Low power at low rpms

[Skateguy50]

OK, here is my issue thats been on and off a week or so, but could say forever for me since Im just getting the bike running again.

Some days, typically colder or rainy, the bike has more issues than others running it low rpms and getting any power to the wheel. Basically if I want to move out of first I need to keep the throttle revved around 5-6k just or else the power just drops as soon as I ease out of the clutch.

Now, I already cleaned the carbs and put in new orings and new jets (they physically broke). I also did the oring at the intakes, that helped a bit but not fully.

Also here are some issues that might be related, I cant get the bike to run on idle using the idle adjust knob on the carbs. If I adjust the idle on that and back off the adjustment on the cable to leave a bit of slack it runs ok but cant start it once its off. In order to start it cold I need the adjustment on the carbs set back so the butterfly valves can shut fully.

I think that might be related to having some slack left on the choke and not having it fully choked so was gonna adjust the cable to allow it to go full.

Then the "air/fuel/whatever it is adjustment screws" I started with just tight then 1 1/2 turns back, i tried more, i tried less, i tried all the way tight... still not sure where it should be cause none seem to make any differance.

I only bench synced the carbs but it sounds ok enough... if you think that is the issue I could try to find someone with the manometer to do it now.

So yea ask more questions and any advice you have is welcome.

[earlfor]

Check the compression. Without compression, you can not have fuel induction. Check the valve clearances. If the valves are not closing fully, you cant have compression. If both of those are OK, check the ignition timing with a timing light. Check voltage level on the orange/white wires that supply power to the coils. It should be close to the same voltage measured at the battery terminals. (unplug the wires from the coils to check voltage)
If you have low voltage, it isnt going to run worth a crap either. :-)
If your battery is not holding a minimum of 12.5 volts, I would replace it as low system voltage makes low speed running terrible because the stator at idle rpm is not outputting enough amperage to make up the difference.

Did you completely disassemble and dip the carb bodies when you cleaned them? Spray cans of carb cleaner are worse than useless for cleaning carbs and should only be used as paper weights in the shop or for removing grease spots on the floor.

A vacuum carb synch is required. The purpose of a "manual synch" is only to get the carbs within a range that will allow the engine to start so that a running, proper carb synch can be done. I cannot, and have never met anyone that could accurately synch a rack of carbs manually.

Earl

[spyug]

Bike type and mileage would be helpful guys. Do you know when the last valve adjustment was done?

If unknown I would opt for doing that first then following through with everything Earl suggests. It sounds, to me, a lot like faulty induction and incorrectly set carbs. a two pronged problem.

Check things over and let us know what you find.

Good luck with it.
Spyug

[Skateguy50]

sorry its a 83 gs650 with 18k miles on it...

The battery is new, plugs are new, and some other basic stuff has been done. I am completely new to working on carbs and hesitant to go to far ahead of what I think I can do so no I didnt dip the carbs when I went through them.

Im hesitant to go past the carbs till that is sorted out, as again I dont like to make more problems than im solving so wont touch the engine and timing and such yet.

thanks for the suggestions, now I need to get some carb dip and take off of work early so I can ride tomorrow... to nice of a day not to get this done.

[Skateguy50]

follow up for those interested.

Bike runs great now, I made myself a homemade manometer based on a thread I read here. Not perfect but worked good enough, and got the carbs balanced at least better than they where.

Also I replaced the vacuum line from the carbs to the gas tank, I previously did the fuel line but the hardware store was out of the size needed for the vacuum.

So it was on of them or a combination, but starts up good, holds and idle, and most importantly has power and runs much better.