Runs for a second the stops. Help

[electrajohnt]

Thanks all for your contributions.
I have now the cleanest carburettor in England - but, turned out to be valve clearance on the right hand cylinder. Runs ok now, noisy with the old Meggas on it. For completeness I would still like to do a rough check on the ignition timing, anyone know what distance the points open before tdc when measured on the stroke.
Regards JohnT

[Mick D]

Hi

The Owner's Manual, (Pg 41), says 11/32" BTDC fully advanced - (don't be fooled by the magneto, it's the same for the coil)

Regards Mick

[electrajohnt]

Thanks Mick

[G15 Roy]

Lots of help may be time to join the club as you come up as none
Member.

[Mick D]

John T

Maybe an idea to contact Eamonn regarding your visible status - I assume you are a member having joined the forum in May in 2019

Regards Mick

[SPRIDDLER]

I've never owned nor worked on a twin so I need educating by the twin aficionados as to why, if the tappet clearance is wrong on one cylinder, it doesn't just run on the other cylinder?


(All my Heavyweights have always run perfectly well on just one cylinder ).

[Eamonn]

....Maybe an idea to contact Eamonn regarding your visible status....

Membership expired on 1st Dec 2020. Time to renew!!

[robcurrie]

I've never owned nor worked on a twin so I need educating by the twin aficionados as to why, if the tappet clearance is wrong on one cylinder, it doesn't just run on the other cylinder?


(All my Heavyweights have always run perfectly well on just one cylinder ).

It could be that there is blowback through the carb if the inlet valve is leaking on one cylinder. My twin carb CSR will probably run on one cylinder under the same conditions.

Rob C

[electrajohnt]

Yes it was the inlet tappet that was tight so maybe that was a problem. I will say that once the clearance was adjusted it still sputtered a bit but with some judicious juggling of the throttle it eventually settled down and I managed, with adjustment to the pilot screw, get a nice even tick over with no spitting when the throttle was opened. So, having given this some thought after my last post:
1) The valve clearance was tight, not sure how tight, having discovered 0.008” would go nowhere near it I just carried on an adjusted it, same with the exhaust on the same cylinder.
2) Even though I could blow carburettor cleaner through to emerge from all the places it should (7&8 included) the air screw is only out half a turn to give a nice even tick over with no spitting when throttle opened. Something still not right there I guess.
3) The fuel I am using is of dubious vintage, mixing of various drainages from other bikes and siphoning from my common user. Although my Velocette kicked up, and back, on it so cannot be that bad.

Anyway, it is certainly better than it was. Just need to torque the heads back down and recheck the tappets as well as a rough check of the timing.

Regarding the renewal of membership, I did try last night but the temporary?.? ( why temporary if it only ran out beginning of last month) Number given did not seem to work so I sent an email asking for assistance.

Regards
JohnT

[SPRIDDLER]

I've never owned nor worked on a twin so I need educating by the twin aficionados as to why, if the tappet clearance is wrong on one cylinder, it doesn't just run on the other cylinder?


(All my Heavyweights have always run perfectly well on just one cylinder ).

It could be that there is blowback through the carb if the inlet valve is leaking on one cylinder. My twin carb CSR will probably run on one cylinder under the same conditions.

Rob C

Ta Rob.

Cuh! Twins, eh? Who'd have 'em?