High Speed Miss

[jamesprestridge]

Anyone have an idea why a Force 70hp outboard misses and looses power at 4000rpm and above? It runs great under 4000rpm, but when I hit the throttle to 4000rpm it stalls out then picks bask up. I have changed the trigger, switch box, spark pluggs, checked coils and cleaned the carbutrator. I am just at a loss.

 

[maxum247]

Re: High Speed Miss

If the engine dies momentarily when the throttle is opened and then recovers, check for a dirty or resticted main jet in the carburetor, water in the fuel or an excessively lean fuel mixture. Also check for vacuum leaks at the carburetor-to-intake manifold joint.

Several factors can cause lack of power and speed: Some of which are: Air leaks in the fuel line or fuel pump, a restricted fuel filter or a choke/throttle valve that operates improperly. Check ignition timing adjustment.