Mk1 Jetting?
Mk1 Jetting?
Hi
I have recently bought a Mk1 & wondering if anyone has any recomendations on jet sizes.
The bike (i believe) is standard apart from a 'Mugen' tail pipe & some reeds, not sure on make of reeds, but they have a blue strip of plastic that fits between the reed & reed stop.
The bike runs fine on medium to top revs, it also starts well - two soft kicks then one or two hard kicks when cold & first or second kick when warm (no throttle).
The main problem is the tick over, it either ticks over very low & sometimes stalls or if I wind in the tick over screw in about 1/8 turn it seems to tick over quite high & causes the engine to hunt, If you then engage a gear & let the clutch start to bite, the revs do come down & stay down.
I have removed the carb & cleaned it (unfortunately I can not remember the jet sizes) but this did not seem to make much difference. I have also tried adjusting the air screw but also not much change.
I am wondering if just putting some new std jets in would possibly help or if I should adjust slightly to suit the Mugen tail pipe?
Look forward to receiving some help with this.
Regards
David
I have recently bought a Mk1 & wondering if anyone has any recomendations on jet sizes.
The bike (i believe) is standard apart from a 'Mugen' tail pipe & some reeds, not sure on make of reeds, but they have a blue strip of plastic that fits between the reed & reed stop.
The bike runs fine on medium to top revs, it also starts well - two soft kicks then one or two hard kicks when cold & first or second kick when warm (no throttle).
The main problem is the tick over, it either ticks over very low & sometimes stalls or if I wind in the tick over screw in about 1/8 turn it seems to tick over quite high & causes the engine to hunt, If you then engage a gear & let the clutch start to bite, the revs do come down & stay down.
I have removed the carb & cleaned it (unfortunately I can not remember the jet sizes) but this did not seem to make much difference. I have also tried adjusting the air screw but also not much change.
I am wondering if just putting some new std jets in would possibly help or if I should adjust slightly to suit the Mugen tail pipe?
Look forward to receiving some help with this.
Regards
David
Sorry david, cant help too much with jetting but that does sound more like an air leak. Either on the intake round the reed block, or worst case one of the crank seals is on its way out.
To check if its a crank seal, remove the gene cover and get a mate to hold the bike, grab the flywheel and check for any up and down movement. this will show up a worn main bearing and if so then the crank seals are shot. The other crank seal if gone would drink gearbox and should be quite noticable. failing that strip the carb and replace the pilot jet, leave the carb in coca cola for 24 hours before cleaning and blowing out with carb cleaner.
To check if its a crank seal, remove the gene cover and get a mate to hold the bike, grab the flywheel and check for any up and down movement. this will show up a worn main bearing and if so then the crank seals are shot. The other crank seal if gone would drink gearbox and should be quite noticable. failing that strip the carb and replace the pilot jet, leave the carb in coca cola for 24 hours before cleaning and blowing out with carb cleaner.
Thanks Admin
I have ordered a new set of jets from LeisureTrail in the hope that the jets are just slightly blocked.
I once bought a Kawasaki ZXR400 which had been sat for a few years, it ran like an absolute pile of shite when I got it going, I had it dynojetted, It was tested before jetting with about 45BHP, it came out with about 65BHP, purely from changing the jets!!
I have ordered a new set of jets from LeisureTrail in the hope that the jets are just slightly blocked.
I once bought a Kawasaki ZXR400 which had been sat for a few years, it ran like an absolute pile of shite when I got it going, I had it dynojetted, It was tested before jetting with about 45BHP, it came out with about 65BHP, purely from changing the jets!!