1976 70 hp johnson power loss

[minocqa]

hi<br />i bought this boat and 76 70hp johnson motor brand new in 1976 <br />the motor hasnt had anythng done to it other than i winterize it in the fall and change the plugs in the spring.. for some reason this summer, the motor doesnt seem to have the power that it once had. it used to push the boat about 40 mph but now i'm lucky to get 25mph. It starts right up idles well but sometimes dies upon excelleration. i was wondering if any of you had this problem before and what you think might be causing it. <br />thank you for any help you can give me.<br />Don

 

[DJ]

Re: 1976 70 hp johnson power loss

If you have good spark on all three cylinders, I would say it's time for carburetor overhauls.

 

[Hooty]

Re: 1976 70 hp johnson power loss

...and while the wrench is at it, get the waterpump rebuilt. It's time. <br /><br />c/6<br /><br />Hooty

 

[minocqa]

Re: 1976 70 hp johnson power loss

hi<br />thanks for the replies <br />my only concern about rebuildiung the carb's is getting them in sync. aferwards is this hard to do?<br />also could you tell me, is there a kit to rebuild the water pump or what parts do i need for it. there is some guy on ebay selling a waterpump plate for this size motor is that something that i woiuld need?<br />thanks again<br />Don

 

[DJ]

Re: 1976 70 hp johnson power loss

miocqa.<br /><br />The "sych. and link" procedure is not hard, if you follow a good manual-about $30.00. You'll be glad you have it, down the road.<br /><br />They are available on this site-lower left corner of page. I think the Seloc manuals are better.<br /><br />You can buy the water pump rebuild kits from many sources. I would buy the complete kit, since you do not know the condition of the wear plate and housing.

 

[minocqa]

Re: 1976 70 hp johnson power loss

thank you very much for your advise. .. i have purchased a johnson factory service manual off ebay that is made just for my year of boat motor. but i havent recived it as yet. i hope it will have help answer some of my questions<br />thanks again<br />Don

 

[DJ]

Re: 1976 70 hp johnson power loss

Don,<br /><br />Perfect. The OEM manuals are the best. Good choice. They are very thorough and will make your repairs a snap.

 

[minocqa]

Re: 1976 70 hp johnson power loss

thanks<br />at least i'm doing something right i guess hahahaha <br />i guess i have just been lucky all these years that i havent had major motor problems.<br />i try and take really good care of my boat its 27 years old but it doesnt look it, i'm always getting complements on it no one can belive its as old as it is. this is the first year i have had any problems with it. <br />thanks again<br />Don