Power Head

michael323i

Recruit
Joined
Jun 4, 2012
Messages
1
Hi there i would be very greatfull to anyone out there who can help me and my new boating friend .... i am U.K based and just bought a 120 HP Johnson outboard from a guy on ebay , now the engine was in a kit form ( bad idea ) how ever i am an ex-toolmaker / machinest by trade and thought it would be no problem to put back together. The power head was complete , so i looked at the bores/pistons (no slap/good fit ) and what appeard to be nice even hone marks, so i cleaned the heads up and bolted them on , put power head back on ect ,cleaned carbs up & checked the read valves for day light ect..tried to start up and behold it would'nt start ... i had a marine engineer around and he seems to think it's not sucking the fuel up , but if you get an house hold atomizer with 50:1 fuel in it & squirt neat fuel in the carbs it will fire up for a few seconds untill the fuel is spent, i have thought about getting my electric fuel pump of my MK1 3000 Litre Capri and putting that straight on the fuel line too, now does that mean the crank seals are worn out because it wont suck fuel ,bearing in mind the priming bulb is hard , as i don't know much about two strokes,the choke is putting fuel in the back of the carbs too. . I have given it a compression test and found readings above 110 PSI , looking at this USA forum two strokes are complete nightmare and seem very tempermental ....... please help us !
 

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
Re: Power Head

You can always pull the fuel line off where it feeds into the manifold that supplies all the carbs (output of fuel pump) and crank it.
It should gush fuel out.
If it doesn't look at the fuel pump and pulse line that feeds it.

Pump primer with line disconnected, fuel should gush out.

If it pumps OK, look at clogged idle circuits in your four carbs.

Clean carbs thoroughly.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Power Head

No way man, just high maintenance :)

and only half the nightmare of a fourstroke! and as daselbee said....you need to verify the fuel delivery system, both for flooding and fuel starvation. ( 90% of the time the carbs need a good cleaning and re-kit....and that should be done on a motor/carbs that couldnt be tested before purchase anyway) jmo
 
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