Low end power

[racketoe]

I have a 1978 Evinrude 70hp on a 15' tri-hull, the boat brand is Dynamaglas, it is also a 1978. The motor starts and runs great, but seems to lack power out of the hole. Takes a long time to plane with two grown up and a 71lb child on board. It seems like the rpms take a long time to build. Once on plane it runs great, about 35 mph. The propeller is the standard 131/4by 17", which the manual says is standard for this long shaft motor. I can get the child up on skis, but not an adult. Is it just the age of the engine? Should I try a prop. with less pitch, or maybe rebuild the carbs? I'd appreciate any ideas. Thanks.

 

[DJ]

Re: Low end power

racketoe,<br /><br />Without a tachometer, it's dificult to say if you are propped correctly. That engine likes to turn 6K rpm, at wide open throttle.<br /><br />If the carbs. have never been touched-it's time.<br />First, take a look at your spark plugs. Do they all look the same? If not, you have carb. troubles.<br /><br />A 13 1/4" X 15" might be in order, especially if you are pulling something.<br /><br />First, take a look at your spark plugs. Do they all loook the same? If not, you have carb. troubles.

 

[ob]

Re: Low end power

Ditto on what djohns19 said.

 

[racketoe]

Re: Low end power

Djohns19 and Ob,<br /><br />Thanks a million for the help. You guys are great. I will check the plugs, and maybe spring for a tach.<br /><br />Thanks again,<br /><br />Racketoe