VM 28 Carbs idle issues.

[Octane80]

Hey guys I have a 77 gs750 with pods, 4-1 and vm28 carbs from a mid 70's kz. I have thoroughly cleaned the carbs and blasted all the orifices with cleaner along with replacing boot rings and all o-rings within the carbs. I have also rebuilt the petcock and fuel flows fine from it. The engine has two idle points, I can start it and get it set at 1100 ish but after a little riding it will rise to up around 2000 and hang there. Sometimes it comes back down and other times it just sits at 2k. The bike also has dyna S ignition and I just set the timing according to the manual. The motor runs pretty good and really the only issue I've noticed is a bit of bog when you crack the throttle, but that appears to be normal for the bike. I've also synced the carbs, and the last thing I have left on the list is to check the valves. Could this be due to bad valve clearance? The motor has 16000 miles and it sat a good deal before I purchased it and did the rebuild. I also have checked the plugs and they seem to be a decent color, maybe a tad rich but not to the point I would have to worry about fouling. The only other issue I've noticed is during choke the engine runs super rich to the point that the exhaust is sooty. Thanks in advance for your help!

[BassCliff]

Hi,

Sticky cables? Still a little lean? Have you done plug chops?


Thank you for your indulgence,

BassCliff

[Octane80]

Thanks BassCliff for the reply! I figured out the idle issue and it ended up that the throttle pull cable was being kept at a weird angle in the perch and was binding a bit because of it.

However, now I have a new issue which is consistent and began just recently. Upon acceleration the engine begins to miss a bit at 5k rpms, I've checked spark on all the plugs and I'm getting a good blue spark on all cylinders. I also have replaced plugs and checked for air leaks. Coil voltage stays over 13.5 volts and gas is flowing fine.

I did notice that a couple of the plug wires were getting some cracks in them and put my hand up to them to see if I would get zapped but did not. Could it be the plug wires? I'm low on cash so I'm trying to avoid replacing the coil plug units, has anyone tried to replace the plug wires? I assume that since the coils appear to be potted this would not be doable, but it's worth asking I guess.