1989 Evinrude 225 Issue

RoughFishAssassins

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Ok, I have been hunting all over this site for an answer and just can't seem to find one. Here is my story:

I recently bought this 1989 evinrude 225 to replace my 1977 evinrude 115, great upgrade. I checked everything over as best I could on the stand, noticed that the VRO was disconnected, started the motor, on mixed gas, that had apparently not run in 2 years. It started great and ran surprisingly well on the stand. We pulled the trigger and did the motor swap, but not before changing the water pump assembly. With the motor on the boat we decided to take it out for a maiden voyage. all seemed to be running great for us. We varied the throttle to just re break in the motor from its slumber. After about an hour of running it, the motor took off, we actually gained another 5 plus mph. All we could think is it has finally broke free and is ready. Satisfied we returned to the launch and went home. The next couple times that we went out, the motor would run good, never at that wot point we had seen briefly, but it was running good, then things started going down hill. after a while the motor would pulse, or surge, but never get above the 3000 rpm range. We figured it was going into the slow mode, but honestly unsure. We have been running the motor and every once and awhile it would just take off to that WOT area but never long lived.
I have replaced the fuel line thinking that could be an issue, but it never changed, I have checked t-stats and they are working, checked the overheat alarm to make sure that works (was a fear that the sensors were bad) even tested the sensors and that made no difference. I am running out of ideas, my last idea is to change the power pack, but wanted to see if anyone could give me a little insite on this. I had it arranged to go to a shop, but after looking at it the shop turned it away do to the fact that the motor is bigger than what should be on the boat according to the coast guard. Please Help, you guys were great before.
 

ondarvr

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Apr 6, 2005
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You need to start checkings things, compression, spark, clean the carbs,, etc.

Electrical problems tend to act up like someone is flipping a light swtich, it can instantly run better or worse, fuel issues tend to act more slowly, surging up or down, but more smoothly.

Coils go bad frequently and may intermitenly fail and then run correctly.
 

RoughFishAssassins

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The compression was tested before we ever put gas to it and it was good, even checked again after we ran it some. The other night the motor was running for crap, pulled the cover and found one of the plug wires had separated. Fixed that problem and it was better, or atleast back to the way it was prior. Is the power pack a likely issue? While discussing with the mechanic he state that it could be but that was in a list of things that it "could be". I hate to fixe a motor by throwing parts at it. I just don't understand how we hit WOT like it was supposed to but more times than not we don't even get there before it acts up.
 

ondarvr

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If you don't want to just start throwing parts at it, do a little testing. You haven't said exactly what the symptoms are yet, other than it being inconsistent, is the surging instant, or is it slow and even? Pull one plug wire off at time and see how it runs, this can identify which cylinder(s) has a problem.

What were the compression numbers?
 

racerone

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Run with a timing light hooked up.----One cylinder at a time to look for possible ignition issues.
 

RoughFishAssassins

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The motor runs fine in idle on the muffs, but when it is in water usually within a couple minutes of travel the rpms start to drop into a range of 2500 to 3500 rpms and wont go above. some times it will surge but never consistent. The only thing that is truly consistent is the lose of rpms. when that happens I can idle the motor back down and put in neutral and it runs fine, work back up to WOT and within a min or less it looses rpms again. I get the longest run without it happening when the motor is "cold".
The last time I had it out one of the plug wires ended up getting pulled, the way the motor acted then is not the way it is acting other times.

I kinda understand the timing light point, but will this be able to be picked up even at idle? or should this be done out on the water?

If I need to throw parts at it that is fine, but what parts would be the most likely culprit? I have new plugs and wires sitting here waiting to go on, but feel that there is more to it than plugs and wires and would just like to change it all at once and hope for the best.

Can parts be tested without running the motor to find out if they are weak or failed/failing? I am not a mechanic, but do know enough to be dangerous, I am a HVAC/R service tech, I know its not the best, but I do understand electrical and the basics of how the motor works.
 

racerone

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Many motors will run just " fine " on the muffs.---A V-6 will sound fine to the untrained ear when hitting on 5 of 6 cylinders.----So run out on the lake with a timing light and see if spark is an issue !!!!-----Simple testing techniques get you answers to the problem.
 
Last edited:

Drummerhowie

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It sounds like one or more coils are breaking down once they heat up. Try to find someone with a coil tester and bring them the coils. We would hook these up in school and let them run for awhile. At first they would have a nice blue spark, but once they warmed up the spark would dwindle down and die. I had a. buddy with an old inline 6 mercury that did that....three of six of the coils would die out once heated up.
 

Drummerhowie

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I just noticed that you're an HVAC'R. I was one for 15 years and teach it now in Orlando. Rock on, and good luck!
 

RoughFishAssassins

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Question about the timing light deal, if the spark is the problem, then why when i idle down after i loose rpm, and then work throttle back up, is the problem briefly gone? I would think that after i loose spark that it would stay hone or irradick?

Also i ohmed the coils and the all ohmed close to each other. But when i ohmed from thru power pack to the coil i got: (coil 1) 115.4 (2) 138.8 (3) 105.4 (4) 113.8 (5) 107.7 (6) 105.7
Are these close enough to be considered good ?
 

RoughFishAssassins

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Well i replaced the power pack, coils, plugs, and plug wires but the issue is still there. The motor never got above 3500 rpms, and it did before. If we leave it less than WOT it seems to run good but not to where i feel it should be. If we run wot a little time later it will start to surge. Did go squeeze the primer bulb when it did this but no change.
We have a big trip coming this next weekend and are hoping to have this cured for it....please help give me direction
 

ondarvr

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You haven't told us if the surging or loss of RPMs is sudden, or smooth, nor if you have cleaned the carbs, or the compression numbers.

Did you use a timing light to check for spark, or have you pulled the plug wires one at a time.

Everything you've replaced could have been eliminated as a problem had you done a little testing first. Probably an hours worth of work.

Try running it without the cowl on and see what happens.
 

RoughFishAssassins

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I guess you could day rpm lose is smooth. It just slowly looses rpms. It runs ok then shortly later it slowly loses rpms with surging/pulsing.
Compression all 6 cylinders were within 5 pounds of each other. Carbs have not been cleaned. I did not pull plugs as running (motor isnt easiest to get to)
Did run it with cowl off and no difference either.
I dont have access to a timing light right now, and have to trailer 30 mins to get to water to run the motor so i am trying to fix as much as i can off the water
 

ondarvr

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Smooth surging is an indicator of fuel delivery issues (not in every case, but normally is), fuel pump, air leak, dirty carbs, etc, it can also detroy the motor if you run it that way.

Squeezing the primer bulb sort of rules out the fuel pump, and possibly an air leak in a fuel line, so jump in and clean the carbs thoroughly.

Taking the cowl off eliminates a leaking base gasket allowing exhaust to be ingested by the carbs.
 

RoughFishAssassins

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May 9, 2010
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Was talking with a couple locals and they asked about the prop. I guess i never realized that it could be that. Looking at it we are running a 24 foot pontoon with 27 inch toons and the prop is a 14.5x20, am i gonna kick myself for over looking that?
 
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