Bike wants to die when hot
Hey y’all - I’ve got a ‘73 with points and a CV40. I took it out for a 30m to an hour ride the other day and on the way home it started to die at ant stops. No real issues otherwise. Had to take it for a sticker today and when I started up it would die after a few minutes of really good idling. Did this twice then said fuck it and hopped on, maybe not a great choice but sticker had to be done today.
Shop is about 30 minutes away on the highway and by the time I got to the shop for the sticker I had to stay on the throttle at any stop just to keep it alive - it did not want to idle. After the sticker I hop back on and it’s the same thing - heavy throttle to start it, throttle at all the lights to keep it alive. On the highway there was a bit of sneezing from the carb and popping from the pipes, but otherwise it was fine as long as I was on the throttle; no shutdowns or anything while on the highway and the power felt fine. Get off the highway and it’s the same, stopped or rolling clutched in at low speed I had to blip it to stay alive. Here are my thoughts on what to check
- Coil (I checked this in the spring when I was having starting trouble and it seemed fine, but I don’t think I’ve checked it hot yet so I’ll do that)
-Intake leak (Just replaced the O-Rings last year so it shouldn’t be leaking but I will still check them)
-Carb mix and idle (I gave it a baseline tune in the spring, it was a cold tune just to get it running but it was running well off that so I haven’t touched it)
Any other thoughts? Condenser and points seem fine, it runs perfectly at cold and warm temps it’s just when it gets really hot that it’s a problem. I’m tempted to try making it a little richer as it seems choking the carb makes the issue worse, but messing with the carb is my last choice. I’d rather make sure there’s no other issues first. Supposed to take it to a concert tomorrow so I’d really love to figure it out today.
EDIT: Cam for the points has some surface rust that’s wearing the points arm way fast - the gap changed while I was riding and that’s probably what caused it. Going to fix that and update after
EDIT 2: I was able to re-gap the points to spec and it didn’t change anything much, still died after a few minutes. Figured I should rule out vapor lock in the lines and bought a length of fuel hose, re-routed it from between the jugs to behind the frame (on top of the oil pan) and it rode perfectly for an hour. Granted, it was 75F instead of 100F so we’ll see how it does in the heat tomorrow, but good so far! Thanks for the help folks