New purchase. Carb issues.

View previous topic View next topic Go down

New purchase. Carb issues.

Post  R056rx on Thu Nov 21, 2013 6:32 pm

PO said the bike had been serviced 2 years ago, including valves checked. He also fitted a FMF Q4 tail pipe and FMF headers. He said it's been ridden for two hours since and ran fine. Just before it was advertised he had the carb cleaned and refilled the tank with new fuel, and it was started the day before I saw it.
When I viewed it he had trouble starting it, but it did start eventually, but the idle was high. He lowered it with the throttle stop knob but when the throttle was blipped the revs would rise again. After 3 or 4 adjustments the revs settled.
I then test rode it and everything was great.
I bought it and rode about 50 miles home. As it warmed up the revs at idle increased again. I decreased them with the throttle stop knob again and all was fine.
When I got it home I noticed a dribble of fuel from the drain pipe. I think I solved this because the drain screw was a quarter of a turn out.
I also noticed the pilot screw was only 1/2 a turn out.
I turned it out to 1 and 3/4 turns and turned the throttle stop knob to raise the revs again.
I got it started in 2 or 3 kicks (3 kicks with de-com lever in, full choke, TDC, lever in, push past TDC, lever out, big kick) but it dies and then I have to go through the flooding procedure and start again. It will start eventually but pops out the exhaust on the over-run.
I've also noticed that no matter how far out I turn the pilot screw the revs don't die.
I know I need to take the carb apart and give it a good clean and to check to see what pilot jet I've got.
I've also got to check the valve clearance and clean the air filter.
I thought that high revving at idle would be explained by too lean mixture, especially since the pilot screw was only half a turn out. Also the fact that the idle doesn't die no matter how far out I turn the pilot screw could also mean too lean. But over excessive popping on the over run I thought points to too rich?
I'm thinking maybe the FMF exhaust has upset the standard jetting, and whoever cleaned the carb didn't set it back up properly.
Anything else I should be looking at once I've got the carb apart?
avatar
R056rx
XRR Jockey

Joined : 2013-11-16

Posts : 82
Location : Winchester
XR650R Year : 2002

Back to top Go down

Re: New purchase. Carb issues.

Post  Mad Frosty on Thu Nov 21, 2013 10:56 pm

Two sizes up on the main jet its the norm , but not the absolute rule with complete aftermarket exhaust system .
avatar
Mad Frosty
XRR Monger

Joined : 2012-11-26

Posts : 1179
Location : UK
XR650R Year : 2000

Back to top Go down

Re: New purchase. Carb issues.

Post  SkidMark on Fri Nov 22, 2013 7:26 pm

Hi,

download a copy of the service manual and check everything they tell you too in there.  as frosty said you will need to change the jetting for an aftermarket exhaust normally.  Note that when you set the float level set it 1mm higher (17mm?) than the book says.

Its a really easy carb to work on - enjoy!  (although I'm still trying to figure out what all the hoses are coming off it Rolling Eyes  )

SkidMark
avatar
SkidMark
XRR Freak

Joined : 2012-05-16

Posts : 320
Location : Liberia
XR650R Year : 2005

Back to top Go down

Re: New purchase. Carb issues.

Post  AURORA on Sun Nov 24, 2013 8:55 am

Float height not set to proper height.
Float valve not replaced when the carb was rebuilt.listen up
avatar
AURORA
XRR Freak

Joined : 2008-12-09

Posts : 689
Location : PHOENIX
XR650R Year : 2003

Back to top Go down

Re: New purchase. Carb issues.

Post  R056rx on Tue Nov 26, 2013 8:53 pm

Thanks guys 2 thumbs Looking forward to a warm weekend so I can get out in the (unheated) garage and start striping it down.
avatar
R056rx
XRR Jockey

Joined : 2013-11-16

Posts : 82
Location : Winchester
XR650R Year : 2002

Back to top Go down

Re: New purchase. Carb issues.

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum