16-01-20, 07:53 PM
If the revs are staying high since you took out the carbs I'd be thinking the carbs might not be seated fully and there might be a vacuum leak. You could spray some wd40 around the intake area and listen for a change in revs. I'd also check that the throttle cable is routed correctly, that it's not adjusted too tight and that it snaps back properly when you release the grip. Also check that the choke plungers are all returning properly.
I'd agree with bazza the ht caps are a possible problem. They're a common failure and can cause a misfire. You could try spraying some water around the caps while the bike is running and listen if the engine stumbles. You can also run the bike in the dark and look for arcing. Another trick is put water on the exhaust headers and see if one header dries slower than the rest, that can show a cylinder that's not running properly. The ngks caps are very cheap so worth replacing anyway.
If the bike has been running badly for a good while I'd take out the spark plugs and inspect them, clean them off and see if that helps. If they're very bad I'd replace them. I haven't had TPS problems so I'm not sure what symptoms from that are but I know darrsi has had trouble with his so it's worth checking if he says so. Another possibility, Red98 had serious problems trying to solve a stutter, he rebuilt half the bike trying to find fix it and it turned out to be a bad reg/rec so that could be worth checking.
I'd start by ruling out those problems one at a time because they're the easiest. If you're confident all those things are good then look at the carbs. As a quick test on the carbs you could try leaving the choke on a bit and ride the bike. If the symptoms improve then it would point to the problem being a lack of fuel from the carbs.
I'd agree with bazza the ht caps are a possible problem. They're a common failure and can cause a misfire. You could try spraying some water around the caps while the bike is running and listen if the engine stumbles. You can also run the bike in the dark and look for arcing. Another trick is put water on the exhaust headers and see if one header dries slower than the rest, that can show a cylinder that's not running properly. The ngks caps are very cheap so worth replacing anyway.
If the bike has been running badly for a good while I'd take out the spark plugs and inspect them, clean them off and see if that helps. If they're very bad I'd replace them. I haven't had TPS problems so I'm not sure what symptoms from that are but I know darrsi has had trouble with his so it's worth checking if he says so. Another possibility, Red98 had serious problems trying to solve a stutter, he rebuilt half the bike trying to find fix it and it turned out to be a bad reg/rec so that could be worth checking.
I'd start by ruling out those problems one at a time because they're the easiest. If you're confident all those things are good then look at the carbs. As a quick test on the carbs you could try leaving the choke on a bit and ride the bike. If the symptoms improve then it would point to the problem being a lack of fuel from the carbs.