Author Topic: Idle speed more than doubles once bike is warmed up  (Read 641 times)

0 Members and 1 Guest are viewing this topic.

Offline Scott

  • 72 CB750
  • Expert
  • ****
  • Posts: 833
Idle speed more than doubles once bike is warmed up
« on: April 18, 2013, 09:54:12 PM »
Hello there
I have a CB750 K2.
I've done a bit of work on the bike such as carby kits including new jets and needle and double checked the float height.(I did move the clip on the needle down one notch)
New carby rubbers and clamps, new K&N air filter and air box rubber seal.
New throttle cables.
The bike starts up fine from cold and idles at about 900 to 1000 RPM ( going off the bikes tacho).  Then after about 5 to 10 minutes riding the idle goes up to over 2000 RPM

Any sugestions or thoughts at all will be appreciated
Scott

Offline bryanj

  • Really Old Timer ...
  • *******
  • Posts: 14,158
  • CB500 Number 1000036
Re: Idle speed more than doubles once bike is warmed up
« Reply #1 on: April 18, 2013, 11:15:49 PM »
You have the tickover set too kigh, set it to about 1100 when hot and hold the throttle open a touch when cold
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 20,277
  • Saver of unloved motorcycles.
Re: Idle speed more than doubles once bike is warmed up
« Reply #2 on: April 18, 2013, 11:36:54 PM »
float valve not working properly and/or vacuum leak.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Scott

  • 72 CB750
  • Expert
  • ****
  • Posts: 833
Re: Idle speed more than doubles once bike is warmed up
« Reply #3 on: April 18, 2013, 11:44:55 PM »
cool thanks and thanks
I'll go do that now and check for leaks just incase
Have a good one
Scott

Offline Scott

  • 72 CB750
  • Expert
  • ****
  • Posts: 833
Re: Idle speed more than doubles once bike is warmed up
« Reply #4 on: April 19, 2013, 03:33:57 AM »
Thanks mate all good