Questionhi john. i have a 1978 750 t140ve triumph. my problem is the float needles keep leaking gas. the carbs are mark 2 type amals. i replaced the needles, floats, gaskets, and cleaned up the seats. i adjusted the seats up and down to change the float level. still leaks! i was told my seats are bad. can,t find replacement seats. should i try a machine shop to tryto make new seats or have you a better idea? thank you for your time george
AnswerGeorge
I think you have an odd problem. I can understand one carb leaking, but if both are doing so, something has gone wierd. I am hoping that when you did the rebuild that the parts were of good quality from a reputable dealer and were the right pieces for your machine.
The principle of a float and how it operates is fairly simple, so if the parts match up, all should be well. It is not within my experience to have the needle seat to wear so badly that that they no longer seal, but I can accept that it is possible. They have might have accidentaly inflicted tool marks or nicks. Usually, its the needle itself that goes south, since it is made of softer material.
Since I have to cover all bases, my advice to you is to double check yourself and your assembly procedure to make sure there isn't a mistake there somewhere. Also, be sure that your ticklers are lubed and functioning freely. And if there is a little bit of varnish or rust floating around in your fuel tank, this stuff can settle in the wrong place and give you no end of grief.
There are newer needle designs available, other than the old hard white plastic, that may offer better sealing capability. Check with a couple of dealers and see what they have or can get.
The last resort would to be to machine new seats, which can be done, but might be expensive. Or you can just give up and replace the offending bowls if you can find them as separate pieces. I would hate to pay for a whole new carb if I could avoid it.
I know I have given you a lot to think about, but let's hope the solution is here somewhere.
John
