50 HP Evinrude (1996) - bogs down at WOT

[kyfike]

Motor will sometimes - but not always - bog down at WOT. Problem erratic - occuring about every other time it's started. <br />One time, pumping priming bulb helped - other times it didn't. Yesterday shut motor off and waited for a minute and it ran fine but only for less than a minute; shut down again for 5 minutes and it ran fine for the 20 minute run. Today it ran fine for the 30 minute run.<br /><br />Mechanic tuned motor, including rebuilt carbs and new fuel filter, late last year (15 hours run time since). In past two weeks, mechanic replaced power pack, priming bulb, and pulled and cleaned the fuel tank. Found the fuel filter only 1/3 full today but motor sat over night with trim all the way up - is that typical? One mechanic said the fuel pump is either good or bad and will not come and go - another said it's the fuel pump. Fuel tank vent is not the problem - removed it and the problem continued.<br />Tired of paying $65/hr for a mechanic to guess at solution - should I go for a new fuel pump next?

 

[fireman57]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Next time it bogs check for spark with a good set of insulated pliers. If you spark is good then we'll go back to looking at fuel. It might have just been a coincidence that it cleared the one time you pumped the primer bulb.

 

[kyfike]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Fireman - thanks for the quick response.<br />I agree that it was probably a coincidence that the priming bulb helped that one time. This is my first boat and am completely unfamiliar with outboards - question: the mechanic said the power pack had been replaced several weeks ago when a PM check found the motor to be firing on only one cylinder. I can find nothing that looks new under the cover and I wonder if it was really replaced. Can the power pack "come and go"?

 

[davejnz]

Re: 50 HP Evinrude (1996) - bogs down at WOT

do a search for fuel pump test.I think you simply remove the outlet fuel hose from the fuel pump to carb and try to blow through it.If you can,the pump is bad.Do the search though for the detailed instructions.

 

[joe_morgan]

Re: 50 HP Evinrude (1996) - bogs down at WOT

I've just recently had a issue with misfire and bogdown at OWT. I reset the point and it running like a champo now. Its probably been done with everything else that was done, but its worth a look.<br />Joe

 

[fireman57]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Powerpacks don't come and go. You could have a bad ground or connection somewhere. Remove and clean well all connections especially the grounds. Make sure that your battery cable are very clean and tight. Do not use wingnuts. Get a good pair of stainless nuts and tighten with a wrench. Any difference in current can fry a pack.

 

[Silvertip]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Yes, power packs definitely can come and go. Not often -- but they can be intermittent. I had one that simply squeezing the potting compound on the bottom of the pack caused it to fail, come to life, fail.

 

[fireman57]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Upinsmoke I guess what I meant was they are either good or they are bad. Your's was bad but you figured out what it was.

 

[fireman57]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Upinsmoke I guess what I meant was they are either good or they are bad. Your's was bad but you figured out what it was. Sorry for the confusion.

 

[kyfike]

Re: 50 HP Evinrude (1996) - bogs down at WOT

Gotta believe the problem is electrical. When the mechanic found one cylinder not firing when he summerized it that is the problem that still exists sporadically. Installing the power pack did not solve the problem but just seemed to as the problem disappeared temporarily. I'll run it this weekend and check for spark when it breaks down at WOT

 

[kyfike]

Re: 50 HP Evinrude (1996) - bogs down at WOT

I gave up and took the motor to another shop and they found the power pack bad. Over time, the problem had become worse and it was easier for the real mechanic to diagnose and fix it. <br /><br />I'm not sure if the first shop actually replaced the power pack or not since it ran bad after it was first launched - immediately after the power pack was supposedly replaced. <br /><br />Thanks for all your suggestions - much appreciated.