MZ/MuZ Riders

Hi
I have a problem with poor low speed running after heavy acceleration followed by heavy braking (The two often go hand in hand!) on the Mastiff.It has the symptoms of a semi-blocked pilot jet -won`t idle, coughs and splutters at small throttle openings, fine at larger ones.
It doesn`t sort itself out, but draining and flushing the float bowl (Which takes just a few minutes) gets me running fine until the next time.
I had the carbs off several months ago not because of this but because it was about time i did, and to do some recommended jetting changes, so they obviously had a thorough cleaning then.
I recently stripped and cleaned the fuel tap assembly a flushed the tank out which hasn`t made any difference.
Any thoughts please anyone?
Cheers

Are you running a small micron filter between the tank and carb? The only thing I can think of that has those symptoms and can be fixed by removing and draining the float bowl is dirty fuel plugging the pilot. It doesn't take much. Try a filter if you don't have one.

Hi

Thanks for that.
No, it`s never had a filter but whatever is causing the problem i feel must already be `hiding` in there and only rears its head after some heavy duty acceleration!
It`s actually got a larger than original sized pilot jet than original so should be less inclined to block!
I`m curios as to the `mechanism` by which this happens, if there is muck in there it should always be a problem not just after its been `given a big handful`surely?

Cheers

even when running ethanol free GAS the big problem with my bikes..
has always been crud in the fuel or the recommended plug is wrong
then bad choice of jet sizes

old /2 BMW's seem to run poor from weak spark if the mag is not working proper(out of adjustment)
installed a 12volt test. point and coil system on one and the difference was much better
it let me know the carbs were OK
Dave

edfmaniac wrote:Are you running a small micron filter between the tank and carb? The only thing I can think of that has those symptoms and can be fixed by removing and draining the float bowl is dirty fuel plugging the pilot. It doesn't take much. Try a filter if you don't have one.

Hi

Certainly short-term i seem to have sorted the problem by draining the float bowl via the drain screw, blasting carb cleaner down the fuel inlet and draining again.
My problem is fitting a filter in the short gap between tap and carb without kinking the line.
I got hold of a Polisport In-Line Fuel Filter which is short enough, but being plastic, the bore looks too small to pass enough fuel in extreme demand, or is this not an issue?
I`ve fitted filters to numerous bikes easily over the years, what do other people use on their Mastiffs/Baghiras?

Cheers

Hi
That`s an interesting take on it, thanks.
I had the carbs apart less than a thousand miles ago and found nothing untoward, and the bike has done only 16,000 miles.
The poor running doesn`t settle down or go away until until i flush/clean.
Have just measured the bore of this Polisport filter and it`s only 3,6mm diameter (tube bore 6mm) Is this large enough to flow enough fuel?

Cheers

I`ve at last sorted this out!
After putting another in-line filter on without any change, i thought of one last thing before having to bite the bullet and take the carbs off.....
Took out the slow running adjustment screw(6) and blasted aerosol carb cleaner up the hole it came out of, and put the screw back in; it`s been fine ever since!!!
Thanks for all your input chaps.