8hp or 6hp

[bozza_boatie]

My 4hp on my old 12ft tinnie recently died.<br />The maximum Hp is 6. Would it be safe for me (considering that the 6 and 8hp engines are the same size) fit an 8hp instead of the 6?<br /><br />Any suggestions would be much appreciated? <br /><br />Thank you

 

[JB]

Re: 8hp or 6hp

It wouldn't be a problem if you never opened her up all the way, Bozza, but I don't think the 8 would give you any noticable advantage.<br /><br />If I already had the 8 or could get it easily and the 6 was hard/expensive to get I would probably use the 8 and watch out for stress damage to the boat.<br /><br />All other things being equal I would stay with 6.<br /><br />Good luck.

 

[bozza_boatie]

Re: 8hp or 6hp

Whats the difference beetween a 6 and an 8? The propellor spins faster? Big deal! I dont care what you guys think im fitting the 8. More speed! Better acceleration! Less work! and most importentrly Less fuel!

 

[DJ]

Re: 8hp or 6hp

Then why did you ask?

 

[P.V.]

Re: 8hp or 6hp

Well, let's consider this... A 6 and 8 hp Merc or Johnson 2 stroke are two cylinder same "family" motors, weigh the same, slightly bigger carb on the 8hp. Four stroke, 6 hps are single cylinders while the 8hps are two cylinders, different weights... Todays motors are rated at "true" propshaft horsepower while many years ago they were rated at the crankshaft!

 

[bozza_boatie]

Re: 8hp or 6hp

thank you PV

 

[cobra 3.0]

Re: 8hp or 6hp

The 8 will get you quite a bit more speed as it will plane your boat easily(I had a 7.5 merc 1970's and it could plane a 13 1/2 foot tinny with 2 people...not with 3)...not sure if a 6 can plane it... because on larger tinnys, the 6 won't.<br /><br />If you had a pic of the boat it would help. Most small 12 footers vary in rating from 6 to 10 hp. (Some larger 12 footers take more.) Is your hp rating by the manufacturer of your boat just a little conservative?...hard to say.<br /><br />Certainly the weight factor of the motor is important. If you do go 8, try to find a light motor.

 

[kk4df]

Re: 8hp or 6hp

I have an 8HP Mariner, 1985, on a 14 ft aluminum modified V-hull. After doing a little carb work, the motor moves the boat along quite nicely, getting up to a decent plane, clocking at 13.8 MPH by GPS. I don't believe a 6HP would have been enough in my case. Of course a 15HP would really be nice!

 

[CTD]

Re: 8hp or 6hp

I used to have a narrow 12 aluminum boat, I put a 10hp Johnson on it and it would fly but when I went to turn it would oversteer and almost throw me out of the boat. I wouldn't loan that boat to anyone but I used it for years.

 

[Bradster941]

Re: 8hp or 6hp

Bozza,<br /><br />is that a typo?<br /><br />(Bozzo)?

 

[02'Crownline]

Re: 8hp or 6hp

yea i used to have a 12 foot fiberglass green boat from the early 70's that i used to mess around in with a 1978 20 hp merc on it. (the boats max hp was recommended at 20hp...i dont know what they were thinking when they made the boat?!?) Man did that thing go. On GPS it had a top speed of mearly 27 mph with 1 person in it. It was almost too scary to open it up!

 

[bozza_boatie]

Re: 8hp or 6hp

Im going to buy a 8hp Tohatsu 2002 for $1200 Australian dollars. Ive decided on this motor as it weighs only 56pounds and doesnt have an inbulit tank.<br /><br />Thanks for helping me decide.

 

[Dunaruna]

Re: 8hp or 6hp

Bozza, some 'tinnies' are designed to accept extra bracing from the transom to the floor beams. Its not expensive (about $60.00) to get two braces welded in and it will give you peace of mind. Worth concidering.<br /><br />Aldo