wheres the power?

[dude33333]

hi all,<br /> i have a 17ft seasprite tri hull w/a 1975 johnson 50 hp. it has a control with warm up lever and one arm that puts it into gear and accelerates in one. anyways, i tried her out for the first time today in the saco river here in maine and it all went relativly well except for one thing, at full throttle i wasnt going more than 15 mph. i took a look with the cover off and it appeared to be depressing the throttle all the way but it didnt sound like it was going more than 3,000 rpm. then i put it into nuetral and manually pressed the throttle down and it sounded like it was going alot faster then. what is going on? i have a crappy propeller with a few little chips but 15mph? thats not right! whew! that was long! thanx in advance<br />~erk

 

[Solittle]

Re: wheres the power?

What is the rpm at wot (from a tach & not by ear)?

 

[dude33333]

Re: wheres the power?

hmm.... i wish i could tell ya, i havent got a tach. it is def. alot lower though. i guess thats sumthin i should get huh? oi im so broke its not funny

 

[R.Johnson]

Re: wheres the power?

Sounds like the engine is just running on just one cylinder, Check ignition, compression, and carb's.

 

[Chinewalker]

Re: wheres the power?

Hi Bunker,<br /> Definitely sounds like you're only running at part power. Could be a gummed up carb (there are two carbs - if one is working and the other isn't, the motor will still run, but major damage can occur from lack of lubrication on the associated cylinder), or it could be an ignition problem.<br /> A carb problem is relatively easy to diagnose - remove the front cover from the carbs and with the motor running, squirt some mixed fuel into both carbs. If the motor picks up speed on one of them, then that's the one that isn't providing fuel properly...<br /> After you've done that, check for spark at both plugs...<br />- Scott

 

[ledgefinder]

Re: wheres the power?

Alternately, you might be way over-propped. Those 50 twins don't have a lot of low end torque. Did you just get the motor, or did it rev out last year with no problems?

 

[dude33333]

Re: wheres the power?

ok heres the deal, i get spark in both cyliners and i can idel with either one disconnected, but on the top one alone, when i press the throttle it bogs out and dies. i asume its the carb? i used seafoam, sprayed in both till it stalled then put some in the cylinders, let it sit an hour then started it. should i do more to them?<br />thanx for replys<br />~erk

 

[cheverad]

Re: wheres the power?

I have a 1975 johnson 50 hp, and I had the the same problem last year . It ended up being my power pack. I paid $80.00 Canadian for a new one.

 

[cheverad]

Re: wheres the power?

$80.00 Canadian thats what $10.00 U.S. LOL

 

[dude33333]

Re: wheres the power?

power pack? is that like timing? what do other people think about this? i guess ill have someone look at it before i do much

 

[phatmanmike]

Re: wheres the power?

i had same prob with my 1980 50hp evinrude and then 2 days later i puked a connecting rod, cause the top carb was causing the number one cylinder to run so lean it wasnt firing right. i still had strong spak and fuel , all the "signs" of a good runner, but it was just enough to cause some serious havic......

 

[Walker]

Re: wheres the power?

Tear the carbs down and do a thorough cleaning. Use carb cleaner and compressed air and get every orafice and passage sparkling clean.