ignition blowing fuse and low rpm wot

ok i started by tryin to figure out why we couldn't go above 4000 rpm's in the process we have ruled out a few things on Don's list, gas is good changed fuel seperator did tune up, boat bottom clean, no water that i can tell, engines purrs like a kitten! just cant get above 4000 or like 43-44 mph which used to be 50-51. noticed the starter would act up occasionally so we would tap it and boat turned right over just little love taps on my ford....oh yeah
engine is omc502aphue its a 95 302 ford engine omc outdrive on a 190 horizon
forgot to put that info in... so we also needed to clean the pullys of rust so we did that and changed a thinning alternator belt. however now boat will not start when we turn the key to run it makes the gauges draw down then pops the ignition fuse. we are in the process of disconecting seloniod to see if thats the prob. any suggestion? also should you be able to freely turn the steering belt? like you can the alt belt? and finally we still have a low rpm issue we can't get the bolt to budge on the gas line into carb. i know there is a screen there and really want to clean it. but don't want to break nut... it's not a part that i can pick up in a day somewhere any help i'll take it.thanks, Melanie

Re: ignition blowing fuse and low rpm wot

fyi we disconected power to seloniod and its still pops fuse.... takes a few seconds but it draws the rpm gauge down and back into the 7000 #'s and pulls the battery volt meter down. it does this in the first position of key, we haven't tried to turn it over! what have we done now:facepalm:the only thing diferent from yesterday is we tightened steering belt and changed alt belt yesterday we were on the river havin fun... but steering belt was loose and sqeaking a little. HELP any thoughts? Melanie

Re: ignition blowing fuse and low rpm wot

update... not uncommon for boats the issue was totally unrelated to anything else going on....ingnition switch just went bad. replaced and were back to trying to figure out the wot only reaching 4000rpm's i guess the best advice is to follow Don's list, after a tune up is gas usually the culprit? does anyone know ? thanks, Melanie