Need help with 421 cub jetting

[chabknot69]

I've got a 421 cub with 39 pwk's w/ power jets on Meth. Currently I'm running 155 mains, 55 pilots, and an EGQ needle. I'm just wondering how much of a jetting change I need to make for a weather change from November to now. I'm located in San Diego and do pretty much all of my riding at Glamis/ Buttercup. Also I'm interested in possibly making a trip up to Pismo for Memorial Day or Fourth of July. It's obviously too hot in Glamis at that time. Any help would be much appreciated.

[fastbanshee8]

As a general rule, they say that you should increase the main jet size 1 size, for every 10-15 degrees the temperature drops, and drop the main jet size, 1 size, for every 10-15 degrees the temperature increases. This is a pretty close to being right on, provided that you are jetted correctly, or very close.

[badassbanshee479]

I hope your main and dump tube have been drilled, if you are infact only running a 155 main you will burn that engine down on alky!

 

get the jetting close ith the main jet, then use the power jet to adjust for temp changes

[chabknot69]

Ok thanks, yes they are drilled. How about the needle, and pilot? And does they elevation from 300 to 50 feet really matter in the change? It really sucks that my tuning has to be done 2.5 hour drive away. As I've mentioned I live in San Diego and if my bike's running for more than 30 seconds I get complaints. Very very gay. Thanks for the help. Is the drive up to Pismo worth it?