help on motor choice

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

arkansasnative

Well-known member
Joined
Dec 6, 2009
Messages
339
Reaction score
0
Location
Jonesboro, Arkansas
im in the process of restoring my 1967 model 1432 monark and ive come to the point of finding an engine. since my boat is so old i dont have an info plate or even a stamped serial number on the transom. the only reason i call it a monark is it has the same body shape and lines ive seen in pictures. the boats ribs (i cant remember the technical term right now) dont go up the sides of the boat and theres no framing that braces the transom so im confused as to how big of a motor i can run safely. im looking at 10hp motors right now... but i dont want to over do it. here's a couple of pictures of my transom for reference...

231.jpg

230.jpg
 
I think you would do fine with a 10hp motor so long as your not running in a river with a strong current. My son has a Lowe 14 X 36L and had a 9.9 1965 Sears motor that handles it nicely with power to spare.
He has since put on a 72 Evenrude 15hp on it and it's almost too much motor.
His boat is mfg rated for 15Hp so yours should be close?

Before Iowa instituted a no wake law on lakes under 1,000 acres, we were restricted to 6hp.
I saw everything from 10ft-18ft boats running 6hp and while they were not fast they got us to where the fish were.

I would be most concerned with getting a motor that was too heavy.
You don't want the transom dragging. look up new boats of that aproximate size and chech the total weight capacity ratings.
Try to stay around or under that weight all up and you should do fine.
 
yea ive been looking at newer ones but alot of them have more bracing... the motor im looking at right now is a 1950 johnson qd-11 (10hp). a newer motor would be nice but if i can get a good older one for cheaper then im in! and the coolness factor is just icing on the cake!
 
Well with the 9.9 on that boat and 3 of us in the boat it was probably going 8- 10mph or so.
Bailey probably goes 220, his son 180 and I weigh 175 so we were running at maximum reccomended capacity and doing that speed,impressed me. He thought he needed more motor to run on the Des Moines River, between Red Rock and Des Moines? I still think the 9.9 would have done it well.
Like I said the 9.9 is a 1965 and the Evenrude Speed Twin 15 is a 1972.
So a good solid motor is that regardless of it's age. And it's kind of fun to run an antique.
If he decides to stick with the 15, I may talk him out of the 9.9.
 
I would agree. A 9.9 would be fine for your boat. It would move it just fine. I had a 1236 with a 9.9 gamefisher and the boat was great. I would get a 2 stroke they are lighter so you wont have the extra weight in your boat. Good luck.
 
Outdoorsman said:
Here is a link to the Coast Guard home boat builders guides. It is kinda of technical but it has the formula for calculating max HP for any boat...

https://files.dnr.state.mn.us/education_safety/safety/boatwater/backyardboatbuilders.pdf

I hope this helps....


if i use that formula or the one on the motors forum page it is saying i shouldnt be using more than a 6-7.5hp motor. that really doesnt seem like its gonna get my 14 footer up on plane very easily...

i have also tossed around the idea of adding bracing or a knee brace to the transom to stiffen everything up but im not quite sure how id go about that. the ribs are steel so i imagine i could run a piece of tube metal from the rib/brace on the back of the rear bench to the transom.
 
I'm sure the ribs aluminum. If you bolt something in use stainless steel hardware.
 
arkansasnative said:
if i use that formula or the one on the motors forum page it is saying i shouldnt be using more than a 6-7.5hp motor. that really doesnt seem like its gonna get my 14 footer up on plane very easily...

I'm not sure the 9.9 would get your 14' on a plane either.
 
I had a 9.9 4 stroke on a 12/32, I think you could go with a 15 on the 14 footer easily. I would add a transom brace though, no matter what I put on the back.
 
im pretty sure ill end up bracing it no matter what... thats always been in the plans. the ribs have surface rust on them where theyre missing paint. like i said this boat is old so steel ribs wouldnt really surprise me.
 
well it turned out the motor i was looking at was a long shaft so i passed on it but i did find 2 others... im pretty sure ill be choosing my final motor between these:

1. 1963 evinrude sporttwin 10hp: good cosmetically some small scratches, had a full tune up and new prop in 2008 and hasnt been used since.

2. 1972 johnson 50th anniversary 10hp: slightly more compact, some scratches but decent overall, recent rebuilt carb and new water pump.

i really cant decide which would be better but i like both of these... anyone have any opinions on either? thanks guys!
 
i highly recommend not getting an old one- they use pressure tanks and aren't as reliable out there. buy a more expensive newer one and you won't have to shell out hundreds to get an old one running.
 
Neither one of those motors uses a pressure tank, IIRC, so you should be good to go. I too would stay away from one needing a pressure tank, but not due to reliability. They are plenty reliable, in many cases, moreso than motors of now. Instead, because the pressure tanks are becoming harder and harder to find, and most all of the ones in existence are worn out, driving the price of good ones way up. However, a fuel pump can be added onto the early pressure tank motors.
 
bassboy if you were to have to make the decision between the two which would you choose and why? here are the links...

https://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150442903795&viewitem=&sspagename=STRK:MEWAX:IT#ht_500wt_1182

https://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320532858076&viewitem=&sspagename=STRK:MEWAX:IT#ht_600wt_1165
 
I'd choose the 1963 10, just as I'm not real crazy about the 9.5s (your 1972 is a 9.5, not a 10). While they aren't a bad motor per se, they aren't the easiest to work on (to make them lower profile, they jammed the powerhead down the midsection, giving you tight quarters), and and I don't believe they share as many parts as the 10 probably would.
 
gregk9 said:
Jim-Iowa said:
Before Iowa instituted a no wake law on lakes under 1,000 acres,


Huh?? :shock: For real????

Yeah it's true on State owned and many County lakes. The Exceptions are the Great Lakes area of NW Iowa(Okeboji, Spirit Lake Etc) Private Lakes and Federal impoundments.

You can operate any motor, but no wakes. There are also many lakes under 100 acres where Electric only is the law.
The Lake I grew up on Rock Creek Lake is 640 acres and was limited to 6 hp until they changed it to no wake.

I have a friend who was fishing on that lake in a 12 ft Jonboat and some joker cranked on his 75 hp and the wake swamped him and his wife in 20 ft of water. This was back in the 70's and his boat went straight to the bottom.
 

Latest posts

Top