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33 hp ski twin

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Bstrsdad

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Starts and idles well, full throttle on control, not enough rpm to plane. I think it should be some adjustment, but can't figure. Please help.
 
Full throttle on control. Does that mean the motor is also gong to full throttle? That motor should have plenty of power for any boat it is likely to be used on. Might not be running on both cylinders. They'll run surprisingly well on one cyl, just no power.
 
fdrgator said:
Full throttle on control. Does that mean the motor is also gong to full throttle? That motor should have plenty of power for any boat it is likely to be used on. Might not be running on both cylinders. They'll run surprisingly well on one cyl, just no power.
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Control lever is full forward, in forward gear, on water at lake. Thought it was spun hub, but I marked it and checked marks, realized the engine was just not running fast enough as it used to.
it was running smoothly, and ran for 45 min. No changes.
 
Simply hook up a timing light and see if there is spark on both.---------Test spark intensity to see if both will fire accross a gap of 1/4" or better.--------This motor has a dual ignition system with a coil , condenser and points for each cylinder.-------Quite common for a coil to be bad and shorting to the magneto plate.
 
Even simpler, remove and ground one spark plug wire and start it up & see how it runs. Then do the same with the other one. Chances are it will make no difference with one grounded and won't even run with the other one grounded. That is the good one.
 
This motor started out as a 28 hp in 62 to 64-Then became a 33 hp version last produced in 70 the problem you are seeing is the same on all of them.--------Check to see if it is running on both cylinders !
 
Thanks for everyone's input. I think the problem was as diagnosed,one cylinder.due to plug wire worn and grounding to head. Temporary fix, electrical tape, seemed to test better,also new plugs just because. How hard to replace plug wires?
 
Actually, it is 7mm. Stranded wire core. Non-resistor. No longer used on cars, but a really, really good auto parts store may have it. A good bet is one in a farming community, because it often is used on old tractors. AND of course an outboard or lawn mower shop. Can't stop without suggesting our host, marineengine.com
 
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