201tc-m erratic idle

[sean silverwood]

Hi folks.
great site this....right up my street
got my mates 201tc mtronic on the bench.
came in running like *s-worde.no idle whatsover and cutting out at the blip of throttle.
air filter and fuel filter had enough chip and dust in there to bed down four pet rabbits lol.
full service and carb re-set later and ive got it running pretty much 90% but still not right.
seems lumpy and hesitant at low revs and if you blip throttle it cuts out and floods?
ive advanced timing slightly and this improved it a bit.
any thoughts??
bag of *s-worde these...do they all idle like michael J fox on the drums or have i stumbled on a turkey?

 

[paragonbuilder]

I would do a pressure vac test to start. Did you rebuild the carb or just reset it?
It either has an air leak or fuel delivery issue. They actually run fantastic with a muffler mod and timing advance if everything is right.

 

[paragonbuilder]

How does the fuel line and impulse line look?

 

[paragonbuilder]

Oh, and welcome to a OPE!

 

[sean silverwood]

Look ok pal. only done a brief inspection though but yeah look fine.
its idling now but still rough.
il strip it down tomorrow and report back.
what i did notice when i did the flywheel was there is a bit of slack in the bottom bearings? could the seals be
knackered?

 

[sean silverwood]

I would do a pressure vac test to start. Did you rebuild the carb or just reset it?
It either has an air leak or fuel delivery issue. They actually run fantastic with a muffler mod and timing advance if everything is right.

just did a reset. to be fair it ran worse after the reset but then seemed to rectify itself somewhat.
top and bottom end it runs spot on albeit slightly rich by the looks of things but let it idle and its lumpy.
sort of sounds like its missing every third revolution.

 

[paragonbuilder]

If the bearings are bad, the seals will be leaking shortly if they are not already. But I would do a pressure vac test before tearing it down to verify if any other parts are leaking.

 

[sean silverwood]

is it worth buying MDG

If the bearings are bad, the seals will be leaking shortly if they are not already. But I would do a pressure vac test before tearing it down to verify if any other parts are leaking.

I shall report back tomorrow. thanks for your help. the problem be solenoid related?

 

[paragonbuilder]

MDG???
I believe the Solenoid only adjusts high side.
If your bearings have play, I'd start there.

 

[paragonbuilder]

My bad, I just looked it up. Mtronic adjusts idle as well. I haven't seen too many act up though.
But I'd still rule out other factors first