What causes

[mack]

a slight intermitten popping when gearing down. Only comes on some times and only from 3 to 2 and down to first. Been a long time, 7 weeks since I had the LH running and riding. Very smooth and strong going up in gears but I noticed this popping from the left exhaust. Took her back home and tightened the exhaust flanges, spark plugs and put some sea foam in her then took her out again. Still doing it. Supposed to rain most of the week so I'll pull the carbs out so I can retighten the intake manifolds. I know my valves are seated properly and shimmed correctly although the exhausts are at the minimum clearance, but I read someplace on here that there had been a change and that the tolerance was lowered. The last time I had her out in March, this popping was not present. Any idea's are welcome.

[James England]

It's usually too weak a mixture on the carbs. If you richen the mixture screws it will most probaab;y disappear. It did on mine.....

[BA80]

+1.....carb adjustment. You might ride it a while and see if it clears up. Might just be having a hard time coming out of hibernation.

[mack]

Ya your probably

right. I had the hockey game on in the shop and between periods I pulled the plugs and had a look. 1,2 &3 looked lean to me and 4 was border line. I also took the time to tighten the manifolds for 1 &4. Got almost a half turn on them so the carbs will be coming out to tighten 2 & 3. I'll do that then go for a ride to see if that what made it lean. Not surprised that I have to do it, I just thought I would have to put more miles on it before I had to retorque everything. I wrote down my shim clearances when I put it back together and all the exhausts are at 0.21 mm. I'm considering just changing them all out. Even if they're over it will give me a few seasons of riding before I have to worry again.