What's the correct pilot jet for a 1966 250 CSR?

[clanger9]

According to my factory manual, the 1963/64 model has a 25 pilot
According to the F Neill manual, the 1963/64 model has a 30 pilot
Neither manual makes any reference to the carburettor settings on the 1965/66 engine, even though it has a much higher (9.5:1) compression ratio.
The parts list says that a 389/82 carburettor is fitted to all these models, which implies that the jetting should be the same (but the Lightweight parts list isn't always 100% correct...)

I suspect that a 30 pilot might be correct: on my bike, the idle mixture screw is nearly all the way in on a 25 pilot (no air filter, open exhaust) which suggests it could do with a slightly bigger pilot jet...

Any late-model CSR owners out there? What pilot jet are you running?

[cbranni]

I aint got a CSR ..................but you should be running an 82 which has a 20 pilot No 3 slide 200 main .106 needle jet with needle in middle.
Just my thoughts
Colin

[John Donne]

For the 1966 Matchless G2CSR the parts book shows for the following for the Amal Monobloc.
043574 Carburetter 389/82
Throttle Valve size 3
Needle Jet 106
Pilot Jet 0.020
Main Jet 200
389-056 Jet Block 1-1/8

An extension venture 044029 was also fitted as standard

The above is also relevant for the 1965 G2CSR.

[clanger9]

Thanks for the info all!

I've settled on a 30 pilot for now, as it seemed lean on a 25. Plug colour seems more or less spot on.
My bike runs an open pipe, so that may explain the difference...

[Duplex]

Is there anybody out there with a 389 no 3 throttle slide thanks

[clanger9]

What condition? You can have my worn one.
New ones are £18.95 from Feked.