Hi Adev
Mad

project fits the bill - but interesting if it works. If it does I'll post details, that way I won't have to hang my head in shame if it fails

.
Had another idea

- must be the weather - If I squirt compressed air into my cheapo generator 4 stroke it will only power every other stroke, but if I change the cam reduction gear to make it 1:1 then it should have power every stroke - and it may be OK with the shorter valve opening times as the gas volumes will be lower but twice as often.
I'll have to think on it some more but it sounds like a sort of plan .. .
Other thing is, if it is going to cost me £200 for a delivered Clarke alternator and this petrol generator is £175 including IC engine then it seems like a no brainer, even if I can't get it to work with 4 stroke engine I am no worse off - just some time spent - which the government hasn't seen fit to tax yet !
Have some other inquiries out for air motors so I'll finally decide when I know the costs involved.
Best Regards
picclock
Hi kwackers - alternators normally have brushes to excite the rotating coil. Often mounted on the end of the alternator. They only carry low current, and by varying the current you can control the alternator output. Brushless ones are sneaky, they control the current in the centre winding by inducing it from another coil on the shaft.