idle/weird issue?

[skubasteve!]

Bike starts great, idles fine around 1100 or so. Go for a ride and when in neutral at a stop it still at 1100 or so, but when I pull the clutch in and put it into first (clutch still in all the way not engaging at all) it idles at around 2k... this was after riding for a bit.

The bike rode amazing and pulled well in all gears through the rpms, and only had issues of it almost putting out, and having a little trouble leaving from stops..

Any ideas? I have done all the "catch up" maintenance.

Thanks

Steve

 

[Nessism]

What bike?

 

[skubasteve!]

78 gs750 its in my sig.

 

[Nessism]

Oh geeze. My bad.

Did you replace the intake boot O-rings? An air leak will lead to a hanging idle.

 

[skubasteve!]

Yup and the boots themselves, new airbox boots too.

 

[Nessism]

When you went though the carbs did you make sure all the fuel screw tips were intact and not stuck in the carb passage? Where are the fuel and air screws set? What I'm driving at is you might want to richen up the idle mixture some, either open fuel screw or close air screw.

Good luck

 

[skubasteve!]

Thanks for the help nessism chef did my carbs for me early this year.... I had them synced up once the bike was all put back together. Could it by chance have something to do with the points/condensers?

 

[Nessism]

No disrespect to Bill, but the carbs need to be tuned on the bike.

I suggest you try opening the fuel screw another 1/8 turn. They are on the bottom of the carbs and difficult to reach but it can be done with a stubby screwdriver. Alternately, maybe try turning in the air screw a 1/4 turn. One way or another the idle mixture needs to be made richer. I doubt the points are the cause but it goes without saying that you should make everything on your bike is in proper running order. If the points need attention, do it.

 

[trippivot]

fine idle when cold? fine idle when hot?

but pull the clutch and put in gear and it goes up 1K ?? they are not related nor interactive

lube and check the routing of the throttle cables ... try this;


get it running and idling constantly trans. in neutral (no clutch) sit on the bike without the kick stand

turn the bars fully to the left steering stop. then fully to the right steering stop. is the idle ok or does the problem arise?

next..

do the same steering test with the clutch lever pulled in fully to the bar

what does it do? same or change?

 

[hampshirehog]

Sounds to me as if it's as simple as the clutch cable moving and snagging the throttle cable (or the carbs somewhere else). Pull the tank and have a look what moves when you pull in the clutch lever.

 

[skubasteve!]

fine idle when cold? Fine idle when hot?

idle seems fine when cold, and it actually felt better to leave from a stop when cold, once warmed the idle seemed to go up a bit, and it was harder to leave from stop.


but pull the clutch and put in gear and it goes up 1k ?? They are not related nor interactive
yes, only once warmed i believe, havnt had the chance to try again

lube and check the routing of the throttle cables ... Try this;
will do

get it running and idling constantly trans. In neutral (no clutch) sit on the bike without the kick stand

turn the bars fully to the left steering stop. Then fully to the right steering stop. Is the idle ok or does the problem arise?
tried tonight when it was cold and no difference, will have to try it again once its warmed up..

next..

Do the same steering test with the clutch lever pulled in fully to the bar

what does it do? Same or change?
nothing when cold, but again will have to try once its warmed up (tomorrow hopefully)

thanks for the help guys!