how fast should a 1979 55hp run??

[sandollar1978]

Hello again!! How fast should a 1979 55hp evinrude motor run on a 1978 15' Sandollar boat the fasts I could get it to pick up is about 15mph. Our what should I do? it starts up fine and sounds great but just no power when you run it!! Any help would be great!!

 

[JB]

Re: how fast should a 1979 55hp run??

I suspect that you are only running on one cylinder, Sandollar. Those engines sound fine on one.<br /><br />With the engine idling, squirt some fuel mix into each carb. Does it pick up rpm on one of them? If so that carb is plugged up.<br /><br />If that doesn't make any difference, disable each spark plug, one at a time (Carefully ). Does the engine die on one, but keeps running when the other is dead? The one that doesn't make a difference has no spark. Troubleshoot your ignition system.<br /><br />Let us know what you find and if you need more help.<br /><br />You will need a Manual.<br /> http://www.boatmotors.com/manuals.html

 

[sandollar1978]

Re: how fast should a 1979 55hp run??

Thanks JB that was a fast reply! I'll try what you said and post a reply!! thanks again..

 

[steviecops]

Re: how fast should a 1979 55hp run??

I've got a 1980 Johnson 55, and on my 17 ft cathederal hull fishing boat, fully loaded with 2 persons on board,(weighs about 1000 lbs), it pulls 21-22 knots according to the GPS. I'm not sure, but I think that equates to about 30 mph.

 

[sandollar1978]

Re: how fast should a 1979 55hp run??

30mph is it fast for a 55hp motor? My boat is only 15' feet fiber glass boat and it seems like it goes realy slow and the speed meter marks 40 mph and the boat runing marks about 15mph I wish I could get up to 30mph that would be great!!

 

[steviecops]

Re: how fast should a 1979 55hp run??

Maybe hull design has something to do with it.<br /><br />My boat is a fibre glass Dory, (Tri-hull), and it sits pretty high in the water, therefore it doesn't take much to get it up and planing.<br /><br />The 21-22 knots is WOT, it is much more economical when running at between 13-15 knots.

 

[sandollar1978]

Re: how fast should a 1979 55hp run??

maybe you could send a picture of your boat my email is 1978sandollar@comcast.net I'll sent you a pick of my sandollar!

 

[DJ]

Re: how fast should a 1979 55hp run??

1978 Sandollar,<br /><br />Boat speedometers are notoriously innacurate.<br /><br />If you really want to know how well your engine is running, get a tachometer. It should turn between 5-6000 rpm.

 

[sandollar1978]

Re: how fast should a 1979 55hp run??

Thanks, could I use any rpm tac like a auto tac and if so where do you connect it? thanks for the help...

 

[rolmops]

Re: how fast should a 1979 55hp run??

Hello.<br />The most accurate and easiest to install tachometer would be a "tiny tach".Just type those words in on your search engine get the phone number,call them and explain what you need it for. Also measure the distance between your lower spark plug wire and the place on the dash board where you want it to be,because they will custom cut the wire length you need.I was happily surprised by their service level.

 

[sandollar1978]

Re: how fast should a 1979 55hp run??

Great info thanks I look it up with google.

 

[papasage]

Re: how fast should a 1979 55hp run??

my 1979 on a bumbee bass boat will run over 30 havent checked with any speed checking devise . you probabley have lost a cylinder . one cylinder will make a lot of difference.bumble bee is a heavy boat.check the firing & compression . papasage

 

[rickdb1boat]

Re: how fast should a 1979 55hp run??

When I had a 65 HP Merc on my 15' wellcraft, I ran about 37 MPH. Just thought I would throw that in there for comparison....