rpm's changing

[Zach]

hey everyone, finally got the bike back together and rode it for a bit the

other day. Starts up beautifully, rpm is around 2,000 initially, warms up and

drops to about 1300... After riding for about a half hour, I noticed that the

rpm's stayed at 2,000 and wouldn't drop... is this normal? Advice/what to

look for or do? I'm hoping it's something simple.. Zach

 

[tkent02]

Adjust the idle when hot. Help it a little with the throttle when it's still cold.

 

[Zach]

Thanks! I appreciate your help

 

[Zach]

after more riding and adjusting the idle when hot, it still likes to hang at the 2,000rpm range occasionally going to the 3,000 range... after a quick blip of the throttle it comes back down. Initially this led me to believe I was running lean on the pilot circuit so I went up one size on the pilot jets. The pilot air screws appear to have a very small variance on the rpms... any further suggestions?

 

[tom203]

Yeah, it's likely lean (at times) causing hanging idle-maybe air leak at carb boot/head interface- have you replaced the gaskets here ? how do your carb boots look?

http://www.alpha-sports.com/spst/1977 GS400X/01.htm?q=suzuki-parts

 

[Zach]

replaced with brand new boots, o-rings, and gaskets where carbs meet the block.... anything I'm missing?

 

[tkent02]

Stock air box, and is it sealed well? CArbs all synched up and adjusted properly including the floats? Just guessing here, I know nothing about how the twins run. (Mine doesn't)

 

[Zach]

I have pods on... but supposedly they're the cheap kind which restrict a large amount of air very similar to the air box. Floats are good... To my knowledge there are no leaks from the boots... Went for a short ride today and at start up, the throttle opened and closed extremely easily. After riding for about 20 minutes, this was no longer the case. I found that it was as springy as it was when I first started riding and I'm currently thinking this is what is making the rpms run high at times. Is there a correct procedure for adjusting the throttle cables? I searched through my clymer but was unable to find a procedure.

 

[Nessism]

I have pods on...

There you have it...:-\\\

Mixture too lean, leaking some air maybe, who knows?

 

[Wallowgreen]

Is there a correct procedure for adjusting the throttle cables? I searched through my clymer but was unable to find a procedure.

https://onedrive.live.com/view.aspx?resid=2370B62DDF9F0C6B!1334&app=WordPdf&authkey=!APM7hx6Q2ynLu-A

Chapter 3 page 40

 

[Zach]

I installed the next size up pilot jets... perhaps I have to go another size up to richen it... Thanks for finding that in the manual... I think I've looked at that before just thought there would be something else to it... I guess I'll report back in a bit after attempting to track down a possible air leak and further adjusting air/fuel mixtures

 

[Zach]

Finally had some time to work on the bike... I lubricated the throttle cable and was amazed at the difference... Adjusted the throttle cable and I'm currently 98% sure that the throttle cable was causing the higher idle... I also found that my carbs normal air mixture screw is supposed to b at 1 1/4 turns out. Messed around with the adjustment and I got it running extremely well. All in all it was a good day

 

[steve murdoch]

Improper throttle cable routing can cause the revs to hang up and seeing the Clubmans on your bike you may have to fiddle withthe way you thread the cables.

 

[Zach]

that was exactly the issue steve, rerouted the wires and the problem appears to have disappeared. Now, onto fix the speedo drive unit.