merc 4 wont fire - any ideas

[ollyit]

right got an 82 merc 2 cylinder 4hp aux, ran fine, changed the impellor took it for a blast on an inflatable dinghy, was fine then it got real hot (no tell tale) (1 minutes running time) turned it off rowed it back, guessed maybe the watertube maybe wasnt correctly lined back up with waterpump housing, dropped the leg and made sure, put it all back together and......

nothing, not seized, turns over nicely, just wont go - all vents open, its a gravity fed tank feeding the carb, throttle in start position, choke out, pulled out plugs there dry slighty caked in soot, oh and its not in gear

Have i missed anything obvious?!?! thanks guys

[Biggles]

Olly. Check the external fuel bowl.

I had an engine like that and once when it was turned up side down the small inlet valve on the carburettor float bowl came out of position and wouldn't let any fuel in. Thing is it should at least run for a little while then.

If your getting a spark must be the fuel. If your not getting a spark look at any sort of safety stopping mechanism the engine is fitted with.

[Nos4r2]

First step is to check it's not scored the bores when it overheated-give it a compression test. If it shows less than 90psi or significantly different readings then it's f'ked and not worth wasting time/money on.

Biggles is right about the fuel system-strip the carb next and clean it out thoroughly.

[ollyit]

thanks guys, ill ava nother look - might check to see if any wires anywere may have burnt out anywhere first, could be summink silly, as it has a kill button at the end of the throttle stick, hmmm
bloody well annoying well fancy a little blast today

[ollyit]

right can confirm both plugs and leads have a spark ran a wire from the block to the thread of the plugs, tested both leads by swapping also, gonna try again,

[Biggles]

Olly,

It has to be a fuel problem. You said the plugs were dry that indicates no fuel getting through.

That size of engine is pretty simple. So what I would do is trace the fuel system from the tank to the engine. Pull each pipe off as you go along and see if fuel comes out. Check the fuel bowl to see if you stiired up some crap when you turned the engine upside down. Take the float bowl off and see if fuel comes out.

Do all this over a large plastic sheet so if you drop any little bits you can find them. Trust me on this, I ended up hovering grass after losing a little part once.

Then get back to us.

Nick R.