Wednesday 8 October 2008

Outboard engine will not run


I have an outboard engine which hasn't run for a few years. It's a Johnson Seahorse 4 horsepower 87cc twin cylinder jobby. Recently Bones let it be known that she was in the market for such a machine, so I got it out of the garage, put some petrol in, and tried to start it. And tried again. And again. Nothing. Not a cough. No sign of life whatsoever. I took the plugs out and cleaned them; and then checked for a spark when I pulled the cord. Yes! So it must be a carburettor fault. Perhaps the petrol/oil mixture (it's a two-stroke) had turned to jelly and was blocking the way for the nice fresh liquid stuff I'd put in. I unscrewed the float chamber to check that fuel was at least getting there - and got petrol on my trousers. So far so good. Now I'd have to take the carb off the engine and investigate further. This was easy: pull off the fuel pipe and undo a couple of 7/16 nuts. Er ... now what? I could see the choke butterfly valve, and, beyond, the throttle butterfly ... but what should I do? Ah. There was the rich/lean idle adjustment screw. I'd read somewhere that you have to screw this in to note the number of turns so that it could be replaced in the same position. I screwed it in and counted all of three quarters of a turn. Then I unscrewed it completely and was surprised to find a needle on the end. I was expecting the needle to be somewhere else. (No, I'm certainly not an expert on carburettors!) Perhaps there is another needle elsewhere. But where? I couldn't see anything wrong with the needle I'd removed, so I put it back and left the carburettor on the kitchen table for a few days. (Mmm. Nice smell.) Then I thought: I know, I'll put it back on the engine and try again. Well it's worked with other things in the past.


So I did ... and ... still nothing. I even mounted the engine with the prop in the water butt so that if it fired up it would have plenty of nice cooling water. Actually the water, when disturbed, turned out to be full of rather rusty scummy stuff, but that didn't matter as there was still no hint of life. Grrr. Now Bones has found an outboard engine that works, and I have put mine, dead, back in the garage. And I didn't even take a photo of the semi-dismantled carb.

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