1978 GS750 idle circuit problems.

[Guest]

Hi folks.
I've just bought a 78 GS750.
Starts and idles but cuts out with a pop when you open the throttle quickly.
If you bring the revs in gently it stutters slightly until it comes onto the needle and then runs fine.
The carbs were stripped refurbed and cleaned by the previous owner.
Any ideas?

[hannibal]

Welcome!

Time to clean the carbs thoroughly. You can find a guide here: http://members.dslextreme.com/users/...rb_rebuild.pdf

[allojohn]

Yep, carbs were not properly stripped, refurbed and cleaned by the PO. You cannot trust anything the PO tells you, unless he's your brother and maybe not even then....

[markla]

If as said the carbs have been cleaned already may be change/clean spark plugs do you know if the bike has electronic ignition or points timing if points then check the timing before stripping carbs for a second time.

Just throwing that in i had dodgy plugs bike runs sweet now.

[Repatriot]

If as said the carbs have been cleaned already may be change/clean spark plugs do you know if the bike has electronic ignition or points timing if points then check the timing before stripping carbs for a second time.

Just throwing that in i had dodgy plugs bike runs sweet now.

Thanks for that.
I'll try new plugs and check the timing before I redo the carbs.
Bloke who so,d me the bike is sound.
He had them ultrasonic cleaned and admitted he was scratching his head over the stalling.
He thought it might be the mixture screws.
No biggy if I have to clean them again.

[uk gs nut]

Check the bottom mixture screws are set right, about 1 turn out from lightly screwed all way in. Carefully the tips of those screws snap off easy.