy, then see how you go from there.
If you want more run time drop to the 6.5mm. You will still get wicked bottom end with the smaller restrictor (sometimes more actually) and just a small reduction in top end, but increased run times once you lean the motor to suit the smaller restrictor.