cuts off with full throttle

Joined
May 25, 2004
Messages
17
1990 -70hp force at about 2200rpm will completely cut off.will instantly restart(has gas)and run O.K.Will never get much over 2200rpm.Using on pontoon.
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: cuts off with full throttle

When it dies,Check the plugs.<br />If they are wet, they are fouled, and it is probably too rich, or the fuel is contaminated with water (common this time of year).Check the entire fuel system (tank,carb bowl for water).<br />If the plugs have anything over 80hours, change them. It could be fouling-out due to rich condition, so check the mixture adjustment after changing the plugs. <br />Fouled plugs can be an indication of faulty ignition, but usually when the ignition fails, it wont restart that easily, or will take longer to cool-down to start.<br /><br />If the plugs are new looking but wet, it's water in the combustion chamber (fuel or coolant leak).<br /><br />If the plugs are dry, squeeze the primer,and see if it allows any fuel to be pumped (will be slightly mushy). If so, check the fuel tank vent. Loosen the gas cap slightly, and see if it cures the problem.Another cause of a spongy primer bulb is the fuel pump,which is a common failure on this and many other models. The fuel pump diaphram on these dual-stage pumps are suceptable to dammage by use of modern fuel formulas (Alcohol, methanol additives eat rubber). But a rebuild is a 20 minute job, and the kit is only about 25buks.<br /><br />.
 
Joined
May 25, 2004
Messages
17
Re: cuts off with full throttle

have checked fuel system all A OK Does anyone know about the sensor coil and how it works and how to troubleshoot it??
 

Oldsaltydog

Petty Officer 1st Class
Joined
Jan 27, 2004
Messages
322
Re: cuts off with full throttle

You probably need a good repair manual -- Clymer, Seloc, or factory. Check out this web site.
 
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