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Main Area => General GS500 Discussion => Topic started by: MMYT on April 30, 2014, 10:43:23 AM

Title: Fuel suffocation problem.
Post by: MMYT on April 30, 2014, 10:43:23 AM
i have recently purchased 2001 gs-500. It has the following problem
As i ride it at about 4k or higher rpm for about ten minutes, inline fuel filter is emptied and after further such travel the bike dies down.
Fuel filter do no fill up unless carb side pipe is taken off or bike left standing with engine shut off for about half an hour, after wards bike starts and runs normally.
There is no change in problem whether i keep fuel tank cap open or closed.
Previous owner had blocked vacuum system from both carburetor and petcock and had hole cut through petcock diaphragm and it remains as such.
i have rebuilt carbs with K&N kit since purchase.
kindly suggest remedy.
Cheers.
Title: Re: Fuel suffocation problem.
Post by: Br4denJ on April 30, 2014, 10:50:47 AM
Is there a block in the petcock where the PO cut a hole in the diaphragm?  I would get rid of the frame mounted petcock and convert to a gravity fed system.  There is a thread on this site on how to do it. 

I don't know if you have considered it but is the float hight correct?
Title: Re: Fuel suffocation problem.
Post by: BockinBboy on April 30, 2014, 10:56:04 AM
Remove inline fuel filter.  The tank petcock has a screen filter which should be sufficient enough on its own.  If you really feel the filter must be there, you must make sure they are for gravity fed motorcycle lines.  Your typical inline filter is too restrictive.

Use something like this, only if you MUST
(http://cgi.stanford.edu/~sanjayd/gs500/uploads/Upgrades/filter.jpg)

Do not use a regular one you might find on something like your mower
(http://www.hoses.co.uk/images/P20385811.jpg)

- Bboy
Title: Re: Fuel suffocation problem.
Post by: MMYT on April 30, 2014, 11:19:54 AM
At present i have installed the following filter (normally found in 1000cc cars)


[attachment deleted by admin]
Title: Re: Fuel suffocation problem.
Post by: BockinBboy on April 30, 2014, 11:39:52 AM
That looks like the one we used to have on our old Mercury outboard motor (boat)... which was a paper-type filter inside.  If that indeed is a paper-type inside there, those are the type you want to avoid because they are too restrictive for this application.

- Bboy
Title: Re: Fuel suffocation problem.
Post by: MMYT on April 30, 2014, 12:11:01 PM
It has some foamy material filter core.
Title: Re: Fuel suffocation problem.
Post by: BockinBboy on April 30, 2014, 12:13:47 PM
Not being filter guru or anything, I would just try it without just to see if it your issue improves.  Its a simple enough thing to add or reverse, so shouldn't be too hard to rule out.

- Bboy
Title: Re: Fuel suffocation problem.
Post by: radodrill on April 30, 2014, 03:00:36 PM
1) Get rid of any inline fuel filters; the one on the tank petcock is enough.

2) holes in the diaphragms will not let the carbs work right; replace them ASAP.

3) you need a vacuum line from one of the carburetor bodies to the frame petcock; this allows fuel to run through the petcock when the engine is running (with no vacuum fuel only flows in the prime position).