Mikuni Question

[OverTheHill]

Sorry, not sure what i was thinking--i'm thinking 250 husky 'dunno why' but now see H1 H2 is that a 750 Kwaka sidecar--no doubt piston port anyway--carry on & ignore my woffling.

[Wasp]

Yes , we synchronized them from bottom up and checked with the mirror to make sure of that . Yes I have spoken to Ian  and showed him the carbs . They are made by Mikuni , but for Kawasaki  triples only . Slides are different and the shape of the jets are different to the normal Mikuni parts . Of course being from 1974 most Kawa  part numbers are obsolete now . With all your blokes input in mind  I will redo them again , maybe I have over looked something very little . I will give it one more go , otherwise  Ian recommended to go for the new half round carbies and then there would be plenty parts to play with . Thats the fun with those old girls , they are a constant challenge , but soo much fun to ride when they are on song .  Some blokes in UK have welded reed valves onto  them for better down low delivery , but some how I feel it defeats the purpose of going for that type of bike .

[sleepy]

Can you give some details on the motor. Is it stock with stock pipes for road use or modified?

[matcho mick]

"normal mikunis",shit most of my bikes run R jets,(ok so they're all early 70's,so thats the norm),my museum pos yamaha YDS R thingy was having b/e issues too lean,banged 60 pilots in (35's),changed the P-0,s for P-4 (availble Hatricks),dropped needles back down,bingo,can now start easier, bonus , motor to start line at a reasonable low rev,actually working on a H1 atm,(500, overthe hill  )sort ignition,then back to  carbie issues,(think they're related),

[Wasp]

Engine is standard , fresh pistons and rings .New  Higgs pipes , new Lakeland ignition and timed to the book . The bike is 750 H2 1974 (C)

[Lozza]

Lozza , wouldn't lifting the needle more , exaggerate the problem more ?The first 1-5 mm of slide lift , that is where it is too rich , after that it all comes good .

So it's at the full rich or position 5? If it is in the initial part of throttle opening your looking at the parallel part of the needle before it tapers. Look at the mikuni needle chart and look for a needle with the same taper dimensions but with slightly fatter end to the needle. Changing the atomiser will only shift the whole fuel curve to the left or right. Mikuni needles are not really designed to run on positions 1 and 5 that means new atomiser. Something you could try is to calculate the annulus area between various needle/ atomiser combinations to find a slightly smaller area, rather than spend a fortune on tubes and needles. I would have said stick 3 PHBE's on there I can tune them from a description 

[80-85 husky]

on your recheck, make sure the needles are seated in the top of the slides and pinned by the spring / clip whatever is there. "floating" needles can cause weird shit to happen in the carb and rich early can be one of the symptoms

[matcho mick]

geezas Lozza,spending a small fortune on needle/emulsifying jets aint gunna cost 3 new effing delortos,i'm thinking N series next ones back x 3 isn't as exccy??,hmmm funny "my" 500 has new chambers from pommyland which richened the motor up too??,

[sleepy]

Engine is standard , fresh pistons and rings .New  Higgs pipes , new Lakeland ignition and timed to the book . The bike is 750 H2 1974 (C)

So did it run ok with the stock pipes? My money is still on the slide cutaway if it is rich just as the throttle is opened above idle.

[Wasp]

I bought is mint from Canada via a agent displaying lovely pics ...... To cut a long story short , ignition , barrel , pistons, clutch  and exhaust are new now and it is running at last,now that we fixed all that ... If I can can get that last bug out of it , I will finally have my dream bike that I wanted since a teenager.

[Lozza]

geezas Lozza,spending a small fortune on needle/emulsifying jets aint gunna cost 3 new effing delortos,i'm thinking N series next ones back x 3 isn't as exccy??,hmmm funny "my" 500 has new chambers from pommyland which richened the motor up too??,

I never suggested buying new Dellorto's.

[Wasp]

I love the Dellortos for the chrome trolleys . They work well there because of of the pumps and many jetting options .  But this is a challenge I like to ride out on OEM Mikunis if I can . There will be a way . There must be a way .

[shelpi]

May I suggest you purchase the Sudco 5th edition mikuni tuning manual and use monometers and or vacume gauges for synchro of the carbs