• Topics: 38
  • Replies: 545
Nov 30, 2017
North UK

Usually the bog downs or cutting away means  electrical issue or fuel delivery system.

Lets deal with fuel first.

  • Go to the rear pump.  Open its metal shield cover.  You will see a glass window inside.  Get CARB CLEANER.   Spray inside through the GOLD PORTS only.  Do not spray inside the GREY port.    Now you must see the particles get cleaned out.   remove the window  (watch the gasket!). Clean the window too.  Dont remove any moving parts of pump.  Clean up and close the pump tight. Fit it back on the bike.
  • Change the fuel filter.
  • Clean the carbs….  see below

Get compressed air. Open the carb. Clean HARD the Pilot Jets. MAIN jets. And also the *enrichment tube* that is permanent on the carb.

Then clean every *hole* you see inside the carb hard so all the particles go out. It is crucial.   CARB CLEANER (Liquid) helps also but it is better to use compressed air to blast every tiny hole though!

Put your carb upside down on a table (floats facing the sky).   Get a ruler.  Start from 0mm on the FLAT EDGE of the carb base (where bowl gasket sits on) .  then make sure all 4 floats are 7mm height.   not less. not more.   this float controls how much fuel you get from idle to top gear. You dont want the carb starving or overfueling. 7mm precisely at the top of the float on your ruler.   or adjust the float metal tangs a little bit! Then recheck.

Floats all good?.  last mission is to clean the diaphragms at the top (black slides) and search *Slide Mod* on this forum on how to improve the slide needles.

Now the carb should be really clean and prepared.     before fitting on the bike…. do the following below…

Go to intake manifolds.

  • Be very gentle. It is very very very hard to get new ones (not made anymore).
  • Remove intake manifolds
  • Check for cracks / damage (vacuum leak!)
  • Check Oring isnt cracked (very important for air leaks too)
  • Clean them. And grease the ORings.
  • Fit them back on the back.
  • Use fresh bolts and washer and tighten (be gentle!)

We have cleaned the carb.  we have checked the intake manifolds.    put the carbs back.  put the airbox back too. Be gentle as carb intake manifolds will crack open if there is too much weight or pressure on them.

Connect the fuel pump.  get fresh fuel lines.    get fresh vacuum lines and clamp all lines tight to stop vacuum leaks.


Start your bike. Get CARB CLEANER.  spray the intake manifolds while she is on IDLE.   if revs go up^ = you still have a leak.   fix that area.    if you spray rear manifold and revs go up , investigate rear intake system there as an example.

Last mission  go to the TANK.

  • If you have a vacuum tap on the tank.   start your bike.  rev up multiple times. You should see fuel gushing down the filter. That means the tap is squirting fuel in to the filter.
  • After a short ride, fuel filter should be FULL if it is a small one.
  • If you have a manual ON/OFF tap on the left side of your bike frame ==> Go under the tap. Open it. Clean the dirt traps inside.
  • If you have a ON/OFF tap that also means your tank has 2 pipes that go down to the ON/OFF tap.    On your tank => remove the spigots that side inside the 2 holes. ((From tank rust or dirt that may prevent fuel coming out of the tank to feed your bike))



I hope i have made sense. Try everything i said above. And let us know if there is improvement even if it is small or better. It will respond better when you make progress.

// Meditation doesn't mean you have to sit still....

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