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Carb blowback #154595
06/06/08 6:15 pm
06/06/08 6:15 pm
Joined: May 2006
Posts: 151
Warrington, Cheshire, UK
TriVin Offline OP
BritBike Forum member
TriVin  Offline OP
BritBike Forum member

Joined: May 2006
Posts: 151
Warrington, Cheshire, UK
Hi

I've just got my Comet together after fitting a new piston. It started first kick but it appears to be blowing back out of the carb. What should I check first do you think?
I checked the timing marks carefully, set the timing and electronic ignition as per the instructions, checked valve clearances.
I'm stumped

Dave


Dave
Tiger 100SS 1966
T120V 1972
Vincent Comet 1952
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Re: Carb blowback #154596
06/07/08 3:42 am
06/07/08 3:42 am
Joined: Dec 2007
Posts: 259
australia
D
douglas Offline
BritBike Forum member
douglas  Offline
BritBike Forum member
D

Joined: Dec 2007
Posts: 259
australia
I'm afraid it sounds like valve timing will be out by a tooth or too. Oh well!! off with the timing cover. No, i'm not sadistic!! Douglas

Re: Carb blowback #154598
06/12/08 11:54 am
06/12/08 11:54 am
Joined: Aug 2001
Posts: 7,672
scotland
triton thrasher Offline
BritBike Forum member
triton thrasher  Offline
BritBike Forum member

Joined: Aug 2001
Posts: 7,672
scotland
Does it blow regularly at half engine speed or occasionally sneeze?

Sneezing is usually a weak pilot mixture or slide or inlet air leak.


Amateur Loctite enthusiast.
Re: Carb blowback #154599
06/13/08 3:37 pm
06/13/08 3:37 pm
Joined: May 2006
Posts: 151
Warrington, Cheshire, UK
TriVin Offline OP
BritBike Forum member
TriVin  Offline OP
BritBike Forum member

Joined: May 2006
Posts: 151
Warrington, Cheshire, UK
Hi Guys

Things have moved on a lot since last week.
Before having a chance to do anything with the timing my mate and I went off to York last Saturday for the Vincent Rally where we were advised to set the cams 'on the rock' at TDC just to get it close. Then my mate found an old article in MPH from 1968 which stated that the diagram for the Comet valve timing shown in Paul Richardson's book, which I had been using as my guide, was in fact 50 degress out! So we were not even near to correct. In fact I'm surprised it even started.
Anyway after doing as advised it started and ran pretty good today. However, I would like to now fine tune it using a DTI as you have suggested here. Could you explain the procedure for me or direct me to somewhere where it is written down.
First I must get a DTI. Should I get the plunger type or the finger type? Am I going to need to get a magnetic base or what.

Thanks


Dave
Tiger 100SS 1966
T120V 1972
Vincent Comet 1952

Moderated by  John Healy 


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