Cold starting problem

coffeeman · 02-10-2009, 2:42 PM

I have a 1978 gs750 that takes forever to start when cold once its warmed up no problem. I dont know where to start to fix.

bladeracer · 02-11-2009, 4:04 AM

Are you using the choke circuit?

coffeeman · 02-11-2009, 7:38 AM

Yes i use the choke and it is in working conduction. If i turn choke off to soon the bike will stall. Throttle response is also poor when cold.

bladeracer · 02-11-2009, 7:49 AM

Stalling and poor response is normal for a cold engine without the choke (because the fuel tends to bead on the cold metal of the intake tracts instead of atomising with the air and thus is way too lean for combustion).
It shouldn't need any throttle at start up with the choke engaged. Opening the throttle will lean it off even further.

How long has it been playing up?

coffeeman · 02-11-2009, 8:47 AM

I just got the bike in Nov the seller said its been happing all of fall. Even with out the throttle it takes 7 or 8 long attempts to the point of almost killing the battery. Also no smell of gas during starting attempts.

bladeracer · 02-11-2009, 9:01 AM

If it's been sitting for some time, the idle and choke circuits of the carbs may be clogged up. If you can reach the airbox intake you could try blocking most of it off with your hand and see if that helps. It's much more likely that it's starving for fuel (assuming the carb circuits are blocked) but less air might improve the mixture enough to start it, although it really would need more fuel.
It quite likely could use fresh plugs as well.

coffeeman · 02-11-2009, 9:12 AM

I will try all that you said and and see what happens. Thanks for the info.