69 johnson 55hp preformace?

[Txsmaidfleet]

Hello I have a 69 johnson 55hp that runs great good compression on my texas maid fleet 16' aluminum, Prop has no visible marking on the outside will have to remove it to see if I can find them but I had the boat out this whole week and it ran just great started up no problems but I feel it lacks preformace I know this may be a open question but what top speed would you expect and would expect it to be able to pull a tuber/skier, boat+gear+motor+people= about 1500lbs, I manage to ski behind her but it was a struggle to get up and I'm a small guy 140lbs wet and I pulled some tubers all were above 170lbs it was also a struggle to get on plane. I made about 23mph with me in the boat and about 20 with a friend. I feel I need to do some more fine tuning as I just managed to finish getting the motor on before we left for the week vacation. I would like to hit 30 mph and easily tow tubes and skiers does this seem reasonable?
thank you in advance

My old boat

 

[sutor623]

Re: 69 johnson 55hp preformace?

Hey bud. Check your coastguard tag and see what transom is rated for hp wise. 55hp on that boat seems underrated to me. That's WITHOUT pulling a skier. I don't think you will get on plane with that many people and pulling a tube/ skier. Im also guessing it has no tilt/trim because of the age. if thats the case it would be even harder to get on plane and stay there. I have a 16' aluminum boat with a 75hp and with two on board we can go 34mph. With three on deck an a skier, maybe 27mph wide open. If I had a 55 on there there's no way I could pull anything behind me. Honestly if I were you I'd enjoy what I had!! Glad she runs good. Maybe if you were thinking upgrade that could be a winter project.....

 

[Txsmaidfleet]

Re: 69 johnson 55hp preformace?

tag is 75hp, and the motor is all manual I played around with a few different holes to trim found the "best", maybe 30 mph is a bit high The cottage I go to is on a small lake and my top speed of almost 25 is ok but feel like I need more out of the hole.

forgot to mention the motor was given to me by a friend as his grand father was the only one who could get it started, other than me breaking the fuel pump while taking off the old fuel lines and checking the carb's....The only thing I found wrong was incorrect spark plugs....

Im into the boat cheap as well, I have a dol-fin on the speeditwin that use to be on the boat I think I may try it on the 55...

 

[boobie]

Re: 69 johnson 55hp preformace?

What size prop do you have on it ??

 

[Txsmaidfleet]

Re: 69 johnson 55hp preformace?

prop size is 13 1/4 x 17, I have no tach as of yet but boat does not seem to be running at high rpms and is not getting hot I was able to place my hand directly to the head right after pulling a tube. I am stern heavy with the motor gas tank and battery.

 

[sutor623]

Re: 69 johnson 55hp preformace?

Hmm too bad you dont have a tach. My guess is that the 17p is bogging the engine down a bit, (meaning a prop downsize may be in order) but no way to know without reading rpms. You def need to get a tach if you want to get the best performance out of your rig.

 

[boobie]

Re: 69 johnson 55hp preformace?

Try a 13 1/4 x 15 on it once and see what happens.

 

[Txsmaidfleet]

Re: 69 johnson 55hp preformace?

maybe I should have placed this in the prop section but Im thinking of going with a 13x15 4 blade, looks like from what I am reading the four blade will help the boat plane out faster...I will loose some top end but I think if I can stay in the 20-25 mph range on plane I would be happy.

Quick story Went to a local lake today took the nieces and nephews for a day of tubing. I just bought a new tube one of the flat two person ones thinking it would pull better....I couldn't even get it to plane out with a 100lb kid on the back going to take the tube back as I was able to plane out with a standard tube and a 300lb male..So after my own sadness of the new tubes failure I noticed the sky was black as night and getting closer. I told the kids it was time for us to get off the lake and we made our way to the beach where i picked them up from, after dropping them off I towed a boat back to shore that two guys couldnt get running while towing them it hit....I told the guys they could walk the boat in and then the wind kicked up and blew me too close to shore I had to beach the boat as this little lake became the ocean with white caps and 40 mph winds....during a break in the wind I pushed the boat back in and flew across the lake to the boat launch...without my windscreen I never would have been able to see as at the half way point the wind kicked up again. I jumped out of the boat lashed it to the dock and had it it on the trailer in record time.....after getting the boat strapped I went to pull the drain plug and water had collected up to the carpet....this was in only 15 min....but the boat ran great haha what a fun day at the lake

 

[sutor623]

Re: 69 johnson 55hp preformace?

Its cool that you helped someone get off the lake before that storm. And yes, if I were you I'd move this topic to the prop section. Steelespike is the MAN over there, he'll be able to set you straight! I too am wondering if a 4 blade would help you plane out easier with the sacrifice of a few MPH. But changing over to a 4 blade from a 3, and changing pitch/diameter is a science! You almost need to go to a prop shop or dealer and ask them to try out a prop. Tell them you will buy the one you like, but you have to find it first.