1974 Mercruiser 140 Kicker size?

[beericks]

I have a 1974 Sterncraft deep-V fiberglass 17.5 ft boat with a 140 HP 4 cylinder mercruiser motor. I would like to know what size of kicker I should purchase for both emergency and trolling. Thankyou

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

Welcome to IBoats board.

I think a 15 HP is ideal.
A 9.9 on most brands is the same motor with with a smaller carb and not as much exhaust tunning.
The main thing is the weight and the 9.9 and 15 HP are the same weight so get the 15 HP.
If he is only an inland boater so likely not running 20 miles to a fishing spot you could also use an 8 HP.
I would not go smaller than an 8 HP.

Also if he is an ocean fisherman then it needs to be a Long shaft.

I just converted mine from a 15 Hp 2 cycle to a 15 HP 4 cycle. I wanted the 20 HP made with the same block but for some reason they only sell the 20 HP with power tilt if you want the electric start.

My boat si 21 foot Aluminum and weighs 2800 pounds dry.

15 Hp is fine on mine except offshore in 6 to 8 foot swells and 30 knots of winds.
In above conditions the 15 works but if have to turn up into the wind and swell it takes too long to make the turn.

I have a High Thrust 4 blade prop 10 dia and 7 pitch.
The 4 blade large diameter prop makes a big difference in backing into the wind or swell.
Top speed wide open is 5 MPH.

I use an EZ-Steer to steer with the main motor even if only running the kicker.

 

[kmarine]

Re: 1974 Mercruiser 140 Kicker size?

I would probably consider 8 to 15 hp. You may have to look for a long shaft, it depends on what type of mounting bracket You have. I had my 20 ft boat on Lake Michigan. The long shaft kept the engine from getting dunked in rough water. Ido know some people who use a 25hp. I dont believe they run them at full throtle. How much extra weight do you want to haul arround. check with bracket mfg. they may have some type of recomendations.

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

Alright thankyou for the input. So will I need a long shaft because I will not be going in the ocean? I want to steer from my I/O and hopefully hook up a throttle control also. Which one would be more feasible for a deep-V boat used only for inland lakes?

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

If your not going in salt water with big swells then a short shaft will work fine.
In the 1st picture I loaded you will see a 5 inch spacer where I converted my 15 hp from 15 inch shaft to 20 inch.
The 15 inch short shaft worked fine in calm waters.
Inland lakes and river you will not get 8 foot swells where the motor goes completely under the water as the swell approaches and then the prop come out of the water as the swell passes under the boat.

However if your boat has a 20 transom then you will still want to get the 20 inch shaft.
If mounted like mine on a lift bracket then just measure 4 times before you drill the holes.

If your boat is like mine and in the wind the bow always turns down wind when drifting then I would still recommend the 4 blade by 10 inch by 7 pitch prop.
My 21 foot Aluminum Runabout when trolling for Salmon down stream in the river and get a snag would not back at all against a 2 knot current with the standard 3 blade by 9 ? by 10 pitch prop.
Also in the wind out on the lake fishing for Bass or trying to back into a Beach against the wind the standard prop not worth much.
Good part about the prop is you can try it first and buy it later if you decide you need it.

 

[Bondo]

Re: 1974 Mercruiser 140 Kicker size?

I have a 1974 Sterncraft deep-V fiberglass 17.5 ft boat with a 140 HP 4 cylinder mercruiser motor. I would like to know what size of kicker I should purchase for both emergency and trolling. Thankyou

Ayuh,... What makes you think you need a kicker for trolling,..??
That tiny boat has enough load now with the I/O...
That motor will gladly idle All day trolling..
And,..
With proper maintance, that little 140 will not only get you to the fishing grounds, 'n troll all day,...
It'll bring you home just as well...

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

I think I need a kicker because I was stranded once with whitecaps. The problem was that I spun a couple teeth on my distributer drive gear and only a trip to napa could cure that problem. I also have to throw out 2 five gallon buckets to slow me down enough to troll and I still don't know if that is slow enough because I am just getting set up and do not have a speed gauge yet. I fish for Bass and Walleye and have a 19 pitch prop on my boat. I am also pondering a happy troller trolling plate but a backup motor would be nice also. I am confused about part of your post Boatist. What is a "20 transom"??

 

[elkhunter338]

Re: 1974 Mercruiser 140 Kicker size?

Boatist is correct in all he said.
My 140 trolls to fast unless I am fishing for coho. I have a 15hp 2 stroke Johnson 2001 with the 4 blade prop like Boatist shows. 7 pitch solaris.
I get 5mph in the ocean wot (4500 rpms).
I know of some guys with these high thrust 9.9 that they love.
I personally was looking to put a 20hp high thrust honda on my 21 foot cheiftain (alum. starcraft cuddy cabin), because I had a 25hp kicker (7 mph) and I lost that motor, but I did not buy a honda and put my 15hp back on the boat.
I think a spare motor is a must when you can't row.

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

ElkHunter
I agree offshore for sure one should have a second motor.
I just converted my rig this year from a 1975 15 HP Johnson 2 stroke in the pictures
to a 15 HP Honda 4 stroke 20 inch shaft with electric start.
Like you I wanted the 20 HP Honda but for some reason they will not sell that motor without the power tilt.
I think it add 31 pounds to the motor and I did not want the extra weight.
So we settled for the 15 HP Honda 20 inch electric start.
I wanted the Electric start because it has a 12 amp alternator and also because often it just me and the wife these days.
I was not sure she could start our 1975 15 HP Johnson 2 storke should something happen to me.
I was shocked that even at idle speed the battery voltage is 14 volts.
It came with a 3.2 gallon plastic gas tank that I thought was a joke and told the dealer that.
I was very supprised how little fuel it uses.
I did also hook it up to the main tank so can make sure hot to run out of fuel.
My Crew loves the new motor. It is so quite offshore in the wind and sea you must listen closely to tell if it running.
Crew hated the smoke of the old motor when backing into the wind to slow our drift in the Pacific Ocean.
That what we use if for most of the time.
I love the extra battery charging to keep both batteries charged should something happen to our 1980 140 Hp OMC Stringer.
It has more power than the old 1975 15 hp Johnson that was rated at the power head.
Of course the old motor was ths same power head as 9.9 HP and this motor is the same power head as the 20.
I think the real difference between the 15 HP and 20 HP Honda is in the carb and really comes into play at the top end in extra RPMS.

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

Thanks guys!!!! Now all I need is to find a motor up here in Montana without paying an arm and a leg

 

[elkhunter338]

Re: 1974 Mercruiser 140 Kicker size?

Boatist,
How well does that 15hp honda push the boat compared to the 2 stroke.
Do you still get 5mph wot, or less or more speed at wot.
I agree a 4 stroke would be nice, I found I get alot less smoke with my 2 stroke if I run it 50:1 with non eth fuel.
I was running is about 32:1 with eth fuel.
I never looked at another kicker in enough detail to see that the 20hp only came with the power tilt.

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

ElkHunter
I am sorry to say we have not done a WOT Run yet.
After we put it on, all our trips were to the Pacific Ocean.
Best condition we had was 5 foot seas every 8 seconds with 20 knots of wind.
Since it still in the break in time I did not want to run WOT.
In the condition we were in would have not very good reading anyway.
Just turning back or backing to clear a snag I can tell you it has more low end power than my 1975 15 HP 2 stroke.
Of course at that time HP was measured at the power head and also at least 3 times Johnson said they maid changes to increase power.
I always ran 50 to one in my old motor except for some Salmon trolling where I ran 75 to 1.
I tried this a couple of times after talking to OMC Factory reps about a problem I was having with plugs fouling.
They said could run even 100 to one at trolling speeds. I tried it and it made no difference in fouling.
Fix the fouling problem by running OMC Engine Tuner and moving to a plug 2 ranges hotter.

I wanted the 20 HP so checked both Honda and Yamaha and both only come with power tilt.
I wanted the electric start so Wife could start it and also wanted the 12 amp alternator.
I looked for 3 years thinking they would some day sell the 20 electric start without power tilt.
I ask it they could remove power tilt from the electric start or add electric start and bigger alternator to the manual 20 but they all said no.

Finally last year I found 15 HP electric start 20 inch for a great price.
It is actually a 2006 engine but brand new in the box.
Then I ask if there were any changes in the newer motor and he said NO.
I verified that with the best honda dealer here in Sacramento.
Had to drive up to Reno, NV to pick it up but we were going up to Cabela's anyway so no big deal.
I do not like the silver color but love the motor.

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

Should I go for a 4 stroke (my I/O is a 4 stroke) or 2 stroke? My idea was to tee off the gas line and run it to the kicker. Is that feasible? I dont have a lot of money for this project and just want something I can control from the captains seat (steering, shifting, and acceleration) But if that does run into bucko bucks I would settle for something I can control from the back of the boat. I have around $500 total

 

[elkhunter338]

Re: 1974 Mercruiser 140 Kicker size?

beerricks,
I am sure for $500 you are going to be stuck with an old 2-stroke.
Which is ok, you just need a spare tank, I have a 6 gallon one and it works fine.
If you ocean fish you need a longshaft.

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

I agree, even used for a good late model 15HP 2 storke Johnson I would expect to pay around $700.

Early models like my 1975 are a little cheaper.
OMC Johnson or Evinrude 15 HP had several changes over the years.
They changed the head to a new design to help prevent plug Fouling.
They changed the Spark system 3 or 4 times and each time too a hotter spark.
They added a water pump indictor or Pee Stream.
They changed the fule pump.
They did more Exhaust tunning for more top end power.
They changed tiller handle design.
If I was buying a used one I would want one 1991 or later.
One other thing is the first 15 HP were rated at the power head where the later motors were rated at the prop shaft.
This means about 10 percent more power.

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

I found a 1976 Johnson 35 HP. Do you think it is smart to buy this motor for a kicker?

 

[fishrdan]

Re: 1974 Mercruiser 140 Kicker size?

I have a Troll-a-matic trolling plate on my 140HP mercruiser and it dials the engine down to 1.5-2MPH, this is with a 15x19P prop, with a 14x19 prop it crawls. I like the 15x19 prop better on my 18' Crestliner though.

I'm doing something a bit different and running a 70# transom mount trolling motor, to long line troll with. I also have a 100 amp alternator so when the TM batteries are getting low I can start the main and troll/charge the batteries back up. The TM is a Minnkota Vector (digital) and the batteries last a long time. A couple weeks ago I trolled 10 miles on the TM, then fired up the main and trolled for 2-3 hours charging the TM batteries back up, then swapped back to using the TM. I did this a couple times and never ran out of TM battery power. The TM doesn't have enough guts to troll up swell in 2-3' stuff, but going down hill isn't a problem. And, If I got stuck it would be enough to get me back,,, as long as I didn't have to fight against big waves. This probably isn't the perfect solution for most, but I like it as it's the only way to troll dead quite in this big of a boat.

Heading out in a couple hours to try it out again...

 

[Boatist]

Re: 1974 Mercruiser 140 Kicker size?

Beericks
I Would not go with a very old 35.
First the motor is very heavy and a 1976 does not have of the improvrments of current motors.
It is too heavy for any type of lift bracket.
Yes it would push your boat back in but I would not be happy with that heavy of a motor.

 

[beericks]

Re: 1974 Mercruiser 140 Kicker size?

I found a stationary bracket from panther that is rated up to 40 hp. You dont think it will work? Here is the craigslist ad: http://sd.craigslist.org/boa/2111533905.html Its within my price range but have to spend 10 hours driving and $150 in gas. If I went with the stationary bracket cant I just tilt the motor up and out of the way or will that put too much stress on the bracket when I am cruising?