[Bonnyjo]

Starting from cold my T140 Bonneville Special with Mk2 Amals starts easily on the choke but I have to let it idle for maybe 10 minutes (with choke off) before I touch the throttle. If I crack the throttle in that first 10 minutes it stalls. It does not seem to have any fast idle.

I have to let it idle with the choke off as if I leave the choke on it stalls anyway. I live in Australia so I am not talking about really cold conditions.

No problems once it has warmed up. Bike has <400 miles on it from new.

Anyway, it is such a pig I do not want to ride it. My 69 Tiger runs like a champion, no starting issues at all.

Does anyone have any ideas?

 

[sandergecko]

That's a carb issue.
I don't think the choke is needed in Oz.
Check your shop manual how to adjust the carbs, if that does not work your jetting might be wrong.

What main jets doe you have? what position is you needle in? Are your carbs clean? Are the pilot jets clean?

Up to 1/8 throttle is controled bij the pilot jet, 1/8 to 1/4 by the throttle valve cutaway, 1/4 to 3/4 by the needle position and 3/4 to full by the main jet.

Do an intro in the new members section and get more free help....

 

[YETI CUSTOMS]

I set up mikunis on harleys and all the owners say"how come it doesn't idle when I push the choke in after starting it" well its because it hasn't warmed up yet mk2 amals are very similar if it runs fine warm leave it alone

 

[Tony the torch]

Mark II's are one of the harder carbs to get set right, (yes, they are a lot like Mikuni's).
but properly set up they should only need the "enricheners" (it replaced the ticklers, it's not a choke) to start. Properly jetted it should idle and run and rev up right after starting.
If you have the T140 "E" carbs they were set up as DOT emissions approved carbs and require some re-jetting and new slides. there are kits available to do this and there was several Triumph service bulletins about those carbs. But, going by memory you will need a new 106 needle jet and needle (the correct one is 1/4" longer) and a new #35 pilot jet and a new #25 enrichener jet, and then the new 3.5 slide to make them run right. and you may still have old dried up and leaking enrichener seals. And then after that work all that you'll still have blue exhaust pipes.
IMO, the Mark II's can be a nightmare carburetor, and it would be a lot easier, faster and cheaper to put a brand new pair of flat slide Mikuni's all set up from Sudco on it and be done with it.
If you go to the BritBike forum there is a 200 page discussion on Mark II carb problems.
as for me, I love Amal carbs, just not the Mark II's...

 

[Bonnyjo]

Thanks for the tips gents, you have given me somethings to check. I will let you know how I go.

 

[srook]

Instead of cracking the throttle try rolling it on. A T140D should have just as much low end power as your TR6. The MKII carbs are good carbs and once set-up they will give you a really nice running bike.

Try this: get the bike really warmed up and set the idle at 1100-1200. Thats a little fast but it will give you a better idle when cold and its not like you're sitting at a stoplight with the thing reving at 2500. Sync your carbs before you set the idle. You may actually have the updated jetting that Tony mentioned as the leaner jetting was only for the American market.
Scott

 

[Drew71]

No problems once it has warmed up. Bike has <400 miles on it from new.

Does anyone have any ideas?

There's your problem right there, Its not run in yet. I better take it for a run for you

Cheers

Drew