1989 Evinrude V4 120 hp power loss at wot

[gevans]

I'm new to iboat, and new to boating in general.<br />After reading 15 pages of forums, I have to ask for your assistance. I purchased a Stratos 284 bass boat with an 1989 Evinrude V4 120hp engine.<br />Model# E120TLCEM Serial#333686 I went out to test it this weekend and it ran like a champ at full throttle for about 8-9 minutes and then just cut out. I restarted it and it stalled again. Thinking it was an overheat condition, I threw the trolling motor in and headed back to the launch. After 40 min. of trolling, the batts. went dead. I restarted the engine and it ran fine back to the launch ramp approx a mile away. It's been trailered since, because I'm not sure what caused it. I'm thinking about taking it to a dealer for tune up, but after reading your forums, I believe there are a few things I can look at myself, with your guidance. Such as spark gaps, cracked coils, fuel filter, plug wires ect... Love your ideas and tricks to try in the forum section. I don't feel so much like a dummy when I read your advice. Any suggestions you have are important information to me. Thanks in advance gents...

 

[JB]

Re: 1989 Evinrude V4 120 hp power loss at wot

Evinrude Trouble

 

[Walker]

Re: 1989 Evinrude V4 120 hp power loss at wot

The first thing you have to determine is was it overheating or not. Does you alarm system work and are your temp sensors functioning properly. <br />Next, did your motor quit from lack of spark or a fuel problem. You need to make it do it again and then test for spark immediately. Bad Powerpacks sometimes work fine until they get warm. Sometimes you can test them for this problem by running your engine on muffs and heating up the powerpack with a hair dryer.

 

[gevans]

Re: 1989 Evinrude V4 120 hp power loss at wot

Originally posted by Walker:<br /> The first thing you have to determine is was it overheating or not. Does you alarm system work and are your temp sensors functioning properly. <br />Next, did your motor quit from lack of spark or a fuel problem. You need to make it do it again and then test for spark immediately. Bad Powerpacks sometimes work fine until they get warm. Sometimes you can test them for this problem by running your engine on muffs and heating up the powerpack with a hair dryer.

 

[gevans]

Re: 1989 Evinrude V4 120 hp power loss at wot

Walker, thanks for the reply. My boating friend asked me to look at the plugs right away, and when I did they were fouled with carbon build-up.<br />I replaced them with new ones just today, and gapped them properly. Took the boat over to the lake, and it ran like a top for an hour straight.<br />Not one problem! But I'm not sure that everything is back to normal until I run it again.<br />Do you think that this might have corrected the problem, or might it be something still?<br />It just seemed to easy a fix.....Thanks Again!!

 

[djzyla1980]

Re: 1989 Evinrude V4 120 hp power loss at wot

Fouling plugs could have caused your problem... Do you know the history on this motor. When the impellor was replaced last, If it has been decarbed?<br /><br />If you are unsure of these then I would suggest doing that at the least.<br /><br />I figured out in a short period that there are 3 types of problems:<br />1- you spend hours on end looking for a problem that seems to be no fix<br />2-you waste much time and effort into finding the problem and it's an easy fix right in front of your face.<br />or you get lucky and<br />3-you try one of the least time and $ consumption item(s) and it works <br /><br />Maybe you rolled the dice and won... sometimes it sounds to easy to be true-but the only way to tell is to run it!! If you still have problems with fouling plugs... I would test spark/compression and if all looks good check out the carbs next. Might be time for a carb clean and rebuild.

 

[Walker]

Re: 1989 Evinrude V4 120 hp power loss at wot

If the new plugs do the same thing then I'd check idle timing and all the recirculation valves for proper operation.