44MPG seems pretty poor

[GoldenFailure]

A10 plunger, finally seems pretty sorted, plug chops are grey, not thrashing the hell out of it, but killed £10.13 of juice in 74 miles. At £1.35 a litre thats about 44 to the gallon right? Is this normal? (because Ive read it should be 55-60) What are you guys getting?

[A10Boy]

Last summer I went to the BSAOC do in Kettering. I topped up at home then rode two up at 65 - 70mph down M42 - M6 - A14 to Kettering. Distance was 64 miles. I stopped at the petrol station and checked the tank level, it had gone down by only about 3 inches. After the do, we went home, topped up again which took about 1 1/2 gallons for a round trip of about 130 Miles. Thats about 85MPG in English. 

[bsa-bill]

Hi GoldenFailure
Andy has the right idea IMHO, you need to fill the tank right up and same on return, that's the only way to get an accurate reading as anything other is guesswork

[fido]

70 mpg seems to be about the going rate for riding at legal speeds one up on a solo, less with a pillion and lower still with a sidecar.

[GoldenFailure]

Tank was brimmed and mileage noted, then brimmed again and mileage noted as you say. Its definitely doing 44mpg. I even went out and did 20 miles with a mate on a modern japanese bike to compare odometer readings, but after 20 miles they were only 0.1 of a mile different

[Triton Thrasher]

If it's not running rich and the brakes aren't binding, I can't think of much you can do about it.

[chaterlea25]

Hi,
What gearing is the bike running??

John O R

[Triton Thrasher]

Does it have a very low compression ratio?

Could it just be worn?  You know, cams, bores, valves.

[t20racerman]

I'd go for over-rich every time. It is amazing how much fuel your bike can drink if it is too rich, but not rich enough for the performance to completely drop off. You'll need to do a proper plug chop to see. Go on a decent run to warm it up and then hold it as fast as you can on full throttle, for as long as you can. Whip the clutch in and hit the kill switch. Then check the plugs. Post a pic if you can.
My rather modified A10 will easily drink a (UK) gallon in 40 miles if you thrash it, but when running it in, in its iron head days, I got 93 mpg on a long run from Coventry to S Wales....