GV650 carb. No Mo-jo

[Craig J]

My Carb Gv650, has suddenly lost all it’s go. It will start and idle fine, but is struggling to get much past 40, with no pull all.

From what I can tell the sparks are ok, so I am thinking could it be blocked main jets on the carbs or is it more likely some sort of problem with the fuel pump ? The filter is nice and clean.

[Alan McLean]

Hi Craig, It doesn’t sound like a main jet problem to me as that would normally be a gradual process. If you have spark and fuel going to the carb’s I would be checking for a vacuum leak.

[Craig J]

Thanks. Does the fuel pump run off a vacuum ?

[Alan McLean]

Yes the fuel pump run’s on vacuum, you need to check all the vacuum lines for cracks/splits and especially the inlet manifolds for the same.

[♠️ M77]

It may sound silly to ask, but i hope you have been using E5 fuel havent you?
E10 fuel in this country is doing no one any favours even the most efficient injected cars / bikes do better on E5.

Also , if the filter is very clean (zero particles) , the tank isn’t rusty (phewww)

Go to halfords and buy WYNNS GOLD PETROL CLEANER.  Pour the whole bottle per 2/4 full tank. Ride until the bike is low.

Let us know if the “soft-clean” did the trick ,  if not , then i’d advise the carbs to have a good blast from the air compressor everywhere inside it with carb cleaner from WYNNS too.  Or your local carb ultrasonic man can do this for you.

Can’t hurt to make sure the carb unit of the bike is totally checked over, cleaned and out of the way.

Then if the bike still misbehaves, we can dive in to other areas since carb is fully rulled out.

Also try what the guy above me has suggested too ^  .

[Author]

Posts