49 Iron Head G80 starting problems

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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ajscomboman
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Re: 49 Iron Head G80 starting problems

Post by ajscomboman »

Duncan wrote:
ajscomboman wrote:
raffles wrote:Sam have you changed the petrol I have just purchased two bikes that would start and then run all over the place
then not start at all. Drained the tanks cleaned the carbs and now start first time and run beautifully.
Tony
Bugger you beat me to it Tony! I suspect water in the petrol which is a classic for this ethanol based fuel if it's left for long periods, you get separation and the water being heavier sinks to the bottom of the tank. Just had the same thing happen on a G12. My mower does the same thing, fill with fresh and it'll run like a Swiss watch.
Unlike your G15 which is more like a cuckoo clock.
Not even that!
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Taid
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Re: 49 Iron Head G80 starting problems

Post by Taid »

raffles wrote:Sam have you changed the petrol .......
Is there a recommended brand/grade which appears to be less subject to accumulating water?

Vaguely recall being told Esso Premium (or whatever they call their 'best' product was best, with low ethanol content
___

Now sold ... 1956 AJS 16MS Bitsa .. HSU 414 .. rebuilt/re-registered 1987
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dave16mct
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Re: 49 Iron Head G80 starting problems

Post by dave16mct »

Yes I was told Esso premium but last time I went I noticed it said it had 5% ethanol added. Usually it doesn't say anything on the pump.
Dave.
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Rob Harknett
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Re: 49 Iron Head G80 starting problems

Post by Rob Harknett »

Had a bubble of water in the mixing chamber a few times. Seen in the bottom cap when removed. Just turned the petrol on to flush any water out.
Reynard24
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Re: 49 Iron Head G80 starting problems

Post by Reynard24 »

I posted about a non-starting G15 in that section a week or so back that had plenty of sparks and (old) petrol - just drained the tank and filled with new fuel and away it goes. First time I've had a problem with stale fuel but I've done nothing else except change the fuel and hey presto!
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