50 yam not getting rpms

Went out yesterday only to find my 50 yam not wanting to tack out. Starting spittng and spuddering. Where do I start? Has been a faithful motor til now. It might just be worn out. 1988 model http://www.bassboatcentral.com/smileys/doh.gif

I'd start with the easy things first. Clean or replace the spark plugs, make sure the gap is correct and use a torque wrench when you put them back in. Check for air leaks in the rubber fuel hoses (and primer bulb) and also replace that old as heck fuel pump (probably the problem anyway). LOL. Also now's a good time to rebuild the carbs. Have you cleaned, or replaced the fuel filter recently?

Thanks Jerry

I am not much of a mechanic. But i will start working on those things you suggested. It does rev when not engaged.