70 Johnson Only Runs With cover off

[sat1962]

Firstly a brief summary of the situation......this is a motor that sat for 10 year until this summer when I am trying to revive it....I have cleaned and rebuilt the carbs, new fuel lines, new gas tank ( not running off built in tank) new exhaust cover gasket, new head gasket.

Yesterdays lake test would not run at wake speed only over 4000 rpm's. I adjusted the floats on the carbs per Joe Reeves post. Took it out this afternoon and it was going great at all speeds....even wake speed. Stopped for lunch then started her up and......it would die when put in gear...carbs were flooding.

Only way we could get back to the launch was to run it with the engine cover off....btw I have been testing it with the carb air boxes off.

Any advice much appreciated??

 

[wildmaninal]

Re: 70 Johnson Only Runs With cover off

If you are having to run it with the cowling off you may have an exaust leak. Or your carbs are still out of adjustment one.

What motor are we talking about?

 

[sat1962]

Re: 70 Johnson Only Runs With cover off

this is a 1988 70 johnson i have floats tipped up to lean them out but still loading up i just put new exhaust cover gasket on how do u check fo ra leak

 

[wahoo 16]

Re: 70 Johnson Only Runs With cover off

check you idle jets , may have sucked in loose foam or other spec and plugged low speed orifice, from running with no cover box.

 

[sat1962]

Re: 70 Johnson Only Runs With cover off

ok thanks ill check them so i should put air box on before running it again?

 

[wahoo 16]

Re: 70 Johnson Only Runs With cover off

you should have covers on for wot (wide open throttle)

 

[sat1962]

Re: 70 Johnson Only Runs With cover off

would it make it load up do u get more air in carbs with cover on than off? i been running it this way to see whats happenning in carbs i went and checked low speed jets seemed clean any other thing that could cause this

 

[sat1962]

Re: 70 Johnson Only Runs With cover off

let me also add it seemed like it was using lots of fuel ran wide open throttle back and it was about ten minutes and about 2 gallons of gas.......