84 VF700c Magna Carb problem

 I bought a 84 VF700c Magna from a guy who let it sit (without proper
prep) in his garage for 12 years. After going through and changing
plugs, *all* fluids and battery I cleaned out the carbs, put them back
in and the bike ran like new...for about 200 miles. Then, while on the
highway one afternoon the bike started to bog and the throttle got
sticky. It will idle (barely) but boggs when given gas. I took the
carbs back off and there is a sticky dark brown residue through most
of the middle of the carb and throttle plates. I'm guessing the
bogging was a result of this stuff gumming up the carbs and I'm in the
process of re-cleaning the carbs, but would like to know if anyone
might have an idea of what caused this. I'm worried that just cleaning
out the carbs will only temporarily fix the problem. Also note - I did
install a new fuel filter before all this happened. I have not had the
gas tank(s) cleaned. Ideas? I've posted a picture of one of the
'gummed up' carb throttle plates here:
http://www.dontcamerame.com/Gallery2/main.php?g2_view=core.ShowItem&g2_itemId 495

 

And anything between the tank and the carbs too, including ANOTHER new fuel
filter.
It should be a "micro-screen" type (ceramic?) instead of just a screen.
Then when you think everything is clean and it is running again, put some
carb cleaner in the gas for a  few tankfulls.

Good luck!

 mike_r_harmon@yahoo.com wrote:

Some of the crud in the fuel system moved into the pilot jet and the idle
mixture passages.

CV carbs run off the idle circuits 95% of the time and the ports and passages
are very tiny and easily plugged up.


That's true. You either have to ride a motorcycle with CV carbs often so the
alcohol additives in fresh gasoline will keep them clean inside, or you have
to add some Berryman B12 every few months.

If you don't do that, you'll have to remove the carbs and spritiz them out
with aerosol B12.

--
Message posted via MotorcycleKB.com
http://www.motorcyclekb.com/Uwe/Forums.aspx/bike/200708/1

 mike_r_harmon@yahoo.com wrote:

http://www.dontcamerame.com/Gallery2/main.php?g2_view=core.ShowItem&g2_itemId 495

Got any pictures of the airbox side of the carbs?

Besides cleaning out the tank, look inside the airbox.  Clean
out the condensate trap, too.  Was any sort of sealant used
anywhere on the airbox or the intake boots?  If so, it could
have dissolved and led to the sort of deposits you're seeing
there.

http://www.visi.com/~olsonm/img_0889.jpg

--
'01 SV650S  '99 EX250-F13  '98 ZG1000-A13
OMF #7