Mixture screw out 3 1/2 turns?

Recently put a recon MK1 T5 engine in a Sprint frame, it’s all running perfect, great through the gears and a 70mph top end with a Simonini. The problem is the mixture screw on the carb has to be out 3 1/2 turns, as opposed to the usual 1 1/2, for it to run without spittin and coughin.
As i say it runs perfect on long journeys, can seem a little rich round town but nothing major. I’ve a 112 main jet in and standard pilot.
It’s niggling me something rotten.

Any ideas would be appreciated as I’ve run out of em.

Cheers, Hally

Hi hally , are you turning your screw out that far because its running weak and irregular at low revs ? If so it could be your crank seals leaking , whip your flywheel off and check for any oil leaking out around the seal , also check your gear oil level , if its low your clutch side seal could be leaking . Good luck.

Nah, it’s not that, i put a brand spank carb on. Cheers though.
She’s running great, starts first kick etc… You know what these things are like, they have a habit of coming to a head on the motorway in the piss pouring rain, usually in an area with no mobile signal.

Nah, it’s not that, i put a brand spank carb on. Cheers though.
She’s running great, starts first kick etc… You know what these things are like, they have a habit of coming to a head on the motorway in the piss pouring rain, usually in an area with no mobile signal.

Hi hally
3 1/2 turns does seem a lot. are you sure the mixture screw is from a T5 carb? I put a T5 screw in my Px200 carb and it would not tick over at all nevermind run.[:dance3:]

[:@] arse… I think thats whats going on with my motor… I’ve been messing around with different pilot jets and the mixture screw, and it always just seems to choke up around town, but is fine when on a run…

Cheers didge, just had a butchers and lo and behold the gear oils at a low level, just under 2/3 full after 700/800 miles. Looks like thats my weekend up the spout. I think there’s a lesson to be learnt here, don’t buy a recon engine off someone unless yer 100% (and this one came from a dealer).

Thanks again, H.

Nah, it’s not that, i put a brand spank carb on. Cheers though.
She’s running great, starts first kick etc… You know what these things are like, they have a habit of coming to a head on the motorway in the piss pouring rain, usually in an area with no mobile signal.

If you think your seal has gone , one easy way to check your clutch side seal has gone is by topping your gear oil level up to the top and give it a blast . If you get a large plume of white/blue smoke out your exhaust then its gone !
Unfortunately i know because i went through a batch of dodgy seals and had the misfortune of replacing them.