Flooding/bogging at low Speed

[boxofbits]

I’ve got a Group 4 barrel I’m playing with at the moment for my road bike , the problem is it just wants to flood or bog out all the time at the bottom end – and stalls if you get to any junction, tried a different jets and different carbs with no difference. Also it’s a right Bum to start – without flooding it . When it does goes and hits the mid-range it does go it’s like a rocket, but soon as you let off it doesn’t want to tick over even with a little throttle. I am running it with standard timing 17 deg and a midweight flywheel with no fins . Maybe advanced retard box may sort it out. Any ideas where to start looking or changes

[drunkmunkey6969]

I’d guess it’s got astronomical inlet timing...have you measured it?

[mick1]

or the choke's stuck on.......

[boxofbits]

Yep inlet is massive,piston also has more off the inlet side.

[drunkmunkey6969]

You can fit a standard piston back in, but if floor of inlet is still too low at that point...

[holty]

would fitting a reedvalve help if the inlet timing is so big ?

[drunkmunkey6969]

would fitting a reedvalve help if the inlet timing is so big ?

Yes, would serve as a bit of a ‘patch up’ job to get the motor running cleaner and cure the current issue. But could then risk stifling top-end performance, unless ported to match.

Where do you draw the line though? Might be better to stop now and say: Is this the right cylinder for me?

If not then what will it cost to: a) do a patch up job, vs b) fully sort the issue properly, vs c) sell it and buy a BGM kit...lol

[boxofbits]

Yep going to give up for sale if any one fancys a bit of tinkering. muggello 205 barrel rm piston mb large head (runs with no cowling) bespoke exhaust goes wrong side .requires a 110 rod with 18mm end ape rod does it. £300. All in will post Exhaust is worth that alone and the head cost me 200.pm me if intrested

[boxofbits]

I keeping the crank

[HotPearlSnatch]

Just before you totally give up where was the timing set on this beast?