No progress today as I was out riding my 350 Bullet (starts first kick). It has occured to me that I probably disturbed the ignition timing while removing the exhaust cam to get behind the timing pinion to remove it. Tomorrow the plan is to first check the ignition timing. If that is out, then to re-set it and see if that restores the ability to start the engine. Then to try a new plug and see if that makes any difference. Finally to take the SR1 to a friend who restores magnetos and dynamos to see if he can check out its functioning.
Thanks again for all the contributions - I might have given up otherwise.
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For Royal Enfield owners and enthusiasts
- Wed Jul 15, 2015 4:57 pm
#49413
- Wed Jul 15, 2015 8:12 pm
#49418
If you suspect the ignition timing might have moved because the timing pinion and exhaust cam were removed, make sure the inlet cam is timed correctly too, as, assuming this cam was left undisturbed and the ignition timing is out, then the inlet cam timing will be out too.
- Thu Jul 16, 2015 5:03 pm
#49431
Re-timed the ignition - it was way out. I had removed the inlet cam in order to line up the valve timing dots and must have moved the idler pinions. It now starts again, but still only runs when the choke is completely closed. It ticks over reliably, but as soon as the air lever is touched it cuts out, even when it is being revved. My feeling is that there is a significant air leak somewhere for it to be affected when the main jet/needle jet are in operation. Tried a new spark plug, but no improvement. At least I am back to square one.
- Thu Jul 16, 2015 8:17 pm
#49436
if it sucking falls air for this to happen, your carburetor should be hanging close to loose.
you say you cleaned the idler circuit out;
but what your describing still sound like a idler circuit that is clogged.
did you remove the plug in the back?
other wise try to get your hands on another carburetor, that comes from a bikes that runs normally.
if it sucking falls air for this to happen, your carburetor should be hanging close to loose.
you say you cleaned the idler circuit out;
but what your describing still sound like a idler circuit that is clogged.
did you remove the plug in the back?
other wise try to get your hands on another carburetor, that comes from a bikes that runs normally.
- Sat Jul 18, 2015 2:41 pm
#49456
Mauri and Whisperer, you were right! I decided that if the pilot jet was the cause of the problem, it might be better to have a Monobloc where the pilot jet can be removed for cleaning and checking, so I ordered one from our hosts with the original specification yesterday afternoon. It arrived today (I don't need to tell you about how good that is for brilliant service)and just fitted it. The bike fired up second kick and the air lever could be opened straight away. It responds to the pilot screw adjustment and sounds like its old self again. I have yet to road test it, but already have a smile back on my face. Bl***y ethanol! Thanks again to all who kept me on the straight and narrow.
Don
Don
- Sun Jul 19, 2015 1:07 pm
#49466
I'm pleased you sorted the problem, perhaps there's something to be said for authenticity!
It might still be worth hanging onto the Mk1 concentric as a spare and getting it ultrasonically cleaned to clear out the pilot hole blockage. The present day Amal producers have belatedly recognised the problems with the Mk1 Concentric and launched a de-luxe (Premier?) version with detachable pilot jets, aluminium bodies instead of zinc alloy and hard anodized throttle slides.
Regards,
A.
It might still be worth hanging onto the Mk1 concentric as a spare and getting it ultrasonically cleaned to clear out the pilot hole blockage. The present day Amal producers have belatedly recognised the problems with the Mk1 Concentric and launched a de-luxe (Premier?) version with detachable pilot jets, aluminium bodies instead of zinc alloy and hard anodized throttle slides.
Regards,
A.
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