79 35hp Evinride- power loss

[jonboatbassin]

I was out on the lake last weekend going down the lake on plane and the boat was running good when it started loosing power. Since then its been running rough and does not have enough power to get back on plane. Motor still starts fine, runs smooth at idle and when in Neutral it revs up good and smooth but when in gear it gets rough/shaky and when I give it throttle it gets louder/rougher but doesnt give it much more speed. If anyone has any ideas for me to try to fix it please let me know. Motor needs to be fixed by Saturday.<br />Thanks alot<br />Adam

 

[OBJ]

Re: 79 35hp Evinride- power loss

Jon....without going through a complete check out...sounds like your losing a cylinder. When it starts to get rough, pull the spark plug wires one at a time. If there is no change, that's the cylinder thats' not firing.

 

[JB]

Re: 79 35hp Evinride- power loss

Howdy, JBB.<br /><br />You have lost a cylinder. Do not be fooled by what it sounds like with no load.<br /><br />Check for spark on both cylinders as OBJ suggests.<br /><br />Good luck. .

 

[jonboatbassin]

Re: 79 35hp Evinride- power loss

forgive my ignorance of motors--<br /><br />by losing a cylinder are you saying its gonna need some sort of rebuild or just that cylinder isnt firing and needs something as simple as a spark plug?<br /><br />thanks

 

[jonboatbassin]

Re: 79 35hp Evinride- power loss

ok, just ran the motor in a trashcan and while in nuetral i pulled each wire one at a time. both times it made it run horrible so im guessing that means i have not lost a cylinder.<br />something i noticed though is that my motor gets VERY VERY hot. after just a few minutes i touched the main piece that the plugs go into and it was way too hot to touch. i understand motors will have some heat but is this way too much? how can i correct this?<br /><br />thanks again

 

[jonboatbassin]

Re: 79 35hp Evinride- power loss

well i went and ran the motor again because i was curious about why it was getting so hot. i noticed that there is no water coming out of the hole on the bottom side where it used to and i traced the line back to where it comes out of the motor and it was completely dry. Shouldnt this have water coming out of it at all times, i dont know much about motors but I thought this was part of the cooling?<br /><br />let me know what you guys think<br /><br />Thanks again

 

[rrichard]

Re: 79 35hp Evinride- power loss

Sure sounds like you are overheating... Too hot to touch, water not present where it used to be...<br /><br />I would change the impeller (they're like spark plugs... Can't change them too often) and inspect the pump and passages for blockage while it's apart. If it's getting too hot to touch even briefly, then I don't think you want to run that outboard until it's fixed!

 

[wikelam]

Re: 79 35hp Evinride- power loss

A new impeller never hurts.

 

[jonboatbassin]

Re: 79 35hp Evinride- power loss

just went to get a new set of plugs for my motor and turns out it had the wrong ones in it from the previous owner. seems like its running a little better but i wont know for sure until I can take it out tomorrow. <br />when I ran the motor again the water was coming out off and on, so i dunno what the deal is with that....how hard is that to fix/replace?<br /><br />thanks

 

[rrichard]

Re: 79 35hp Evinride- power loss

Man, if that was my motor I sure would check the impeller before taking it out again...<br /><br />A new one should cost in the neighborhood of $20 and take about an hour to change your first time... Much less thereafter.<br /><br />Somebody posted a nice picture series of this being done...

 

[rrichard]

Re: 79 35hp Evinride- power loss

Found it:<br />Click Me

 

[Badfingers]

Re: 79 35hp Evinride- power loss

I would change the Impeller too,I just learned 1 of most $ lessons.I 115 Johnson I Smoke my Heads, Pistons, & Coils all @ once this Weekend. I now tearing it apart as we speak.

 

[jonboatbassin]

Re: 79 35hp Evinride- power loss

ok, just ran the motor this weekend and its still running like crap after new plugs. water pump is working fine and spittin water out of all the spots it should. <br />any suggestions?

 

[pbailey]

Re: 79 35hp Evinride- power loss

You ran the motor when it was to hot. Pump was not working when you ran it and couldn't put your hand on the heads. It dosn't take long to smoke an outboard, any motor for that matter when it's overheating.<br /><br />Take the heads off and look for scoring and other damage to the cylinder walls.<br /><br />pbailey

 

[pbailey]

Re: 79 35hp Evinride- power loss

It could have been a sticking thermostat as well.<br /><br />pbailey