Losing power 1989 50hp 3cyl

[Keith Buchanan]

Coming back from a trip recently engine started losing power and surging back intermittently, checked plugs etc, think it is a fuel problem, ran it on a tank of premix to discount oil injection unit and it still did the same. Checked fuel lines etc still no idea. Any tips on diagnosing this problem welcomed..<br /><br />Keith B...

 

[Keith Buchanan]

Re: Losing power 1989 50hp 3cyl

Have just got to the inline juice filter on the starboard side and it is clear. When the rev retention occurs if I completely throttle back for a short time and then WOT it picks up like it should for a few seconds and then bogs down...then out of the blue it will try to pick it's feet up again. Also if I maintain neutral gear and raise the rev's to a high level with the idle throttle then shut down and then engage gear I get a better response.

 

[achris]

Re: Losing power 1989 50hp 3cyl

KB,<br /><br />These engines are really touchy with spark plugs. Try replacing them first.<br /><br />Chris...........

 

[andrewkafp]

Re: Losing power 1989 50hp 3cyl

Are you sure that the leg wasn't dragging the bottom ?? It happened to me last year with same symtoms until I lookeed at the sounder and it read 2ft <br />Then I saw the sand churning up....

 

[Keith Buchanan]

Re: Losing power 1989 50hp 3cyl

The water I am normally in is 20ft minimum but after having the front cover off to expose the carbs and spraying premix in I now dont think it is a juice problem. Going down Chris's path I have now renewed the HT leads and am now in the process of finding a local stockist that can supply the spark plugs.<br /><br />Thanks all, Keith B..

 

[Elmer Fudge]

Re: Losing power 1989 50hp 3cyl

Hi Keithy B... Check the fuel pump it could be a faulty diaphram, also if you can, do a compression test on all cylinders, the results should be within 10% of each other.<br />Sometimes a little crud get's into the carbs or you may have some carbon build up, in any case give them a good cleaning out, decarbing never hurts, lets know the out come

 

[Keith Buchanan]

Re: Losing power 1989 50hp 3cyl

Is there any non intrusive way of cleaning carbs ie, chemicals etc. I,m not too happy about pulling carbs apart.

 

[Elmer Fudge]

Re: Losing power 1989 50hp 3cyl

Go to the top of this page, right next to search there is the FAQ section, click on FAQ and look for decarb

 

[Keith Buchanan]

Re: Losing power 1989 50hp 3cyl

Cheers EF<br /><br />Cant seem to find Seafoam here in the UK, any takers on a compareable product over here.<br /><br />Regards Keith B..

 

[Elmer Fudge]

Re: Losing power 1989 50hp 3cyl

Try mercury's Quicksilver power tune,or see what the marine dealers have to offer that's comparable.

 

[Keith Buchanan]

Re: Losing power 1989 50hp 3cyl

Well thanks go out to all you guys and let's not forget the people that host and maintain this site to make it possible. After fitting a pump diaphram kit I gave it a go at the local riverside slipway and things went pretty well. It also now has a new set of sparkplugs and leads and a new fuel filter.<br /><br />Just one interesting observation with this problem was every post I looked at mentioned the pump diaphram being perished or the posibillity of a perforation. This was definately not the cause in this case, I had 400w of high pressure sodium lamp behind the old diaphrams and not one speck of light penetrated. The diaphrams were very stretched though with the action of the sprung buffers either side and I was wondering if anybody else had suffered the same problem of saggy diaphrams. (Please keep it clean, there are children about..!!)<br /><br />Thanx all....Keith B....