Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Montauk 17 ETEC 90 mounting

Posted by action on 05/18/15 - 5:36 PM
#1

I'm looking for some comments on ETEC mounting height. I got a 1988 Montauk 17 this year. The ETEC 90 has a Viper with 15" pitch. It is mounted with 1 hole showing above the top mounting bolts.
I get about 35MPH at about 5300RPM WOT on the ICON guages.
It appears the recommended mounting here is 3 holes showing above the bolt.
It seems to run pretty good as / is (there were 5 adults on board Sunday and it got right up on plane and ran great) and I was wondering if it is worth messing with. There is something between the motor and transom that looks like 4200 or something similar.
I don't know that I'll ever run more than about 4000 RPM anyhow.

Posted by chiburis4 on 05/18/15 - 6:07 PM
#2

Hi action, I have a 1990 Newport that when I bought it, the 90 ETEC was mounted all of the way down and it was a real dog. I raised it all of the way up in the mounting holes and what a difference it made. Could not be happier.
Good luck.
Steve

Posted by Phil T on 05/18/15 - 6:47 PM
#3

The motor needs to be installed so that with the proper propeller, at WOT, it reaches the right RPM. Regardless of how fast you go, you want the motor installed and propped correctly.

Too low or having a prop that has too much pitch will lug the motor.
Too high or too small a pitched prop will cause the motor to exceed max RPM.

I see you have a 22 gallon fuel tank under the RPS and a second 8 is gallon in the stern. What is your typical load in terms of gear, fuel passengers and ice?

Alone and empty, the boat should reach 41-43 at WOT and not 35. These speeds are by GPS.

We know from member testing that for a Montauk, E-TEC's like to be mounted as high as possible. 3 holes up at a minimum. A good performing prop is a Stiletto 13 1/4 x 15 prop. Another suggestion is the BRP Viper but the engine only 2 holes up.

Here is one of the dozen or so threads for reference:

http://www.whalercentral.com/forum/vi...d_id=17073

If you will have a heavy load most of the time, you should consider dropping down in pitch by 2" to ensure you hit the WOT range.

Edited by Phil T on 05/18/15 - 6:57 PM

Posted by action on 05/18/15 - 6:53 PM
#4

The 22 is the only tank typically on the boat. The other one was a backup during the test of the 22.
I usually would have 3 people (about 600 lbs.) and some tackle and a cooler (maybe another 100 lbs total).
The bottom paint is pretty ratty with blotches missing (I bought it like that and trailer the boat). I hope to get it repainted next month.

Posted by Phil T on 05/18/15 - 6:58 PM
#5

Raise the motor and try the 12" Viper or Stiletto pitch referenced above with that load.

Posted by action on 05/18/15 - 7:01 PM
#6

In case I get energetic, can someone tell me the correct torque for the mounting bolts?

Posted by Tom Hemphill on 05/19/15 - 4:06 AM
#7

The installation manual specifies 40 ft. lbs.

Posted by action on 05/20/15 - 2:47 PM
#8

Since iI have 2 15" pitch Viper's, I will probably not try a Stiletto.
So what do you guys think? 2 or 3 holes up?
Most times there is 2 adults aboard and 20 gallons of fuel, but last week there was 5 and it ran great and got right up on plane.

Posted by crbenny on 05/21/15 - 6:04 AM
#9

IMO, you've got to come up 1 hole. I carry less fuel and I carry it further forward and even when mounted all the way up, I won't blow out with the Viper 17".

I ran 2 holes up for a year. Moved all the up last year and everything improved, although I don't think the improvement was significant. My low speed (1200 rpm) vibration got worse although I can't surmise why it would matter. I'm going back down to 2 holes up to see what the vibration does. I'll probably leave it there but we'll see.

Chris

Posted by action on 05/22/15 - 11:41 AM
#10

I got down by the boat today and looking at the motor it appears at one time it was 3 holes up. There was a wear mark the size of a washer on the bottom hole.
The motor was installed by the previous owner (according to the receipt) in July of 2012. The receipt also had a Viper 17" on it but the boat has a 15".
It ran great today out fishing. I may just leave it be for now.