NC30 choke issue

[krismarmoy]

Hi, ive had a good search but cant find much for my problem.

Ive just rebuilt my carbs, usual story. Float heights set, 118F, 120 R, pilot screws 2 1/4, new gaskets, and balanced carbs with vacuum gauges.

Now, the bike wont start easily from cold with choke. Im getting full movement from the choke cable / arm on the carbs, the 3 choke plungers are free moving. When I try to start it (Full choke no throttle) , the choke doesn't do anything, it just fires afew times, after afew times of doing this it eventually fires up with a little throttle. Once running and warm the bike idles and rides lovely

Once its running, the choke has no effect on the rpm at at all. so I assume that even though the plungers are free moving, the choke isnt doing anything to richen the mixture or increase the idle speed ? (How does the choke increase idle speed out of interest ?)

I didn't have the choke mechanism apart at all, at it was working fine before i had them apart, it there anything i have missed or could of done ?

Any ideas ?
Thanks
Kris

[Cammo]

I didn't have the choke mechanism apart at all, at it was working fine before i had them apart, it there anything i have missed or could of done ?

Did you remove the choke cable from the carbs before removing them? If so, the cable might just need a minor amount of adjusting where it clamps to the carbs.

I usually take the slack out of the carb actuating arm (carb choke actuating arm pulled a little to the right but no plunger movement on carbs) then clamp this cable position to the carbs to set the 'closed' position'.

[krismarmoy]

thanks for the reply, ive got the cable adjusted correctly and ive taken the slack out of the arm. Is there anything internally within the carbs that can make the choke not respond despite the plungers working correctly ??

All ive done is ultrasonically clean the carbs

[TommyTheGun]

The choke is a fuel enrichment circuit. Opening it is meant to let more fuel out. If your plungers are moving but not making any difference it would suggest that the choke circuits could be blocked. Could try taking the plungers out and giving the passages good spray through with carb cleaner.

[Cammo]

All ive done is ultrasonically clean the carbs

Ah right, as Tommy says remove the plungers and give everything a good clean - use carb cleaner (or petrol) and compressed air. There's a chance the choke passages could be blocked.

[krismarmoy]

Much appreciated, will whip the carbs off again tmrw and give the enrichment circuit a good clean. Will report back !

[krismarmoy]

also, how does the choke mech increase the rpm when the lever is pulled ?? I cant see it operate the throttle quadrant at all ???

[bikemonkey]

It doesn't operate the throttle at all.

It just opens a passageway to dump more fuel into each cylinder making the mixture richer.