10hp much faster than 6hp ?

67Johnson6HP · Nov 11, 2007

Thinking about buying a 56 Johnson 10hp. Do you think I would notice much more power than my 67 Johnson 6hp? The boat is a 14' Jon. Since joining this forum and reading a lot of posts, I've become attached - so to speak - to old outboards. My 6hp pushes the boat fine for how it's used. Just got the bug for an older motor. Thanks.

tashasdaddy · Nov 11, 2007

Re: 10hp much faster than 6hp ?

40 % increase in power, also a heavier motor. i believe there is enough difference you will notice the power.

jbjennings · Nov 11, 2007

Re: 10hp much faster than 6hp ?

You made a good choice, I think. So good, that I also just bought one of the same yr. and hp. myself. I, too, have been bitten by the old OMC bug. If you like your six you will love the ten! The main problem with them is that you won't have enough time to run 'em often enough. The 10hp will most definitely outrun the 6 hp but most importantly will plane you and a friend easily and carry plenty of goodies like an old model 11 remington shotgun or model 12 winchester and a pile of mallards, and your trusty labrador retriever.

Sorry for the ramble--duck season just opened here and I've been daydreaming,
JBJ
BTW, feel free to post a pic of your new 10.

F_R · Nov 11, 2007

Re: 10hp much faster than 6hp ?

Sure, you will notice a large increase in power...normally. Really depends on the particular boat. I learned to ski behind a Johnson 10on a Chris-Craft kit boat. But that was 50 or 60 pounds ago too.

steelespike · Nov 11, 2007

Re: 10hp much faster than 6hp ?

The 56 10 hp was rated for over 20 mph stock under ideal conditions.Your
6 would be in the 15 mph.range. Under ideal conditions the 10 could plane with 3 adults at 150 lbs each.The 6 might plane 2 adults under ideal conditions.That 14 jon should really scoot with a 10.

Silvertip · Nov 11, 2007

Re: 10hp much faster than 6hp ?

I used one of those on a 16 foot pontoon years ago and it pushed that boat just fine. It also pushed a 14 foot tin boat I had at a scary pace.

samo_ott · Nov 11, 2007

Re: 10hp much faster than 6hp ?

TD, where's your math, that's a 66.6% increase in power!

I also used a 10hp on my 16' pontoon boat and it moved it nicely. I have also run my 5.5 and 10 on the same 14' aluminum boat and it's night and day difference... the 10 really moves the boat, the 5.5 putters along nicely... (an 18 was scary fast!) By all means get/use a 10... I run a '58 10hp and it's sweet (once I find out why it's going through LU's)... the '56 had the older heavier LU though (same as the 18) and is much more bullet proof.

Skiing behind a 10hp? Wow... not sure on that one! I started behind a 25!

F_R · Nov 12, 2007

Re: 10hp much faster than 6hp ?

The 10 belonged to my cousin. I had a 12hp Gale Buccaneer on my boat and couldn't get up on the skis. But once I learned how to do it with my cousin's boat I could the ski behind the 12 also. Kind of embarrasing, the 10 would outrun my 12. But the 10 was on a better boat. But I fixed that...got a 35.

K.B · Nov 12, 2007

Re: 10hp much faster than 6hp ?

Same here.
14 ft. flat bottom w/ a 6 Johnson. Sold the motor and now have a '56 10 hp. Great motor and noticed a good bit of difference in the ride. Definitely a good combination.

Texasmark · Nov 12, 2007

Re: 10hp much faster than 6hp ?

I had a Johnny 5.5 of about '56 origin and never could get it to plane out on the little boats I rented.....wooden and reasonably heavy. Had a 7.5 Merc of about '74 origin and it planed a loaded 12' alum Lowe Lake John (wide high sided john) at a very nice clip; great hole and all. Always wondered what a 9.9 would do on it. We used to use 10 hp on 14' rent boats as a kid and had a hard time planing out, but the boats were heavy as was dad, and we had a lot of gear aboard.

Mark

samo_ott · Nov 12, 2007

Re: 10hp much faster than 6hp ?

In '56 and '57 the 15/18's were only weighed about 5 lbs more than the 10's... Great power to weight ratio, if your boat can take the power, I'd highly recommend going to an 18. Of course the electric starts then added a few more pounds in...

In '58 they shrunk the LU down and then the 10hp was about 10 pounds lighter... But I have always had problems with the smaller LU's on my '58's

tashasdaddy · Nov 12, 2007

Re: 10hp much faster than 6hp ?

true samo, used my head, instead of calculator. thats ways a long time ago.

wbeaton · Nov 12, 2007

Re: 10hp much faster than 6hp ?

You can't go wrong with a 10 hp. The difference will be night and day. My 10 hp's all push my 12.3' tin boat around 21 mph.

Samo, the lower unit problems are quite well known on the 1958. They switched to the 5.5-7.5 hp lower unit casing to shave weight and increase speed, but it was too light for the torque output of the motor. Now I'm not sure of the exact chain of events, but I believe the bushing at the pinion may deform from the torque causing the driveshaft and pinion to wobble. Or that the driveshaft or pinion was undersized. Either way the problem stems from around the pinion gear.

10hp much faster than 6hp ?

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