Running too rich

Post date: Jul 13, 2009 1:32:49 PM

I've got a strange carburetor mixture problem. The rear plug is dark and clear signs of too rich. The front plug is just about right. Frontline suggested I have a leak on the intake manifold and that I may need to drop one size in the slow speed jet. I pulled the carb and checked the manifold. It appears snug. Sprayed it with carb cleaner over at Dave's and we only heard indication of a leak at the carb mounting rubber seal ring. I dropped the slow jet from the stock .042 to a .040 and made sure I seated the carb tight. With the EV27 cam, ported heads, multiangle valve job, Ness Big Sucker I followed the Thunder Jet recommendation and bumped the Main jet from stock 170 to a 180 from their kit. This should not effect the richness as the majority of the time I'm running 1/4 throttle or less. However, at the end of day yesterday things seem worse. It now appears I have intake leaks on both sides of the manifold and the back plug is running even more rich than before. This doesn't add up. I needed to walk away for a day. I'll focus on getting that front wheel cut down to mount and revisit this carb problem later in the week.