I was riding the other day, It was very hot out. Everything seemed fine, I took off from a light and the bike started running rough so I pulled over. after messing around with it, it was not running on the front cylinder. I limped it home. I check the coils for ohm tests and were fine, both plugs have good spark. Both plugs looked clean, tried different wires with no change.
A compression test had about 25 to 40 psi. I put about 40psi of compressed air in the plug hole, and it seemed to be holding, except where the reburn holes are where the carb bracket connects to the top of the cylinders. A faint stream of air came out there on both cylinders. no air loss anywhere else. I did a compression test and it was up to about 100 psi for the one rotation. I tried again and it was back down to 35 psi..... I ran the bike and sprayed sea foam and carb cleaner in the carb for ***** and giggles.... I pulled the plugs and the rear plug was black (plugs were new for this testing) and the front plug was new looking like outa the box. not a mark on it and definitely NOT wet. Can the intake valve be stuck closed?! kinda doubting that cause there really isn't any strange noises. Im leaning towards something sucked into the intake and is holding the valve partially open or something.... Not many miles on engine

p.s. I sprayed wd40 all around the intake and head with no changes while running


=REPOSTED IN ENGINE SECTION=


Thanks in advance!!

 

Hi from the UK and welcome to HDF. You've posted an 'engine' question in a general forum, and you will get better replies if your post again in the Evo section, where our Evo gurus live.

 

OK thanks a lot