MONTAUK: Johnson 70-HP Four-stroke - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  MONTAUK: Johnson 70-HP Four-stroke

search | FAQ | profile | register | author help

Author Topic:   MONTAUK: Johnson 70-HP Four-stroke

floatinghat posted 09-18-2007 11:55 AM ET (US)
I just [purchased a Johnson 70-HP four-stroke motor, a rebadged Suzuki,] for my [1977 MONTAUK 17]. I have some questions as to what I need to optimize my boat. I am a complete boating nooob, yet willing and excited to learn. From reading multiple threads I believe this is a fantastic motor and will serve us well as long a I have the boat. I will upgrade in the future to a larger Boston Whaler. My desire is to get this boat in the water soon, as I purchased it in July and haven’t been able to use it. The wisdom of the multiple opinions leaves me with a few remaining questions, I want to get it right (or very close) the first time.
It sounds like my old Morse controls will work. The old motor was a 1980 Evinrude 115
Can I just install a dash switch for the tilt?
Should I invest in a jack plate? How high should I mount it the engine? I believe, I have the blind holes; it appears there are only two bolts through the transom.
What propeller? Most of the use will be in the Puget Sound fishing, crabbing with the family, total family weight 500 to 600-lbs including gear. Might pull the kids behind on a tube on occasion.
Gauges, I have none. [Seeks] recommendations. I was looking at these; the fuel would not be hooked up.
[Extrarodinarily long link to web auction deleted. Please link to images directly, not to web pages containind links to images--jimh.]
I plan on re-wiring the boat this winter and potentially painting and gel coating the interior. Not what I would consider a [unclear--perhaps meant "restoration"] as I might not go 100% original. I like my stuff to be nice and classic looking, with great functionality. Anything else I should get consider must do?
Tohsgib posted 09-18-2007 12:08 PM ET (US)
You "should" be able to use the controls and yes a dash mounted trim & keyswitch is fine. My 70 I would set the trim and forget it for the day. Only problem I see is warning buzzer and new keyswitch. Might be cheaper to find a set of newer OMC/BRP controls($225ish) with keyswitch/buzzer/trim button built in than paying a guy $70 an hour to rig it up with your stuff. I would ONLY use a systems check tach & gauge which can be had on E-Bay or at store by me for about $69. Wiring harness might come with engine or I can get them for the same price as the gauge. Your prop will work if a 13.25x17. A 19" will not be good which many 115's ran. Redline is 5800 and a 17" will get you there with light load. I ran a 18" and maxed at 5650 or so full tilt boogie. If you are in blind holes I would get a jack plate and jack her up pretty high. Page 67 in cetacea shows my old Evinzuki on my montauk towards the bottom. I got about 10mpg at cruise and hit 39+ WOT but most are getting about 36-38mph WOT. Must have been the Evinrude part of the engine on mine ;)
I do not think they come with any fluids so double check all that. Oil filter is at local autoparts store, just get one for a 1990 Suzuki Samurai or any other year you wish. After the first season put synthetic in it if you want but at 50 hours a season, might not be worth it...then again it is only an extra $15 or so.
Tohsgib posted 09-18-2007 12:12 PM ET (US)
No you can NOt use that gauge you need [an OMC SystemCheck gauge or SystemCheck Tachometer].
I have another Surplus place near me that has all the stuff you need for 1/2 of what the stealership gets.
floatinghat posted 09-18-2007 02:46 PM ET (US)
Is this the proper cable?
[Apparently quoting a description from somewhere]--OMC modular wiring system instrument cable, Johnson and Evinrude. 28', Cable is complete ready to use, comes with installation instructions. The instrument cable in this kit is compatible with the 1996 and newer OMC modular wiring system.[End of apparent quotation.]
Tohsgib posted 09-18-2007 03:07 PM ET (US)
Yes but 28' is pretty long but then again just coil it up under the console. I think mine was 20'.
an86carrera posted 09-18-2007 04:38 PM ET (US)
I have the cable and the System Check guage. I'll check the length (I think 20') and repost tonight. The gauge is white face and white bezel. Also have a binnacle mount shift throttle with cables it works but it is not pretty.
jimh posted 09-18-2007 08:43 PM ET (US)
The 70-HP Johnson or its twin Suzuki DF70 motor has been used to re-power the Boston Whaler MONTAUK by many owners. You should be able to get good propeller recommendations from these owners.
If you are not sure of exactly what you need, buying surplus items on an on-line auction web site can be more expensive than just getting an OEM part from a dealer. By the time you buy two or three of the wrong things, you won't have saved much money.
Generally the MORSE controls can be adapted to most engines by fitting the proper cable ends onto universal cables, or by buying the specific cables for a particular motor's style of connection.
A trim and tilt switch is quite simple electrically and for someone who understands the basics of electricity and electrical wiring it is a trivial matter to substitute a non-OEM switch in a panel mounting at the helm for use in controlling the electrical trim system.
While not at all related to the PERFORMANCE of your boat, the most important aspect of a restoration of a classic boat like a Whaler is to have the original components or to replace any missing original components with suitable replacements.
floatinghat posted 09-19-2007 08:29 AM ET (US)
Len
Anything additional on the length of that cable? Any additional info on the controls Key, kill, buzzer I assume binnacle?
an86carrera posted 09-19-2007 09:35 AM ET (US)
Yes the cable is 20' there is a key and buzzer system too. There throttle and shift cable length should be good for your application also.
floatinghat posted 09-19-2007 11:26 PM ET (US)
As I look for a prop either a 13.25x17 or 18 would it do any harm to use a 13x19? I understand I wouldn't be able to pull max revs but I doubt I will have the time to get thru a good break in.
Tohsgib posted 09-20-2007 10:15 AM ET (US)
Yeah...I ran a 19 until I got my 18 I think it redlined at about 54-5500 and was pretty good but the 17 or 18 is better. Come winter you can just have your prop repitched.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: MONTAUK: Johnson 70-HP Four-stroke
floatinghat	posted 09-18-2007 11:55 AM ET (US) I just [purchased a Johnson 70-HP four-stroke motor, a rebadged Suzuki,] for my [1977 MONTAUK 17]. I have some questions as to what I need to optimize my boat. I am a complete boating nooob, yet willing and excited to learn. From reading multiple threads I believe this is a fantastic motor and will serve us well as long a I have the boat. I will upgrade in the future to a larger Boston Whaler. My desire is to get this boat in the water soon, as I purchased it in July and haven’t been able to use it. The wisdom of the multiple opinions leaves me with a few remaining questions, I want to get it right (or very close) the first time. It sounds like my old Morse controls will work. The old motor was a 1980 Evinrude 115 Can I just install a dash switch for the tilt? Should I invest in a jack plate? How high should I mount it the engine? I believe, I have the blind holes; it appears there are only two bolts through the transom. What propeller? Most of the use will be in the Puget Sound fishing, crabbing with the family, total family weight 500 to 600-lbs including gear. Might pull the kids behind on a tube on occasion. Gauges, I have none. [Seeks] recommendations. I was looking at these; the fuel would not be hooked up. [Extrarodinarily long link to web auction deleted. Please link to images directly, not to web pages containind links to images--jimh.] I plan on re-wiring the boat this winter and potentially painting and gel coating the interior. Not what I would consider a [unclear--perhaps meant "restoration"] as I might not go 100% original. I like my stuff to be nice and classic looking, with great functionality. Anything else I should get consider must do?
Tohsgib	posted 09-18-2007 12:08 PM ET (US) You "should" be able to use the controls and yes a dash mounted trim & keyswitch is fine. My 70 I would set the trim and forget it for the day. Only problem I see is warning buzzer and new keyswitch. Might be cheaper to find a set of newer OMC/BRP controls($225ish) with keyswitch/buzzer/trim button built in than paying a guy $70 an hour to rig it up with your stuff. I would ONLY use a systems check tach & gauge which can be had on E-Bay or at store by me for about $69. Wiring harness might come with engine or I can get them for the same price as the gauge. Your prop will work if a 13.25x17. A 19" will not be good which many 115's ran. Redline is 5800 and a 17" will get you there with light load. I ran a 18" and maxed at 5650 or so full tilt boogie. If you are in blind holes I would get a jack plate and jack her up pretty high. Page 67 in cetacea shows my old Evinzuki on my montauk towards the bottom. I got about 10mpg at cruise and hit 39+ WOT but most are getting about 36-38mph WOT. Must have been the Evinrude part of the engine on mine ;) I do not think they come with any fluids so double check all that. Oil filter is at local autoparts store, just get one for a 1990 Suzuki Samurai or any other year you wish. After the first season put synthetic in it if you want but at 50 hours a season, might not be worth it...then again it is only an extra $15 or so.
Tohsgib	posted 09-18-2007 12:12 PM ET (US) No you can NOt use that gauge you need [an OMC SystemCheck gauge or SystemCheck Tachometer]. I have another Surplus place near me that has all the stuff you need for 1/2 of what the stealership gets.
floatinghat	posted 09-18-2007 02:46 PM ET (US) Is this the proper cable? [Apparently quoting a description from somewhere]--OMC modular wiring system instrument cable, Johnson and Evinrude. 28', Cable is complete ready to use, comes with installation instructions. The instrument cable in this kit is compatible with the 1996 and newer OMC modular wiring system.[End of apparent quotation.]
Tohsgib	posted 09-18-2007 03:07 PM ET (US) Yes but 28' is pretty long but then again just coil it up under the console. I think mine was 20'.
an86carrera	posted 09-18-2007 04:38 PM ET (US) I have the cable and the System Check guage. I'll check the length (I think 20') and repost tonight. The gauge is white face and white bezel. Also have a binnacle mount shift throttle with cables it works but it is not pretty.
jimh	posted 09-18-2007 08:43 PM ET (US) The 70-HP Johnson or its twin Suzuki DF70 motor has been used to re-power the Boston Whaler MONTAUK by many owners. You should be able to get good propeller recommendations from these owners. If you are not sure of exactly what you need, buying surplus items on an on-line auction web site can be more expensive than just getting an OEM part from a dealer. By the time you buy two or three of the wrong things, you won't have saved much money. Generally the MORSE controls can be adapted to most engines by fitting the proper cable ends onto universal cables, or by buying the specific cables for a particular motor's style of connection. A trim and tilt switch is quite simple electrically and for someone who understands the basics of electricity and electrical wiring it is a trivial matter to substitute a non-OEM switch in a panel mounting at the helm for use in controlling the electrical trim system. While not at all related to the PERFORMANCE of your boat, the most important aspect of a restoration of a classic boat like a Whaler is to have the original components or to replace any missing original components with suitable replacements.
floatinghat	posted 09-19-2007 08:29 AM ET (US) Len Anything additional on the length of that cable? Any additional info on the controls Key, kill, buzzer I assume binnacle?
an86carrera	posted 09-19-2007 09:35 AM ET (US) Yes the cable is 20' there is a key and buzzer system too. There throttle and shift cable length should be good for your application also.
floatinghat	posted 09-19-2007 11:26 PM ET (US) As I look for a prop either a 13.25x17 or 18 would it do any harm to use a 13x19? I understand I wouldn't be able to pull max revs but I doubt I will have the time to get thru a good break in.
Tohsgib	posted 09-20-2007 10:15 AM ET (US) Yeah...I ran a 19 until I got my 18 I think it redlined at about 54-5500 and was pretty good but the 17 or 18 is better. Come winter you can just have your prop repitched.