Triumph Rat Motorcycle Forums banner

41 - 43 of 43 Posts

Registered
Joined
2,008 Posts
Coachconner - I think you misunderstood my mixture settings I quoted. They are only 1/4 turn difference between them. I was quoting the range which seems best on each side.

Yesterday I tried more combinations of mixture settings and choke as well as trying a new coil (just to eliminate it from the list), and it made no difference. So old one back in.
Also installed new air filter (K & N high flow verses the Uni-filter high flow old one) and that made no difference either. I have left the new filter in place.
I tried increasing the idle, but that made no difference.

End result was that with the mixture screws at 3 1/4 and 3 with full choke or 1/2 choke it starts, runs and keeps running and the engine "sounds stronger" with this setting.
No black smoke; only steam and invisible gases!
Starting technique seems to be once it fires and starts to run, I open the throttle just a little to make sure it keeps running, and slowly reduce the choke to maybe 1/4 and it will idle at 900rpm whilst warming up.

I warmed the engine right up and re-balanced the carbs, which weren't very far out and also adjusted the idle.
I then rode the bike around in a small circle outside the garage and it pulled very strongly from standstill with no hesitation. Still no black smoke.
Ok that makes sense It sounds as though you hit the sweet spot that your bike likes. Ride and enjoy. I'm glad you reached a conclusion.The more tank fulls you run through it the better it is likely to get. Cheers.馃嵒
 

Registered
Joined
22 Posts
Discussion Starter #42
My bike has always been hard to start in cold weather. The two things that I have had success with are pulling the side cover and covering the snorkel with a rag so that it acts like a choke, a real pain. The other is with the enriching knob pulled out turn the idle DOWN. What this does is close the butterfly, which is now restricting air and acting like a choke. Once the engine runs for about 30 seconds I turn the idle back up. I usually turn it down 3 good twists.
Mike
Thanks for the info' Mike. I'll bear it in mind.

Cheers.
 

Registered
Joined
22 Posts
Discussion Starter #43
Thanks for the info' Mike. I'll bear it in mind.

Cheers.
Yet more testing results! -

Just as an experiment I removed both shims and reset the mixture screws to (left) 2 1/4 and (right) 2 and with full choke and no throttle it tried to run but cuts out quickly.
With 1/2 choke it was the same.
Adjusted screws to 2 1/2 and 2 1/4 - With full choke tried to run but cuts out, although it sounded "stronger".
With 1/2 choke same result and cuts out too quickly to keep it running on the throttle.
Carried on adjusting screws at a 1/4 turn each time and trying with full and 1/2 choke until I got to (left) 3 1/4 and (right) 3 turns out where with full choke it tried to run but cut out and with 1/2 choke it tried to run and I kept it running with a little throttle but just cuts out.

Replaced both shims;-
With screws at (left) 3 1/4 and (right) 3, and with 1/2 choke and no throttle it ran much longer so I could catch it on the throttle and kept it running. Slowly reduced choke to a minimum and after about 1 minute it would try to idle very slowly at about 600 rpm.
I warmed it up and then idles properly at about 1100 rpm.

I think I'll leave it at that and see how it goes.
Thanks very much to everybody who has given me advice and information. It has all been very useful.
Ride safe!

Baron Pete.
 
41 - 43 of 43 Posts
Top