carbs or electrical???

[Anonymous]

My bike runs a little rough on choke, and revs up when you give it gas up to about 4-5 when it gets really rough. When you take the choke off it idles for a few seconds and dies, and if you give it gas with the choke off it dies immediately.

This may or may not be connected to the problem, but here are some other things that may be notable. The bike died oneday (becuase the charging system I payed $350 to get fixed not too long ago was never really fixed, not to mention it took them 2 months... bastards), so I charged the battery, and took it back the bike. It fired up fine, but about 5 minutes later died. And ever since the symptoms described aren't going away!

I've cleaned the carbs thorougly twice, being careful to make sure everything is in the correct setting, but it hasn't solved the problem.
The battery is good, however the spark looks a little weak, and the volatage at the coils is a bit low, but not by much (about 11V and 10V).

Before I strip apart everything and check each and every wire/grounding I was wondering if anyone has any hunches or ideas. Sounds more like a carb problem to me, but what could go wrong mechanically with the carbs (they're super clean) that would make a bike go from running to dead in a split second? Maybe a blown head gasket? Any one got ideas? HELP!!!

It's an 82 gs400 by the way

[earlfor]

Re: carbs or electrical???

I've never seen a carb problem cause a bike to die completely while out riding. Another indication of electrical cause is voltage at the coils being different. They SHOULD (whatever it is) be the same. Voltage at the coils on my 750 is within 1/10 volt of being the same as battery voltage measured at the battery terminals. I would take a multimeter and start checking to find out where your voltage is getting lost. You didnt say what you battery voltage is.

Earl


[quote="bobbyl"]
I've cleaned the carbs thorougly twice, being careful to make sure everything is in the correct setting, but it hasn't solved the problem.
The battery is good, however the spark looks a little weak, and the volatage at the coils is a bit low, but not by much (about 11V and 10V).

[argonsagas]

Well, first, you do need to do some work on the electrical connections.

If you have 10V at one coil, and 11V at the other, there is not only a voltage loss, but that is too great a variation between the coils, so there is a poor connection or two involved....and - or a poor ground.

There appears to be a timing problem, but, with it being an 1982 edition, you should have an electronic ignition.

Presuming the plug wires are on correctly, that leaves a problem in your carbs with mixture settings.

(Sorry)

When you cleaned the carbs, did you blow the idle jets clean, or just soak everything? Did you remove the mixture screws and springs?

It is common for tiny particles to get caught in these tight areas and clog them. They will not come clean by soaking. A shot of canned carb cleaner with a long nozzle will do the job.

A shot of tightly aimed compressed air will also do it, but the can is actually easier to do.

[SqDancerLynn1]

Check the voltage on the fuses If it is low at the fuse The ign switch is bad,
Best thing to do is modify the circuit for a relay to operate the on off function. Check in the forum tips/ mods section

[Don Lobacz]

Getting 11 volts at the coils may be meaningless if it's an intermittent short, and you also need to consider the ignitor side of the coil.

possible bad connections/parts:

- in the ignition switch
- in the run/stop switch
- across/in the fuses (yes, they sometimes come loose inside the tube)
- ignitor pickups
- ignitor
- coils
- any connector or wire in the above circuits
- AND the grounding side of the equation!

Intermittent shorts are probably the most elusive problem to find. Rock the switches and jiggle the wires while it is running and see if you can get it to die. Check and clean the connections if bad. Finally, you need good donor parts to substitute in order to eliminate each component.