Without giving a lesson on the search function, can someone tell me the correct position of the handlebar mounted choke lever on my newly acquired 1971 Triumph Bonneville (2600 original miles, 100% original)? Im assuming full tension on the cables raises the choke slides inside the carb slides? Or is the lever parallel with the handlebar in the slack position? It will run in both positions, but Im having a hell of a time getting a nice idle in either position. I cleaned the carbs and have clean fuel going to both, new battery, cleaned points and set them, and reset them. Found the advance mechanism was stuck and freed it up, works good now. Thanks [img:center][/img]
Not quite sure how the lever should point on your particular bike but tightening the cable pulls the choke slide up to run position. If it runs better with the choke down that could mean you are too lean. Did you make sure you got the pilot jet cleaned? Also, need to synch slides. Check float levels. Here's some good general info: http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html
I keep a supply of the #78 drill bits on hand. Seeing as you have more than one Brit bike you'll need a few. For a handle use some superglue to put one into the end of a plastic squirt tube off an old WD40 can or similar. I order mine here. http://www.micromark.com/no-78-drill-bits-pkg-of-6,6661.html
the correct position of the handlebar mounted choke lever Im assuming full tension on the cables raises the choke slides inside the carb slides?
The cable inner is 'round the lever pivot, so the lever position with most inner 'round the pivot has the chokes' positions at their highest? As the cable is parallel to the 'bars, this lever position will be at right-angles to the 'bars? Also, you could remove the air cleaner covers and stick a finger into each carb. to feel for the choke slide?
It's wise to look/stick a finger into each carb. anyway, to check that the choke slide is fully-withdrawn from the venturi - a stretched cable inner stops the slide being withdrawn completely.
Once you've established that the choke slides are fully out of the air-stream, you might want to screw the lever pivot down tight and never touch it again - the only one of my Triumphs that still has the chokes is my T150 ... and that's only because the choke lever mounting is part of the brake lever mounting. Apart from that, the chokes were nothing but a pita, no help starting or warming up the bike but vibrating on at times I couldn't reach the lever (I have a normal-length thumb, rather than the 6"-long one the AMAL choke lever designer had ...). When I built my T100, I didn't even fit the choke components.
Easier way to clean pilot circuit: get a .010~.015" steel guitar string (cheap at any guitar shop), remove air screw, push guitar string through until you feel it pass through the air jet at the other end. Then blow some air or brake cleaner through it from the air-screw side. Repeat.
Drilling the jet out a bit larger (as mentioned above) is the best fix, but working with those tiny drills can be a hassle.
If it won't idle (and if there is no significant change when the air screw is turned in and out) pilot circuit is plugged.
Last edited by Nick; 02/15/143:22 am.
When people who should have known better cautioned me about the dangers of motorcycle racing, I always told them that a fear of death is nothing more than a fear of life in disguise.
Pull the air filters off and look in the carbs while moving the lever. Chokes should rise and fall together. The "run" position is the chokes up all the the way. Most of the time you should only need the to tickle the carbs to start. My 72 has no chokes. My 68 has them and I never use them. I just think the lever looks cool.
Guitar strings are 10 to 14 dollars for 3 and they are not the correct size. # 78 drill bits are 8 bucks for 6 and they are the correct size. You are not drilling the jet larger you are cleaning it correctly.
1968 T120R 1972 T120RV Any advice given is without a warranty expressed or implied.
Thanks for the replies fellas. I will get some #78 drill bits coming. I have entered this bike in my first show ever (AMCA) and one of the requirements to enter is to start it and it has to run5 seconds. It will do that now, so that will get me in the door. I plan to ride this bike in the Spring so I will pull the carbs off after the show. Thanks again.
Looks like the way its mounted, rotating it clockwise against the stop will pull the chokes up. You need to pull the air cleaners to check the slide synch anyway so will give you a chance to verify. Like someone mentioned you probably don't need to use them except maybe when the temp is below about 50F or so. Just tickle'em good.
Thanks, it starts just fine tickling the carbs. Ive heard of people removing them, so I think I will do that when the carbs come back off.
Works well with most. I had a T150v with no chokes, would start even at 30 degrees without them. But, on a triple one can open the all throttles slightly with the screw on the manifold. When my A65 had Amals it gave trouble starting at low temps, would start but it wouldn't stay running. You will need to plug the choke cable holes in the tops of your carbs after removing the chokes. I guess you could just remove the choke slides and springs, leaving the cables where they are and silicone the ferules in place to satisfy the rivet counters.
If you want a completely predictable bike-buy Japanese. If you want a bike with character--buy a Brit bike. Some of my Brit bikes start fine with tickling and no choke. Others need choke for the first couple of miles otherwise they splutter and misfire in a way to make them virtually unrideable. Brit bikes are like women--what works with one doesn't work with another --and vice versa. IMHO--don't remove the chokes until you have used the bike for a good while--only then can you be sure that you don't need them--or find that you do. HTH
You will need to plug the choke cable holes in the tops of your carbs after removing the chokes. I guess you could just remove the choke slides and springs, leaving the cables where they are and silicone the ferules in place to satisfy the rivet counters.
AMAL can also supply the small screw with the correct thread to fit in place of the cable adjuster in the carb. top.