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Author Topic:   MONTAUK 17 with Johnson 60-HP

new2whalering posted 05-22-2010 01:04 AM ET (US)
[The author's] Montauk [has] a 1997 Johnson 60-HP. The diameter and pitch [of the stainless steel propeller in use] is hard to read on the propeller, but it looks like 13 x 15 or 13 x 16. [The MONTAUK] gets up on plane quickly with just myself in the boat. [The Johnson 60-HP engine reaches] 4,800 to 5,000-RPM at wide-open throttle (WOT) with the engine trimmed up. Seems like there is more in the motor. I have a SS 13 X 19 that will fit.
What should the RPM be at WOT?
What should I expect from [a change to a] 13 x 19 propeller [from the current 13 x 15 or 13 x 16 propeller]? I can't really afford a more powerful or newer motor. I would like to get the best performance that I can out this motor.
jimh posted 05-22-2010 09:29 AM ET (US)
The recommended maximum engine speed at wide-open throttle for your Johnson 60-HP is given in the owner's manual. Typically a range of engine speed is specified. It is common that the range will be 5,000 to 6,000-RPM. I do not have information on your 1997 Johnson 60-HP, but I would assume it is in that same range. A general rule for optimum performance is to have the engine speed reach the upper half of the suggested range at maximum throttle when operating the boat with its typical load.
If you change to a propeller with 19-inch pitch from a propeller with 15-inch pitch, you will cause the engine speed at wide-open throttle to decrease significantly, probably on the order of 800 to 1,000-RPM. A general rule is that a 2-inch increase in pitch will cause a 450-RPM decrease in engine speed.
new2whalering posted 05-22-2010 09:55 AM ET (US)
I don't have the owner's manuel for my engine. Perhaps there is a source on line or I can go to the marine dealer and ask. I had no idea that a prop with more pitch would decrease it that much. I have read on this site that the ideal prop is 13.25 x 17. Would adjustments to the linkage do anything to increase rpm
Teak Oil posted 05-23-2010 11:37 PM ET (US)
I doubt you can swing the 13x19 SS prop. My Montauk with a 90 V4 came stock with a 13x19 prop. The 90 has 30 more hp and over 40 more cubic inches than your motor.
A top performing prop on a Montauk with a 3 cyl OMC is usually a stainless prop in the 13.5 x 17 range
new2whalering posted 05-24-2010 10:11 AM ET (US)
As I recall the 13 x 19 prop did come off a Johnson 90 that was my Dad's. It was lying around the garage so I thought I would try it, but I think not. I will try and locate a 13.5 x 17 or maybe a 13.75 x 17 SS and see what that will do. I didn't like the way the motor idled either so I changed the plugs to QL78YC. They were QL77YC. That seemed to help. Nothing to do with RPMs or props, just a thought that came to mind.
Tohsgib posted 05-24-2010 12:08 PM ET (US)
Check your linkage and your compression. Your engine should be doing more than 5k with a 15 or 16" prop. Your redline is 6k so you are WAY too low, a 17 will hurt even more. You may want to go through your carbs and then synch & link them. First look to make sure you are getting WOT and your compression is good.
new2whalering posted 05-24-2010 01:35 PM ET (US)
Ran it just an hour ago. Idle is good enough at around 800 rpm which I seem to recall seeing is within spec. A little vibration but that's probably just the personality of the motor. At WOT which is really as far as the lever will go I got 5100 rpm with it trimmed up. A very nice ride and while I shouldn't be greedy I just feel like there is still more in the motor. I don't know how fast I was going because I forgot the GPS. Compression is good at a balanced 115 each. I don't have another prop to try yet, but know of a source so I can probably borrow several and see. In the meantime the linkage may be where some tinkering needs to be done. I don't know how to do it but I see some thumb screws on the rods where they attach in the motor. The linkage does feel a little sloppy and what I mean is that from about 800 rpm to say 1200 I can move the throttle and there is no response. Any suggestions on likage adjustments or should I just get the mechanic to do this. Thanks for the good advices
Tohsgib posted 05-24-2010 01:42 PM ET (US)
First you need to see if it is getting full throttle. Mash the throttle down(engine not running) and see if there is any more room to move at the carbs manually, 1/4 or so is normal. Check to see if butterflies are opened up all the way. Then check to see if they opened too far and are now closing...that will impede your WOT as it went past WOT and is moving back the other way. Butterflies are your idle and WOT settings on older OMC's.
new2whalering posted 05-24-2010 01:59 PM ET (US)
Great advice. I will check it next week after return from vacation. The motor is a 1997 model.
new2whalering posted 06-06-2010 09:00 PM ET (US)
Checked linkage and there is quite a bit more than a 1/4 inch of travel to go. The black object that pushes against the roller looks like it has a 1/2" to 3/4" left to go. I didn't get to check the carb butterflies as I forgot the screwdriver to take the air housing off. It sure looks like the linkage needs adjusting and there are two thumb screws on the cables that I suspect are for this purpose. I didn't touch them.
new2whalering posted 06-15-2010 06:13 PM ET (US)
Had prop reworked. It was a 13 X 19 SS prop. Now it is more "like" a 12 1/2 x 17 I am told. Cost wasn't bad - $143.55. Installed prop and WOT rpm with engine trimmed all the way was maybe 5400 rpm. GPS showed a max speed of 29 mph. I think I've seen other posts on this forum where folks were getting low 30s in a Montauk with a 60hp. I guess the difference between 29 and low 30s isn't worth much worry over. However, I still think there just isn't something right in the linkage. I don't like it trimmed all the way up because the boat kind of porpoised in its ride.
Engine idles at 750 or 800 under load, but it seems ragged. Good spark to all three cylinders, but still ragged with vibration. Carbs were cleaned last year, but I admit to not dumping the ethanol gas before first use this year. I thought stabilizer would be sufficient. I have run 6 gallons of regular gas through. Maybe a decarb is needed to help with the idle.
I know I'm all over the place here so apologize. Guess the main question is would linkage adjustment make for any improvement in motor WOT?
masbama posted 06-16-2010 09:53 PM ET (US)
I had the same combination boat/motor. I got 32mph with a 19" prop but it lugged the engine. Stick with the prop you have. I also had big time vibration at idle.
new2whalering posted 06-16-2010 11:29 PM ET (US)
Thanks Masbama. I was beginning to think it may be the nature of the beast. I will adjust the linkage to the extent I can and leave it at that.
weekendwarrior posted 06-17-2010 08:17 AM ET (US)
I can get 30mph pretty easily with my 50hp Honda (1996 Montauk), so I would expect you can get a couple more mph if you can get the throttle open all the way.
Tohsgib posted 06-17-2010 10:00 AM ET (US)
I used to get 37 with a 48hp and no tilt. You should easily get low 40's if it runs right.
weekendwarrior posted 06-17-2010 12:07 PM ET (US)
37mph on a 17' with only 48hp? Was this by gps? Sounds a little high to me for only 48hp.
weekendwarrior posted 06-17-2010 12:14 PM ET (US)
I should add that in my experience and from reading here, 90HP typically gets you low to mid 40's on the 17' hull.
new2whalering posted 06-17-2010 03:20 PM ET (US)
Wow! 37 mph with a 48hp. Was it one or two 48s? :-)
I'm sure I can get better performance from my motor and the side benefit will be increased speed. From reading various advices on this forum I believe it is important that an outboard be able to operate in its maximum rpm range. Once I get the cables adjusted I'll let everyone know what comes of it. Thanks for the help so far.
Tohsgib posted 06-17-2010 03:22 PM ET (US)
Nuts...I was thinking 15' Whaler, not a Montauk. You should get 33+ish with a healthy 60 on a Montauk.
new2whalering posted 07-02-2010 06:46 PM ET (US)
Just to follow up on things.
The throttle was not moving all the way so as to activate W.O.T. It was being stopped by the convex lense of the Tach. I constructed a spacer block of 1 inch starboard to raise the control and this allows it to attain W.O.T. Also I confirmed this with the carburetor butterflies and the throttle roller. Anyway, the motor is now showing 5500 rpm so I'll call that good enough. Thanks for the advices.
new2whalering posted 07-14-2010 12:28 AM ET (US)
Throttle control in correct position now. WOT is 5800 and top speed was 33.5mph with two people (350lbs), 10 gallons gas and battery.

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Author	Topic: MONTAUK 17 with Johnson 60-HP
new2whalering	posted 05-22-2010 01:04 AM ET (US) [The author's] Montauk [has] a 1997 Johnson 60-HP. The diameter and pitch [of the stainless steel propeller in use] is hard to read on the propeller, but it looks like 13 x 15 or 13 x 16. [The MONTAUK] gets up on plane quickly with just myself in the boat. [The Johnson 60-HP engine reaches] 4,800 to 5,000-RPM at wide-open throttle (WOT) with the engine trimmed up. Seems like there is more in the motor. I have a SS 13 X 19 that will fit. What should the RPM be at WOT? What should I expect from [a change to a] 13 x 19 propeller [from the current 13 x 15 or 13 x 16 propeller]? I can't really afford a more powerful or newer motor. I would like to get the best performance that I can out this motor.
jimh	posted 05-22-2010 09:29 AM ET (US) The recommended maximum engine speed at wide-open throttle for your Johnson 60-HP is given in the owner's manual. Typically a range of engine speed is specified. It is common that the range will be 5,000 to 6,000-RPM. I do not have information on your 1997 Johnson 60-HP, but I would assume it is in that same range. A general rule for optimum performance is to have the engine speed reach the upper half of the suggested range at maximum throttle when operating the boat with its typical load. If you change to a propeller with 19-inch pitch from a propeller with 15-inch pitch, you will cause the engine speed at wide-open throttle to decrease significantly, probably on the order of 800 to 1,000-RPM. A general rule is that a 2-inch increase in pitch will cause a 450-RPM decrease in engine speed.
new2whalering	posted 05-22-2010 09:55 AM ET (US) I don't have the owner's manuel for my engine. Perhaps there is a source on line or I can go to the marine dealer and ask. I had no idea that a prop with more pitch would decrease it that much. I have read on this site that the ideal prop is 13.25 x 17. Would adjustments to the linkage do anything to increase rpm
Teak Oil	posted 05-23-2010 11:37 PM ET (US) I doubt you can swing the 13x19 SS prop. My Montauk with a 90 V4 came stock with a 13x19 prop. The 90 has 30 more hp and over 40 more cubic inches than your motor. A top performing prop on a Montauk with a 3 cyl OMC is usually a stainless prop in the 13.5 x 17 range
new2whalering	posted 05-24-2010 10:11 AM ET (US) As I recall the 13 x 19 prop did come off a Johnson 90 that was my Dad's. It was lying around the garage so I thought I would try it, but I think not. I will try and locate a 13.5 x 17 or maybe a 13.75 x 17 SS and see what that will do. I didn't like the way the motor idled either so I changed the plugs to QL78YC. They were QL77YC. That seemed to help. Nothing to do with RPMs or props, just a thought that came to mind.
Tohsgib	posted 05-24-2010 12:08 PM ET (US) Check your linkage and your compression. Your engine should be doing more than 5k with a 15 or 16" prop. Your redline is 6k so you are WAY too low, a 17 will hurt even more. You may want to go through your carbs and then synch & link them. First look to make sure you are getting WOT and your compression is good.
new2whalering	posted 05-24-2010 01:35 PM ET (US) Ran it just an hour ago. Idle is good enough at around 800 rpm which I seem to recall seeing is within spec. A little vibration but that's probably just the personality of the motor. At WOT which is really as far as the lever will go I got 5100 rpm with it trimmed up. A very nice ride and while I shouldn't be greedy I just feel like there is still more in the motor. I don't know how fast I was going because I forgot the GPS. Compression is good at a balanced 115 each. I don't have another prop to try yet, but know of a source so I can probably borrow several and see. In the meantime the linkage may be where some tinkering needs to be done. I don't know how to do it but I see some thumb screws on the rods where they attach in the motor. The linkage does feel a little sloppy and what I mean is that from about 800 rpm to say 1200 I can move the throttle and there is no response. Any suggestions on likage adjustments or should I just get the mechanic to do this. Thanks for the good advices
Tohsgib	posted 05-24-2010 01:42 PM ET (US) First you need to see if it is getting full throttle. Mash the throttle down(engine not running) and see if there is any more room to move at the carbs manually, 1/4 or so is normal. Check to see if butterflies are opened up all the way. Then check to see if they opened too far and are now closing...that will impede your WOT as it went past WOT and is moving back the other way. Butterflies are your idle and WOT settings on older OMC's.
new2whalering	posted 05-24-2010 01:59 PM ET (US) Great advice. I will check it next week after return from vacation. The motor is a 1997 model.
new2whalering	posted 06-06-2010 09:00 PM ET (US) Checked linkage and there is quite a bit more than a 1/4 inch of travel to go. The black object that pushes against the roller looks like it has a 1/2" to 3/4" left to go. I didn't get to check the carb butterflies as I forgot the screwdriver to take the air housing off. It sure looks like the linkage needs adjusting and there are two thumb screws on the cables that I suspect are for this purpose. I didn't touch them.
new2whalering	posted 06-15-2010 06:13 PM ET (US) Had prop reworked. It was a 13 X 19 SS prop. Now it is more "like" a 12 1/2 x 17 I am told. Cost wasn't bad - $143.55. Installed prop and WOT rpm with engine trimmed all the way was maybe 5400 rpm. GPS showed a max speed of 29 mph. I think I've seen other posts on this forum where folks were getting low 30s in a Montauk with a 60hp. I guess the difference between 29 and low 30s isn't worth much worry over. However, I still think there just isn't something right in the linkage. I don't like it trimmed all the way up because the boat kind of porpoised in its ride. Engine idles at 750 or 800 under load, but it seems ragged. Good spark to all three cylinders, but still ragged with vibration. Carbs were cleaned last year, but I admit to not dumping the ethanol gas before first use this year. I thought stabilizer would be sufficient. I have run 6 gallons of regular gas through. Maybe a decarb is needed to help with the idle. I know I'm all over the place here so apologize. Guess the main question is would linkage adjustment make for any improvement in motor WOT?
masbama	posted 06-16-2010 09:53 PM ET (US) I had the same combination boat/motor. I got 32mph with a 19" prop but it lugged the engine. Stick with the prop you have. I also had big time vibration at idle.
new2whalering	posted 06-16-2010 11:29 PM ET (US) Thanks Masbama. I was beginning to think it may be the nature of the beast. I will adjust the linkage to the extent I can and leave it at that.
weekendwarrior	posted 06-17-2010 08:17 AM ET (US) I can get 30mph pretty easily with my 50hp Honda (1996 Montauk), so I would expect you can get a couple more mph if you can get the throttle open all the way.
Tohsgib	posted 06-17-2010 10:00 AM ET (US) I used to get 37 with a 48hp and no tilt. You should easily get low 40's if it runs right.
weekendwarrior	posted 06-17-2010 12:07 PM ET (US) 37mph on a 17' with only 48hp? Was this by gps? Sounds a little high to me for only 48hp.
weekendwarrior	posted 06-17-2010 12:14 PM ET (US) I should add that in my experience and from reading here, 90HP typically gets you low to mid 40's on the 17' hull.
new2whalering	posted 06-17-2010 03:20 PM ET (US) Wow! 37 mph with a 48hp. Was it one or two 48s? :-) I'm sure I can get better performance from my motor and the side benefit will be increased speed. From reading various advices on this forum I believe it is important that an outboard be able to operate in its maximum rpm range. Once I get the cables adjusted I'll let everyone know what comes of it. Thanks for the help so far.
Tohsgib	posted 06-17-2010 03:22 PM ET (US) Nuts...I was thinking 15' Whaler, not a Montauk. You should get 33+ish with a healthy 60 on a Montauk.
new2whalering	posted 07-02-2010 06:46 PM ET (US) Just to follow up on things. The throttle was not moving all the way so as to activate W.O.T. It was being stopped by the convex lense of the Tach. I constructed a spacer block of 1 inch starboard to raise the control and this allows it to attain W.O.T. Also I confirmed this with the carburetor butterflies and the throttle roller. Anyway, the motor is now showing 5500 rpm so I'll call that good enough. Thanks for the advices.
new2whalering	posted 07-14-2010 12:28 AM ET (US) Throttle control in correct position now. WOT is 5800 and top speed was 33.5mph with two people (350lbs), 10 gallons gas and battery.