GS850 hard electric starting

[brendanGS850]

1979 GS850, I have recently done: adjusted valves; replaced all engine gaskets; intake o-rings; resealed airbox. It is running way better than before but still chasing one particular issue.

The issue is the bike is hard to start when it is cold out, but only when using electric starter. It will turn and turn, but if I kick it it will usually start on second or third kick.

Once it has started once this way it will usually fire right back up using electric or kick start.

It seems to be related to outside air temparature; it is worse below ~50 degrees F.

I am thinking battery issue? Other possibilities?

[tkent02]

There is not enough power to run the ignition while the starter is cranking, so the voltage to the coils drops to a low enough value that the ignition stops sparking. This is fairly common. Look for corrosion somewhere in the wiring, or just an old or weak battery. The fact that it is temperature related may point to the battery.
It could also be a weak old starter drawing too much current, but this is not likely, the starters usually work fine forever.

[49er]

First check your battery voltage level after you have given the bike a decent run. It should read well over 13 volts if checked right after you turn the engine off.

If the battery voltage checks out ok, you will likely find that the problem lies within the starter, or it's associated wiring. I recently overhauled my '79 850's starter after it failed. I had previously renewed all the stator and starter connections and ran extra earthing points, but still had a poorly performing starter, when the engine was cold. It was particularly bad during winter, after the bike had sat for more than a week between runs. Having a kick starter as a back up, delayed the need for a starter overhaul.

When servicing the starter, make sure that you clean all the brush connections thoroughly and descale the steel fields with glass paper. My fields were heavily oxidised and responded great after cleaning. The armature needs a light clean up with glass paper where the brushes make contact. Also , the cut grooves need to be cleared of any carbon/scale buildup. Fit new brushes with tight connections. Lightly lube the bushes during re-assembly.

I was pleasantly surprised how powerful my starter was after the rebuild. I had put it's poor performance down to the higher than stock compression I was running, but now I don't get kick back when starting the engine from cold.

I think many starter overhauls aren't thorough enough to gain a good result. Just replacing the worn brushes is only half the equation.

[SqDancerLynn1]

A 79 First check the battery voltage Then check the Voltage at the fuse block Should be very close to the same !!! If there is a voltage drop ? Check the ign switch ! It could also have a weak battery . Good enough to crank the motor but not enough voltage to give it good spark. I had a 78GS1000 like that I could crank it for 5 minutes and it wouldn't start I replaced the 14ah battery actually with a 12ah battery and it started fine after that. Another thing you could try is to prime the carbs = turn the petcock to prime for 5 seconds before trying to start it.. Make sure to give it full choke and do not touch the throttle