Gsxr 1216 Mukini 36mm carb problem

[jimbob1975]

Hi All,I have put fresh petrol in the bike as its  been stood for a while and started it up.It was running fairly crap so whipped carbs off and cleaned float bowls and jets and back together.It starts up and only runs on 2 cylinders.The two middle cylinders.When I open the throttle it gets to about 4 thousand revs and runs on 4 lovely then when revs drop back down onto 2 pots.I know jets are clean could I have altered the float heights and are they adjustable or fixed?Had all plugs out to check sparking and all perfect??Cheers

[Nick]

Crap in pilot jets? Float heights are adjustable by carefully bending the metal tang on the float retainers and are normally around 14 - 15mm.

[Fula28]

Try a tin of profi fuel max additive in your fuel works a treat saves loads of time only needs a little as per instructions. Honest best stuff out there. 

[Fula28]

[jimbob1975]

Hi All Thanks for the replies I will check it out tomorrow and post back with the outcome.

[nightrider]

If it was running fine when you put the bike away and now it has a problem don't change your settings.

Clean your prime circuits again.

Pull out your prime jets and clean them with Carb or Brake cleaner in a can then blast them with compressed air.

Take note of your current prime screw setting by turning them in and counting the 1/4 turns (each carb might be slightly different) then turn them out to 4 or so turns.

Spray the prime circuit with Carb or Brake Clean and then carefully blast out with compressed air.

Look down venturi (with eye protection) and see if cleaner spray is even or spraying at all. If not, repeat process.

 

 

Edited August 14, 2016 by nightrider

[jimbob1975]

Hi,Update on the bike.Have put in a set of new plugs and it has fired up on all four cylinders.Except now it wont tick over and is reving its nuts off as if its on choke.It settles down after 30 seconds or so but as soon as you blip the throttle revs hang and wont come back down!!Throttle cable is set perfect and is returning to the throttle stop ok.I have left all the settings alone as it was running perfect before.If the float bowls aren't sealed very well on the o rings could fuel be filling up the bowls and acting like on choke??

Edited August 15, 2016 by jimbob1975

[Gixer1460]

Usual symptom of an intake air leak and / or a slightly frayed cable inner - either way, excess air!

[colinworth79]

once had this where one of the diaphragm rubbers had got folded over when the plastic top was put back on .

[jacktar01]

Spray wd40 over inlet side and rubbers if revs die down you got an air leak