SSA Sierra Sportbike Association | Reno Nevada Motorcycle Trackday Weekend Riding Club

General Chat - Weekly Rides, Bike Discussion, & More . . . => The Garage => Topic started by: vx800 on September 16, 2015, 04:37:45 PM

Title: HI ! carb help !
Post by: vx800 on September 16, 2015, 04:37:45 PM
 :-\   I tried to ride this bike the other day..... just not hapnin ! So !  I want to go through the carbs and could use some support.  Anyone around who knows about carbs .... well feel free to get in touch. 
Title: Re: HI ! carb help !
Post by: GreenMachine on September 17, 2015, 08:44:25 AM
Carbs are easy if you have access to their standard (OEM) settings, like from a repair manual or user forum. 
Title: Re: HI ! carb help !
Post by: dub on September 17, 2015, 02:54:38 PM
What is it doing or not doing?
Title: Re: HI ! carb help !
Post by: vx800 on September 17, 2015, 03:54:54 PM
Hi  ! DUB
I will not rev and pull past about 5500 rpm.  thought it might have been sitting and needs to be cleaned.  maybe the high speed ports are clogged.  I dont know.  joe 214 392 4005
Title: Re: HI ! carb help !
Post by: dub on September 17, 2015, 07:07:02 PM
Yeah, a clogged main jet would show itself at wide open throttle, so that seems like a good guess.

The easiest thing to try first would just be to clean it. Track down the factory service manual and it will tell you what to do, step by step. Carburetors aren't black magic, it's all just held together with nuts and bolts.
Title: Re: HI ! carb help !
Post by: vx800 on September 17, 2015, 08:16:12 PM
good idea !   thanks ill try that! 
Title: Re: HI ! carb help !
Post by: cobra23 on September 17, 2015, 09:47:51 PM
Those are CV (constant velocity) carbs.

Often there is a vacuum leak somewhere, which will cause a malfunction. Cleaning them is good, be very careful while pulling the rubber diaphragm off the top. They tear easily. At low vacuum the throttle slides are held down to increase velocity, and burn cleaner. At higher vacuum the slide is allowed to fully open. It sounds like the slides are not fully opening.

The pilot jet plugs first, which will cause a very strange miss at smaller throttle openings, then run good at full throttle.

You may find that after cleaning them they still malfunction, if that is the case don't panic. Look for loose vacuum lines such as the vacuum operated petcock.
Title: Re: HI ! carb help !
Post by: vx800 on September 18, 2015, 08:11:50 AM
Hi !  thanks Cobra .... I will be replacing some vac hose.  this bike is 26 yrs old .... I am sure the rubber is getting bad. 8)
Title: Re: HI ! carb help !
Post by: cobra23 on September 22, 2015, 10:46:56 PM
Don't forget to wear proper protective clothing, and extinguish all sources of combustion when working on the fuel system.
Title: Re: HI ! carb help !
Post by: vx800 on October 12, 2015, 06:17:34 PM
thanks !!!! its back  together and I am riding it for awhile before I do the clutches  and  doing front fork seal .....  8)