Introduction '72 R75/5 & '66 R60/2

[Seth]

You didn’t mention the basics.
Check the points gap and valve clearances.
When they heat up, they close up.

[6bikegarage]

You didn’t mention the basics.
Check the points gap and valve clearances.
When they heat up, they close up.

I checked the points gap when I set the timing. I posted a video about doing so to you tube on my channel. While true that I haven't checked the valve clearances yet (waiting to get the nod from Frank in case he needs to get new valve cover gaskets), but it was starting and running fine (mostly fine) on both cylinders for multiple starts and a few test rides. After the longer ride (about a week and a half ago), now it doesn't want to run on the left side. There is no way the valves should conceivably change that much. I have the same compression on both cylinders. I had the carb off again last night and it is all good. mixture screw taper looks clean, cleaner give a nice spray pattern through the idle jet. The needle valve on the fuel inlet wanted to stick closed a bit, but not too bad and would fall with a bit of a tap. I had tried tapping it when starting it before and it should have had enough fuel to start on two and run for a while even if it filled and then stuck. Just to be sure, I got the pin out and cleaned the set and the stopper and it's falling out easy now. I also dropped the carb body in carb dip overnight for the heck of it. Probably won't be able to put it back together for a day or two here.

Just now I got a text giving me the nod to check valve clearance so I'll see if it yields anything.

The only other thing I can think of, is that a chunk of inner wall of the exhaust broke off and isn't allowing air flow so if the valves are fine, maybe I have to pull off the exhaust.

grumble grumble.

Thanks for the input and thoughts.

jason in Seattle

[6bikegarage]

BTW, if you are interested in checking out the video it is here: https://youtu.be/HQ3FVhqwqE0