Carb hesitation

[Cav Trooper]

I know this has probably been gone over more times than can be counted but, here goes. I had a problem with my M37 top end speed. I couldn't get over 35 to 40 mph. I checked timing and corrected then checked rpm and got 2500 max. I then bumped up the governer to 3200 and test drove. The truck would accel great but begin surging/bucking. I readjusted the gov. to the point that there was no adjustment left on the spanner nut. I then decided that I needed to remove the carb and check out the gov for basic adjustment and make sure nothing was broken etc. The carb had been rebuilt before I got the truck and the truck started and ran ok other than the lack of high end. I reset the gov. to basic spec. and while removing the carb I found a piece of black rubber stuck in the carb fuel inlet, evidently from when the PO installed an electric fuel pump and ran fuel rated hose to the carb and I think a small piece of the hose washed into the carb inlet. I think that may have been the problem with the surge as the carb may have been starved for fuel at top end. If I let off the throttle and let it idle for a couple of seconds, I could get good accel to top end then the surging would start again. When I removed the carb, I removed the intake/exhaust manifolds and cleaned every thing up and prettied the manifolds up with high temp paint. I rebuilt the heat valve and locked it in summer mode. The truck starts ok but idles a little rougher than it did before. I did not open up the carb, just adjusted the gov. When driving, in 2nd gear, when I accel to max, the truck acts like there is not throttle then revs up and chokes off again. Once I get into 3rd and 4th gears, the throttle seems to work ok on max accel. Where do I start? I have not checked the rpm yet for the gov. setting. I need another person to help with that. Mean time do I need to check elsewhere, linkage, etc. The truck was completely warmed up and at operating temp when all of this took place. I am going to check the manifold bolts tomorrow to make sure nothing is leaking, all gaskets were replaced with new of course. Also replaced the local muffler shop muffler and pipes with repro from Mid West.
Thanks,

CT

[gusbratz]

if you have been all through the carb maybe you should take a look at the points. you may have spark but it could be breaking down at higher rpms where it can't deliver enough power to make the plug spark that rapidley. I know from expierence that that dist. is very fickle so on ther other hand if it is working maybe just leave it alone.

[gusbratz]

My GL500 has CV carbs and they have never been right. I have cleaned them a bunch of times and have never been satisfied. Dips, scrubbing, vinegar, you name it. I just bought a 2.5 qt ultrasonic cleaner from Harbor freight. It was like 60$ after a 20% coupon that you can find on the web at any given moment. It kicks ***! The bike is now running perfect. Smooth, idles. Starts when cold out. The whole deal. I can’t say enough good stuff about this little cleaner.

I figure I can clean anything that will fit into it!

[Cav Trooper]

I jumped the gun on what was wrong with the carb. It turns out that after I removed and reset the governor to basic setting, I needed to adjust it, DAH!!!! I've got it just about tweeked. It's running at about 3150 rpm max and I get a little surging at cruise when I let off the gas from full throttle and hold it at about 40 mph. Charles told me I'm just about there, just a little more tweeking. I'm not sure which way to go but, with the surge still there, I will adjust in the same direction CW on the nut, maybe 1/8 turn at a time. Carb in running fine.