Newbie questions

[peebles24]

I just purchased my first power boat. It's a 1986 Baja Islander 180 with a mercruiser 140 I/O. I took it out the other day with a full tank of fuel, 2 180 lbs. people and a 40 lbs. person. At wide open throttle the Garmin said I was doing 34 mph and I was running dead on 4000 rpm. I had the trim all the way down. What should I do the prop is 19 pitch if thats what the number on it means.

Thank you
Chad P.

 

[maharg]

Re: Newbie questions

Sound about right, you want to run trim up at high rpms. My 140hp does 31 at 4800 with a 17p

 

[peebles24]

Re: Newbie questions

4000 just sounds like it's not really opening up I thought a 4 cylinder would turn more than that.

Thank you,
Chad P.

A moderator may want to move this I meant to put it in propellers section.

 

[woosterken]

Re: Newbie questions

the pocket service guide that came with my '74 merc , says the max rpm at wot is
4200 to 4600 for the 140 hp.

hear is a good article about trim.........

http://www.clubmarine.com.au/internet/clubmarine.nsf/docs/MG19-2+Technical

woosterken

 

[tcgobucks]

Re: Newbie questions

I just purchased my first power boat. It's a 1986 Baja Islander 180 with a mercruiser 140 I/O. I took it out the other day with a full tank of fuel, 2 180 lbs. people and a 40 lbs. person. At wide open throttle the Garmin said I was doing 34 mph and I was running dead on 4000 rpm. I had the trim all the way down. What should I do the prop is 19 pitch if thats what the number on it means.

Thank you
Chad P.

Run the trim up to at least halfway once you're on plane. I'd guess you'll gain 300 or so rpm and 3 to 4 mph. That is a nice engine, I would guess you'd be over 40 mph with no problem if it's propped right....aluminum or stainless?

 

[peebles24]

Re: Newbie questions

Very informative thank you I need to play with the trim I have not done this yet, I am going out friday though.