Low wot rpm's on my 1987 150hp merc

[angles4lyfe]

Hi i recently bought a new boat its a 18ft 1985 hydra sport with a 1987 v6 150hp merc on it. the boat had been sitting since 1998 and hasnt been turned on since. so i went ahead checked to see if it would turn over and yes the previous owner and sprayed oil in to the piston so it wasnt stuck. i checked the compression 120 on all cylinders. I went ahead and rebuilt the carbs, put in new spark plugs , check if i had spark and I do and put in all the fuel hoses new because they were bad. well yesterday i take the boat out to try it out, it turns on and idles great. i drive it down the channel perfectly with no prob, once i get to the en of the channel i take it all the way down to WOT and it gets on a plane immediately but it wont pass 3500 rpms. it seems to me like if i was only running on 4 pistons because it would ocasionally miss and shake a bit and actually feel like if it had no power. can anybody help me out with this?

 

[andy6374]

Re: Low wot rpm's on my 1987 150hp merc

You checked spark on all cylinders?

 

[angles4lyfe]

Re: Low wot rpm's on my 1987 150hp merc

yes ive check spark on all cylinders and they all have spark. im going to go ahead and do a timing and sync one the motor

 

[KCLOST]

Re: Low wot rpm's on my 1987 150hp merc

This could still be spark related, but first I would clean the carbs. Sitting that long has bound to leave gummup problems..... That is something that is almost a for sure deal for 7 years of sitting...

 

[KCLOST]

Re: Low wot rpm's on my 1987 150hp merc

Let us know...

 

[angles4lyfe]

Re: Low wot rpm's on my 1987 150hp merc

yes the carbs have been cleaned and checked. i went ahead and did a timing and sync and it was way off timing. it sounds way better now in idle just got to go out and test it. i will repost an update. thanks