Whaler Central - Boston Whaler Boat Information and Photos

Posted by Chichibio62 on 12/26/12 - 12:05 PM

hello to everybody I'm new to this site and I greet all.
I have a montauk 17, 1980.
it mounts a yamaha 115 hp in 1991.
I need your experience boston whaler.
How fast should do with my engine?
propeller that I have to install?
that diameter?
that pitch?
I've tried a 3 blade step 17 (30 kn) but 4400 rpm
I tried a 4 blade 13.25 diameter x 13 pitch (30 kn) but 5600 rpm
thanks for your help that you give me.
Happy New Year to all.
piero

Posted by Slickityd16t on 12/26/12 - 12:06 PM

What are the brands of thses props? Not all pitches 13, and 17 pitches are the same

Posted by Finnegan on 12/26/12 - 1:24 PM

I don't know much about Yamaha 115 2-strokes, but I have a very similar 1979 Montauk with a Mercury 115 L-6 2-stroke, 2.0 gear ratio, and it turns a Mercury 20" Laser II prop up to 5700 RPM at around 53 MPH.

I would have your engine checked out. It does not seem to producing enough power.

Posted by tedious on 12/27/12 - 7:50 AM

Hi Piero and welcome to Whaler Central!

With a Yamaha 115 on there, and everything working properly, you should be able to get at least 40 knots, probably 45. Is the bottom of the boat in good condition? A rough hull can create a lot of drag.

Also, where is the motor mounted? Many motors were mounted all the way down on the transom, and with a modern prop you'll be able to lift the motor up to improve speed and handling.

Tim

Posted by Tom W Clark on 12/27/12 - 8:04 AM

Actually, a Montauk with 115 HP should be good for about 48 MPH (42 knots).

The 1991 Yamaha 115 has a 5500 RPM redline and a 2:1 gear ratio. Either of the props tried should have had the motor far exceeding the redline so something is wrong with the motor.

Working properly, the motor would make good use of a 13-1/4" x 19" Stiletto Advantage or 13-1/4" x 20" Yamaha Performance Series 3-Blade propeller.

You do not want to use a four blade propeller on a boat like that.

Posted by Chichibio62 on 12/27/12 - 10:16 AM

Thank you all for the answers that you gave me.
the hull is smooth as a baby's bottom.
the engine sings perfectly.
I treasure everything I have said and see if the motor is in order.
thanks again
I will keep you informed.
Happy New Year again
piero

Posted by Slickityd16t on 12/27/12 - 7:22 PM

Have you recently done a compression check or cleaned the carbs?

Posted by Chichibio62 on 12/30/12 - 5:41 AM

x Tom W Clark:
are you sure of stiletto advantage 13-1/4 x19" ?
because I found one used!!!!
soon will insert pictures of my montauk reconditioned.
where do I put them?
on my personal page?
king regards
piero

Posted by Chichibio62 on 12/30/12 - 9:22 AM

#10

I am committed and we are able to publish pictures of my adventure.
now I have a personal page full of pictures.
thanks to all for giving me the opportunity to be part of this amazing site.
piero

Posted by tedious on 12/31/12 - 5:46 AM

#11

I only see 1 picture so far. It's a little confusing getting a personal page set up. Your boat is beautiful! I love the wood.

With the added material and the kicker motor you probably have a lot more weight than a stock Montauk, so that will reduce your speed some.

Happy New Year!

Tim

Posted by Chichibio62 on 01/01/13 - 8:09 AM

#12

Thank you, I've uploaded all the photos of the work done in 6 months.
I saw them.
then the next day they were gone.
I'll try again.
happy new year
piero

Posted by Joe Kriz on 01/01/13 - 10:47 AM

#13

Chichibio,

It looks like you uploaded them and then deleted them.
Once you upload them, you can't delete them or they will be gone.

Posted by Chichibio62 on 01/08/13 - 2:38 AM

#14

Hello everyone, I'm sorry if I have not answered right away but I'm just back from London for a well deserved vacation.
joe x
is, in fact, I was wrong, I'll try 'to load them again to have your opinion on the work I've done.
for the motor maybe I put too low.
someone can tell me exactly how it should be mounted?
thanks to all and happy new year
piero

Posted by Joe Kriz on 01/09/13 - 11:24 AM

#15

Chichibio,

It looks like you uploaded abouit 22 photos and then you deleted all of them again.
The photos will not work if you delete them.

I mentioned this to you in post #13 above but I guess you are not understanding this.

Posted by Chichibio62 on 01/10/13 - 2:48 AM

#16

hello tom, I have uploaded all the photos and I verified that they were there.
were all there!!
I left the site and I redid the login: there were all.
this morning there are no more!
I have not deleted.
but who has entered the picture with the logo boston whaler?
I have not inserted.
I can not understand why.
however, tom, we come to the most 'importanti.quanto must be more' high-cavitation plate with respect to the bottom of the hull?
thanks piero

Posted by Chichibio62 on 01/10/13 - 11:20 AM

#18

CHEERS!!
I THINK TO BE ABLE TO UPLOAD THE PICTURES!
PIERO

Posted by Tom W Clark on 01/10/13 - 11:43 AM

#19

That Yamaha should be mounted as high as it can go using the lowest of the four sets of bolt holes in the motor.

Posted by Chichibio62 on 01/10/13 - 12:12 PM

#20

thanks,tom.

as soon as I try to raise it.
then let you know.
regards
piero

Posted by Chichibio62 on 04/16/13 - 5:31 AM

#21

hello everyone, hello tom.
the engine had a IGNITION COIL ASSEMBLY burned.
I still have a hole to get up.
for now I have reached 43 mph.
thanks to all

Posted by Finnegan on 04/16/13 - 12:52 PM

#22

I've got a jackplate mounted Mercury L6 115 on my Montauk, and it will run over 50 with a 20" Mercury Laser II prop and 5800 RPM red line. You should be able to get more than 43 out that Yamaha 115. That is the realm of a 90 HP engine.

Over 45 MPH in a Montauk you feel like you are "flying"

Edited by Finnegan on 04/16/13 - 1:04 PM

Posted by Chichibio62 on 04/18/13 - 11:01 AM

#23

I try to raise the engine until the last hole.
then let you know.
thanks finnegan.
regards
piero