Hitchcocks Forum

Does the choke on these carbs do anything whatsoever?

Maybe it depends on the bike. On my Mk1A Interceptor on cold days you need it to start and then about half to run until good and warm. Even on Wednesday afternoon when temperatures were in the low teens it wanted choke for about 15 minutes.

REgards, Mark

Yes, on a 350 bullet they can flood your engine into unstartability in only 2-3 kicks and waste hours of your life routing/unsticking the cable. They are also quite good for having the lever slowly loosen and slip back down when on long runs leading to a gradual loss of power and terminal plug sooting.

On my 1A it needs full choke and plenty of tickle when cold. When hot it still needs choke and occasionally tickle - possibly due to fuel evaporation. I don't think I have ever flooded it since sorting out the ignition.

On my bike slow starting always seem to be down to not enough choke. Make sure that the choke cables are adjusted correctly. When I used the plastic type 2 into one cable connection I resorted to using bath plugs before I found that if the cable was adjusted so that the choke came off fully it was not going down sufficiently to fully choke the carb. I bought a stainless steel 2 into one and it now operates correctly over the full range

My experience on my 350 is the same as Stinkwheel's It won't start from cold with the choke. It starts first kick after you tickle it and don't use the choke.

Valsp, that's interesting, I found the same thing with the choke splitter box on my Mk1 (the 1A is fitted with it's original cables and box,) but I forgot until I read that! I've recently fitted Premier Concentrics to the 1A and doing that has changed the starting routine slightly, I suspect because the Premiers have the pilot jets in a different location than the old Mk1 conc. I'm going to experiment with the new range of pilot jets at some point as well to see if I can fix the stalling just off idle problem!

REgards, Mark

John R - "Does it do anything whatsoever? "

Of course not - it's simply an ornament.
)
As much use as a one-legged man in an ass-kicking contest....just ask stinkwheel.

Sorry, couldn't resist.......

As ever, other opinions are available.

If you ever wanted to do away with the choke, it is possible to buy a chromed brass slide with no provision for a choke.



I've gone right off Amals of late. I'm currently looking into ways of fitting a VM28 mikcarb to my 350 bullet (tuned head). I've done drawings for an adapter plate, just need to find time to pop them into my local machine shop so he can tell me why it wont work.

I thought carby studs were same spacing as 500s. You can buy a jap mikuni rubber manifold for a 500 as 28mm is std carb on this, vrom memory I had to make longer studs for the inlet due to the thickness of the rubber flange, indian ones are crap rubber perishes quickly.
Gave a mate my 28mm micarb for his 350 he had trouble fitting it under tank but manifold fitted ok. Much easier with the tank off you might have to use a 500 throttle cable when I went from 28mm to 32mm std cable was to short and slide would not raise all the way.

Nah. The studs on a 350 are 2" (50.7mm) hole centres and the 500 are 60mm