1997 90hp Force

I have a 1997 Force 90hp On a

I have a 1997 Force 90hp On a 1997 Voyager 20' pontoon. My question is when I push it to wide open throtle it cuts out a little if I run it this way for a minute or two it dies. Then its alittle hard to start but will start. It runs great at half throtle. Let me start by saying the gas that was in it age is unknown. But at todays prices hate to drain it. The engine is clean and looks to be well taken care of. Could it just be bad gas?
Nest question prop is showing signs of wear and is rough from water corrosion. At wot I get 20mph at 5300rpm. 13p prop could I bump to a vortec or Hustler prop 15p or should I stick with the 13p

"Throw your gas into your car

"Throw your gas into your car tank if it is more than 3 months old or of unknown age....bad gas is a major cause of outboard armageddon.

You can stick whatever prop you like on the motor....depends whether you need acceleration or top speed, your cruise revs need to be high enough to stop the motor oiling up, 2-strokes have a sweet spot so if happy with what you've got, keep to 13p.

If it was mine I would got to 15p so I was cruising at 20mph rather than WOT."

"Jerry, yes, your rpms sound o

"Jerry, yes, your rpms sound ok and I wouldn't go the cost of a new prop unless that one is really damaged.

Andy's correct about the old gas - at the end of each weekend I throw the boat gas in my truck - even mixed at 50:1 the truck don't mind and the outboard appreciates fresh gas each outing.

It sounds like maybe you are developing a clog in the carb(s). The dying out and then hard to start (plus maybe spitting some raw gas out the exhaust??) would be indicative of a sticking float valve - floods out killing ignition and making it hard to start until it gets some air back in and things dried out a bit..."

One thing I found the spark pl

One thing I found the spark plugs that our in it are not the ones the manual calls out for. In fact the plugs that our in it are not called out for any Force engine that my manual covers 1984-99.
Could that be a problem?

Carbs probably still need a cl

Carbs probably still need a clean but wrong plugs can hole a piston....

"Plugs are all about resistanc

"Plugs are all about resistance. Regardless of what "some guy" or even a shop can cross reference for you, specific ignition systems were designed to fire a specific plug within a given set of parameters.

Mercs/Yamaha's ingitions put out of 40,000-50,000 volts and fire NGK's - OMC's kick out between 30-35,000 volts and fire Champions for the most part - cross the two up and the motors can run like crud.

Go with what the mfg called for. They paid an engineer good money to design the system and pick a plug...."

The Manual Says to use NGK BUH

The Manual Says to use NGK BUHW. It had NGK BUZHW in it. The only difference I see is BUHW is a non resister and the BUZHW is a resister plug. Will it hurt to keep using BUZHW so it won't bother the radio? Or will the BUHW not bother the radio either?

No either plug would be called

No either plug would be called for depending on the application (as you note to prevent interference)..

Thanks for the help! Now if th

Thanks for the help! Now if the wind would stop(gust 35 to 45)and quit raining I could take it out for a test run.