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GT250A Pilot Jet increase

Posted: Wed Aug 19, 2020 4:11 pm
by daxman
Hi All My 'A' is a bit sluggish on the uptake - need to give it a slightly embarrassing handful and a bit of clucth slip to get going. Any thoughts about upping the pilot jet from 30 to 35 (or 32.5). Other than that I'm really enjoying it, even if it does hang on to the revs a bit on overrun.

Cheers all

Re: GT250A Pilot Jet increase

Posted: Thu Aug 20, 2020 12:46 am
by Alan H
Send your carbs to bluesmokeBaz for cleaning/refurb. He's done several sets for me on 750/550s and very pleased with the results. Literally fit and ride.
Saw him yesterday and he has several sets of 750 carbs ready for sending out.

baz99w@netscape.net for details/prices etc. and he's based in Dudley near Brum.

Re: GT250A Pilot Jet increase

Posted: Tue Aug 25, 2020 5:40 am
by daxman
Thanks. Not sure the issue warrants spending refurb money on. Plenty of other issues ahead of that!

Re: GT250A Pilot Jet increase

Posted: Tue Aug 25, 2020 6:22 am
by Alan H
Doubtless so, but you'll probably end up doing it anyway - and all the other stuff too. Just don't get disheartened.

Re: GT250A Pilot Jet increase

Posted: Sat Aug 29, 2020 6:29 am
by titan performance
Maybe have a play with the mixture screws first, richen them up a little, a quarter turn at a time and see if you get any improvement. If that don't fix it, then bigger pilots is the way forward. The pilot circuit is running lean, as that hanging on to revs on a closed throttle is a typical symptom. Make sure all joints are sealed properly as air leaks between cylinder and airbox can cause these issues. Check for cracks in the inlet rubbers too. Are you running the OEM airbox and filter?

Re: GT250A Pilot Jet increase

Posted: Sun Aug 30, 2020 3:57 am
by daxman
Thanks for the tips, Plug colour is good, but I think head gasket has been leaking slightly. 14 ft.lbs on these seems pretty low
Airbox is standard btw using standard filter frame with some home made sponge from ebay - sold as air filter sponge.