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Choke altarnatives?
Posted: Wed May 07, 2025 6:00 pm
by untertaber
Seems like my 660 starts very rough because the choke doesnt seem to do a thing, doesn't raise the revs at all. I think its because the plunger just gets stuck... I made sure to grease it in and all, but im wondering if theres a better altarnative out there.
Re: Choke altarnatives?
Posted: Thu May 08, 2025 7:09 pm
by donnybach
With the top of the carb off, you should be able to see if the plunger is closing all the way, and opening.
I’d take the float bowl off then, to check the choke passageway is actually clear with some cleaner spray. I had one which was totally blocked so had to drill it out.
Re: Choke altarnatives?
Posted: Fri May 09, 2025 3:57 pm
by untertaber
I cleaned the passageway should be good, il check if it works, was just wondering if theres a way to ditch the whole cable bit with just a pulley on the carb itself.
Re: Choke altarnatives?
Posted: Fri May 09, 2025 6:32 pm
by donnybach
People have put the direct “knob” version in successfully. Just make sure it doesn’t have the “finger” on the end if yours doesn’t.
I’d definitely take the bowl off though and see if the passageway is clear. Might be able to do it in situ. I usually replace all screws with hex Allen screws for ease of access when I get a chance. Four screws, replace the seal each time, or clean it and let it get back to size before fitting. I keep spare float bowl seals ready for refitting, they distort with petrol when in use.
Re: Choke altarnatives?
Posted: Sat May 10, 2025 10:38 am
by untertaber
Hm il finish up on reassambling the rear suspension today, might take a look at that afterwards. Hopefully I can leave the carb in place because getting it in and out is such a pain lol, im pretty sure mind has the finger/pin at the end. Do you have sny idea which part number people have used?
Re: Choke altarnatives?
Posted: Sat May 10, 2025 1:47 pm
by donnybach
The choke can definitely be easily changed with the carb fitted. Can’t help with the part number though sorry. Someone should chip in.
Re: Choke altarnatives?
Posted: Sat May 10, 2025 2:02 pm
by donnybach
Speaking of the finger, is yours definitely supposed to have it? This was the last thing I had to buy for mine. She was all over the place. The plunger wasn’t closing because of it being prevented by the finger/pin on the end. So the carb had been set up to run with the choke never fully closing. A new genuine choke plunger (&60) went in and it was sorted. I had to then tune the carb again obviously, back to near standard (excepting the arrow exhaust etc). Remove the choke (12mm I think) on the side of the carb. Simply unscrew and pull out. Remove the cable, measure the depth of the hole and see if the plunger can be pushed all the way in.
Re: Choke altarnatives?
Posted: Sat May 10, 2025 2:16 pm
by donnybach
Ok I’ve found my spare carb and old pin type choke. The cylinder is 35mm deep to the hole/jet. With the choke plunger in, I measured 3.4mm depth to the end. I removed the pin on the end (roughly just to see)and the plunger now went all the way, to a depth of 8mm, so the pin was holding the choke open about 5mm. The pics are in an earlier thread somewhere but I can’t upload anymore.
Hope some of this helps.
Re: Choke altarnatives?
Posted: Sun May 11, 2025 4:14 pm
by dzl
are you sure your choke/ starter tube O ring is in good condition and/ or not missing? if is in bad shape fuel will not be drawn out of the fuel bowl and into starter fuel circuit. It seals around the starter fuel tube that goes into fuel bowl. See part 17 here
https://www.firstclassmotorcycles.com.a ... or#content