Runs great, won't idle and have to tickle carbs even when warm?
- Thread starter Rwaurit
- Start date
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Welcome to the world of vintage Triumphs. You will get it running properly. There are some very knowledgeable folks here.
Sounds like fuel starvation.
First (easiest stuff first), make sure the fuel cap is venting properly. The hole in the fuel cap may be clogged. To check this, loosen or remove the cap and see if it'll idle.
Second, with a cold engine (to prevent possible fire), remove the fuel lines from the carbs one carb at a time. Have something to catch the fuel handy. Then open the fuel shut off petcock and see if the fuel flows to each carb freely.
Third, remove the carbs, open & dismantle them and clean them thoroughly. Pay special attention to spraying (can of carb cleaner) and flushing out the jets (primarily the idle/pilot jet).
First (easiest stuff first), make sure the fuel cap is venting properly. The hole in the fuel cap may be clogged. To check this, loosen or remove the cap and see if it'll idle.
Second, with a cold engine (to prevent possible fire), remove the fuel lines from the carbs one carb at a time. Have something to catch the fuel handy. Then open the fuel shut off petcock and see if the fuel flows to each carb freely.
Third, remove the carbs, open & dismantle them and clean them thoroughly. Pay special attention to spraying (can of carb cleaner) and flushing out the jets (primarily the idle/pilot jet).
Amal pilot jets are also famous for becoming blocked. Unfortunately they are not removable on the later models, they are pressed in and the orifice is very small. If you remove the fuel screw (on the cylinder side of carb) and shine a light into the hole you will see the small brass "plug" with a tiny pin hole in it. You will need a very fine wire to push through the tiny hole to clear it. I use a very small number drill, but am told a fine guitar string will also work.
Let us know how it turns out and what is causing the problem.
This may help.
http://www.scribd.com/doc/62278492/Amal-Concentric-Carburetor-600-900-Carb-Tuning-Manual
Not the best page I've seen but still worthwhile.
http://www.scribd.com/doc/62278492/Amal-Concentric-Carburetor-600-900-Carb-Tuning-Manual
Not the best page I've seen but still worthwhile.
The carbs are very easy to remove on a T 140......
Just loosen the hose clamp on the rubber hose connecting the carb to the cylinder head (and the air filter side), then unscrew the top of the carb where the throttle cable attaches and withdraw the slider (carefully).
Success! Removed the pilot jet screw, used a thread from a wire brush to clear passage. Adjusted the throttle stop screw as described in the attachment from Otherwise and fired up. Adjusted the idle and good to go. Tomorrow I'll adjust each carb separate by dropping one plug wire at a time. Thanks again everyone!
Rick
Rick
Congratulations, Rick; nice work. It feels really good doesn't it. Thanks for letting us know. 
awesome!
A standard set of guitar strings has a .016" string, second one down from the smallest (highest pitch). A light weight set of strings drops them all by .002". I know this because I was trying to rob a string yesterday from a set of strings my son had and it was a light weight set and had the .014 vs. the .016.
Triumph Tom
Well-Known Member
OK very simple answer here, You have AMAL carbs Im assuming you have the mk IIs. but when you say ticklers you throw me. You aught to have MkIIs but sounds like you have the concentrics ??? regardless the older they get the "pistons wear out" ARE your carbs hot after riding? the shoouldnt be. The AMAL carb is a ver simple thing. Are you running the right plugs? I suggest NGK, as there are immitation champions and their Q C has gone down. regardless. loose pistons,are bad but. You need to understand these are kinda like a brick w/ some holes drilled in the side. Is the tickler feel OK? you should hold the ticklers till a little fuel spills out the to there. If You take apart a toilet and understand how IT works, you can understand the way these carbs work. NO CV boot or BS. And I hate to give japanese cos any more business but a set of mikunis may be the way to go. If your pistons are worn out. If you have ANY slop they are and they oly go together one way SO. w/ Throttle cable still attached you can take the top of the carb off. Probably 2 screws on the elder or the carb I think you have is the carb mikuni copied and you can screw the top off. Ther is a needle w/ settings (if you have ticklers) and you can adjust the height. Are you idling too high? too low? I think A T 140 750 has the carbs I have pictured . those have NO ticklers I have ever seen (I have yet to see evrything). Let me know what carbs you have and we can work from there but for what it will end up to rebuild amals that dont belong, get the right ones or the Mikuni copys. no sense spinning your wheels.
Tom
Triumph Tom
Well-Known Member
Im sorry 1 screw and a spring loaded piece atop on the late 60s to mid 70s machines. The carbs that belong on a T 140 V are like the pic I sent. That carb was copied and The mikuni copys available ANYWHERE. Non purists love em! I put em on xs 650 yamahas. as I wrefuse to be part of a Triumph chop anymore. I think they are most beautiful stock. Ticlers..... shoud not have ticklers? should have a choke. PLEASE send me some up close high def pics. VERY interested.
Tom
Tom
Triumph Tom
Well-Known Member
Agreed possibly the best info.. Also rust in tank = BAD! After you have done the above, I suggest replacing the spark plug/ coil High tension leads. Or at least run her in the dark w/ no light and look for spark that should not be present. It could be shorting? Lastly, The way I have always set up my bikes or any twin is to set the idle high on L and R carb and remove (Use something non conductive, there are even special plastic pliers made for this) pull one tension lead , as she's running on 1 cylinder, ever so slightly bring the idle down to where she dies and just a tad more, NOW start up, repeat on other side. Remember how to sherpen a knife? well provided both cylinders are w/ in a lb or 2 of each other (compression tester required) You may be ok. Mess around w/ the p;ugs if you like. I have a surplus of the old school champions, but some swear by NGK. Personally I dislike the idea of jap parts but if it means reliability thats fine. ALSO if all else fails, Triumph made different length cams. If you have not yet converted to an electronic ignition system (Boyer I hear is good), It is not improbable that someone purchased a set of points and Triumph (depending what was on the stock shelf at the time, may have put a shorter cam in. This is fine at 1st but eventually causes the points to contact crooked, once they wear. If Nothing else, idle can be controlled by advancing or retarding the ignition. Do not go this route alone if you havent been backfiring or "breaking up" as It is most likely fine if you are getting good highway response and she starts 1st, 2nd kick. Also Clean your air intake box. I'm sure someone her can give better advice as far as points gap, hotter colder plugs, etc. But as a general rule you do to one side what you do to the other. I did own a sled that we bored one side and not the other (Arctic Cat 2 stroke lol but that's different).... Please keep me posted!
