MB BGM 225 closed throttle issues

[peter357bikes]

Just put together a MB BGM 225 kit with LTH reed valve, B race stealth exhaust and TMX 30 Carb. Accelerates pretty well and when on the move it fairly flies along. However on closing the throttle to decelerate it feels odd. Bear with me...like an oval rotational mass feeling...er lumpy. It has a new mid weight flywheel and new race crank (good quality). carb spits quite a bit and seems to run fairly rich. The B-Race is basically a curly expansion.
Any ideas....before I change exhaust, flywheel etc....

[stokky]

I had something a bit like this, turned out to be the chain too slack

Tightened chain up and all worked OK

[john.t5]

I had similar but it was more noticeable when cruising - fantastic description though 'oval rotational mass feeling' I think I described it as weird

Chain was slack also, gone once tightened up.

[peter357bikes]

If anything my chain is too tight...a proper t**t to get on and off..thanks for replying..any other ideas

[camel]

firstly you shouldnt get too much spitback with a reed conversion,im running two and neither bikes have much spitback so if your reeds are in good shape it sounds like its getting too much fuel....i take it your running a piston with windows?and its boost ported?

[peter357bikes]

yes I cut the piston and skirt as per the threads here and LCGB. but the spitback seems constant. But then again it is on my Imola and Rb...so i kind of accept that unless I have a too rich mix which is affecting my closed throttle?

[camel]

I don't really understand your description of the symptoms...are you saying the revs went shutting down when your closing the throttle?

[peter357bikes]

No more like engine braking but an uneven pulsing sensation almost like the power was on and off...