5 replies to this topic

[Old Bones]

I have fitted a Keihin 22mm ( similar to Honda TL 125) Carb to my Cub and it runs a lot better than with the new Amal I previously had on it, , The only thing is that it starts to blow a tiny bit of black smoke as you take it slowly off tickover but then clears, so Im guessing that it will need a smaller slow/idle jet.
This has proved to be impossible to obtain as its 28mm long and all thats available are 32mm long.
My question is:
Could I buy a 32mm slow jet and cut it down?.
Or
Try fuse wire as suggested by Totalshell to Penton on page 6 of Pre 65. would the fuse wire go through the main body of the jet or through the holes at the top end and how do you fix them in the jet.
Penton says that 3 bits of fuse wire were used and it cured his problem but the hole in the jet is so small surely 3 would not fit . Any advise or suggestions from Totalshell ,Penton or anybody would be most welcome
OLD BONES

[axulsuv]

Not to keep blowing his horn but if I were in country like you ,I'd contact Chris Stevens at classictrial.co.uk and talk to him about a OKO ...
I believe he is working on a flatslide carb for the honda 4t's with a accelerator pump circuit that may be the hot ticket for a cub ! It couldn't hurt to ask ...
good luck ,
Glenn

[Old Bones]

Thanks for the contact regarding the OKO carb I'm not sure I want to spend out further on a third carb .
I still have the new amal with lots of jets and slides so I have tried to get it sorted but as nothing seemed to work I fitted the Keihin and straight away it was a different bike it was such a difference that I would like to run with the Keihin if poss.
Im hopeing that experimenting with something that made such a difference as the Keihin will be worth it and it wont be as frustrating as the Amal
Regards
OLD BONES

[totalshell]

the fuse wire runs thro the length of the jet cut it about 10mm longer then the jet and bend the last 5mm each end over the end so that it stays put. makes a real difference on mine..

[Old Bones]

Many thanks Totalshell
I'll try it on the weekend, as a starting point I'll try the 5 amp and see what happens
Regards

OLD BONES

[Old Bones]

Here is an update on the fuse wire mod to reduce the size of the slow jet.........

I tried it on the weekend but it didn't seem to work for me because the wire fell out , The wire was cut off inside at the top of the jet and because the jet is vertical the wire ended up in the float bowl.
I'm assuming that I have the right jet, the one to the left of centre looking in to the carb and accessed by unclipping the float bowl,it has a screw slot at the bottom and screws vertically, at the end of the jet is what looks like a nozzle with some very small holes in it . I put 5 amp fuse wire up the jet and bent it over both ends there wasn't any improvement to the bike so I opened up the floatbowl and found the wire had been cut off at the top of the jet nozzle.
As yet I haven't found the little piece of fuse wire that was cut off.
Am I doing something wrong ??
Any help or suggestions would be appreciated
OLD BONES