I am wondering if anyone can help me. I have bought 3TJ which did not tick over when I bought it. It had not been run for a couple of years. I have checked all the jets (they are all the correct size), drained the fuel and cleaned the carbs. The needle circlip was in the second groove from the top of the needles which I understand is wrong. I changed these to the the third groove from the top. The filter box has been drilled so I got another one from eBay.

The bike starts and ticks over without the air filter box but when the box ( without the filter) is put on the engine eventually cuts out. It won't rev cleanly with the air box on and with it on or off it stutters at around 5 to 6k revs. Some times I cant get the revs to rise at all withe the air box on.

One thing I could not check was the needle sizes as there were no visible markings.

Has anyone any idea where to start?

Sounds very much like it's been raced at some point, by someone with less than adequate modding knowledge

I think you need to get absolutely everything back to stock before you go any further.

You changed the fuel filter ? There's also a gauze filter in the carbs where the fuel hose joins.
It might be the air screws have been adjusted when the rest of it was done.
Check the float bowl gaskets too.

You could look for a second set of carbs, expect to pay aBout 50 for them.

where in't world are you?

I live in a place called Chalford Hill between Stroud and Cirencester.

Thanks for the advice guys, I suspect the needles are non standard. All jets are correct but I get the feeling that the needles have been buggered with. Am thinking seriously about buying a replacement set of carbs but will persist with the ones I have.

Lowered the needles today and got a tick over with the air box and filter in place but it revved like a dog and had no power to get of the line just stalled. Time to have a think.

Sorry missed this bit.
Yes changed fuel filter and did not know about gauze filter in carbs.
I have adjusted the screws.
I am convinced that it's getting too much fuel.

I remember Chalford ... back when I was a kid I lived in Badminton and hung out in Ciren and Stroud (and Tetbury and Malmsbury)

I live up near Chalford Hill School by the "donkey fields" I bet you went there as a kid.

So I sort of got the bike running but as soon as i let the clutch out it dies. I am still convinced, at the moment, that it is the needles and needle jets. As I say they have been messed with but as I can't identify what they are. I want to get a new/second hand set of the correct spec. Anyone got any advice on where I can get these from?

Thanks

If it's got the right jets but still getting too much fuel, float height too high?