Hey guys. I have a little problem with a mid range surge/stumble, and hope you all might be of some help.
I have re-done the carbs, installed the proper jets, new points, plugs, filters, fuel line and rebuilt the petcock. It idles like a dream, has plenty of power up to about 5000 rpm's and then starts to stumble and doesn't seem to want to go. Back it back down to around 4000 rpm's and it runs perfect. It seems to do it when it's warm.
I have not changed the condensers, checked the timing, adjusted the cam chain or adjusted the valves.
I do have a touchy key switch that has a connection problem. It died on me on the way to church, losing all electrical power. I fiddled with the wires behind the switch and it started back up. It's done that one other time to me. So I also wonder if the stumble isn't caused by the poor electrical connection at that RPM where maybe it has just the right vibration?
I read a saying years ago that went like this; "90% of all carb problems are electrical." And it sure appears to be carburation, on the surface. But the carbs were meticulously cleaned and rebuilt, everything works as it should.
So what do you guys think?
Oh and one other thing, what do you do about a throttle hand that goes to sleep after only 15 minutes of riding. I do not have this problem with my HD Road King
I had this same problem with my 1973 cl350, that range is controled by the primary main jet. I had a number 70 and went to a 72 that has solved the problem and it has good acceleration through the rpm range with no hesitation.
I found timing with a timing light more accurate than static timing. I had what I thought was carb problems turned out one of the coils was malfunctioning when the engine warmed up. Also make sure the valves are set correctly.