90 hp works in reverse and misfires neutral

[crookedbilly]

New to boating i had a used 90 hp serviced and it went like a dream for an hour. (the guy who serviced it has left the province last week after his wife threw him out). On second day my son revved it very hard from the dock on a 20% full tank. It died after 20 seconds. After 10 mins i could get it to go in neutral and a bit in reverse, but as soon as i go in to forward it stops...seems not to want to rev high. Could I have sucked up some dirt from the nearly empty tank? Is this something i can fiddle with (I know nothing) or is this another drain on my dwindling dollars? Even in neutral today it seems to misfire a lot. All ideas very welcome! Heeeeeelp!!

 

[moparman]

Re: 90 hp works in reverse and misfires neutral

It's very possible,especially if you don't have an inline fuel filter between the pump and carbs. Do you have any history on the service that's been done to the motor? If the motor is new to you ,and you have no records of what service has been performed on it you need to start from scratch, [this is MY opinion ,and what I would do to start out]. First change the lower oil,change the water pump ,fuel pump diaphragm and start off with fresh plugs,and a cheap inline fuel filter between the fuel pump and carb and by doing these few things you have a good start to your season knowing WHEN these basic service issues were last done. These items I mentioned are normally done every two to three years as preventive maintenance to help keep breakdowns on the water to a minimum,[but with a boat ANYTHING CAN AND WILL HAPPEN!]Back to the problem you have now, look at the remaining fuel in the tank to see what shape it's in ,how long has it been in the tank,is it old ,trashy looking? If the carb[ s ] are stopping up ,it will lean the motor out and very easily could melt a piston, so find the problem before that happens ! Keep us posted as to what you find ,so that some one else will learn from this and maybe avoid this same issue.Hope this info helps.

 

[crookedbilly]

Re: 90 hp works in reverse and misfires neutral

I looked at the fuel which is 9 months old and looks as if it has water in it. Will do the jobs listed next weekend and tell you the result. The other things were done I think, though the guy doing it could be unreliable. Thanks