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[stinkwheel]

Of course, the classic reason for only starting with EZ start spray is poor compression. Obviously it's been rebuilt so this shouldn't be an issue.

[Daiwiskers]

It would have to be drasticly down on compression to start on ether then not continue to run on petrol
If it's a compression issue on a rebuilt motor I would suspect valve clearances or rings fitted incorrectly
Try a dry then wet compression test to find out which
Paul bw mentioned ignition timing earlier, try this first then compression test if these both come up good it has to be weak spark or fuelling air leak on manifold ? Possibly but unlikely as it will run on both cylinders but not at same time

[Daiwiskers]

I hate to say this but having slept on it

Oh hell here goes

How are the spark plugs

New ?

Gapped correctly ?

Right type ?

I can't think of anything else that we haven't covered

Sorry I had to ask Dai

[Creaky45]

The maggy is away being checked once again so we won't know much for a while but I will keep you all posted. The compression, rings and pistons all seem fine but we could try a compression test. Also if we get it running on one cylinder I will put my strobe timing light on to prove the timing is correct and advancing with revs. Thanks to all for your ideas. Watch this space.

[Adrian]

Uneven wear on the magneto cam ring?

A.

[Vince2]

Hi, I take it from the first blog that this is an SR2 mag?. If so its probably tracking in the distributor area. Vince

[Creaky45]

Adrian and Vince, Not sure what you mean but Mike has sent the maggy/dist off to another highly recommended maggy fixer and we will have to presume he will either test it thoroughly on the bench or find a fault and fix it. I will let you all know the results but it may be a few weeks yet. I could not find a fault with the size of the spark running it on the bench and it has been 'repaired' once already by someone else.

[Lou E]

Been here....done this...check top dead center with a pencil down the spark plug hole against the crank sprocket timing mark....if they don't match up the pin I sheared on the tapered shift inserted into the end of the crankshaft....all the marks will line up but the crank shift will be out of time with its sprocket...don't ask me how I know....

[Creaky45]

Lou E, That sounds interesting but I need more detail. So you are saying that with the piston/s on TDC you found the mark on the crankshaft pinion was not exactly at 6 o'clock. So you made a new mark at the 6 o'clock position and then got the two lines on the cam sprockets pointing horizontally in and in line. So the crankshaft sprocket must have gone on wrong which I thought impossible as surely it has a woodruf key. What do you think happened. Did yours have a key and is the shaft tapered?

[Creaky45]

Fixed at last. As half suspected it turned out to be the maggy. Because it had been overhauled by an 'expert' and it showed a good spark we had to presume it was ok. But Mike sent it to another recommended repairer who found the insulation on the windings breaking down presumably when hot. Apparently there are different types of insulation and this one had the wrong type. ?? When we got it back you could feel jerky resistance when turning it by hand which I recall we did not have previously. It should not spin freely but you should be able to feel the pull of the magnets. I had tested the coils on the bench ok but of course it was impossible to simulate riding conditions. Anyway thanks to this bloke all appears to be well. Thank-you all for your suggestions.