'85 Evinrude 150 v6 Problems

[sabbett4]

Replaced VRO pump with replacement kit 6-7 years ago
Cleaned Carbs and replacement kit 6 years ago w/ minimal use since
Use Seafoam on about every fill up
Cold Compression test: 95,83???,93,93,93,90 (just checked)
6 years ago compression was all between 80-85 (wondering if Seafoam made a difference)

I have had problems with this motor for the past 8-9 years. I continue to think its a fuel issue, but I'm just not sure. Sometimes it runs like a champ, and then half the time it bogs down at WOT. Sometimes I can save it from dying, but other times I can't. Once it does this, I can't get it to power up all the way at WOT. Sometimes I can run it half way after this happens. Other times, I have to idle back in. I've had days where it does this, then I go out the next day and it runs like a champ again. I just don't get it. I use to have problems with it planing out, but haven't lately (I used to think my prop was part of the problem).

Any ideas? Also, would my one cylinder in the 80's be part of the problem?

Please help! Thanks!

 

[racerone]

I would find a shop that has a dynamometer.----Have the motor tested to see if it producing the proper power.

 

[Faztbullet]

I going to lean toward a timer base failing more than a fuel problem....

 

[sabbett4]

Thanks for the input, guys. Faztbullet, what step do you recommend taking next? Also, should I be concerned with the one lower compression reading?
Any advice on this is greatly appreciated!!

 

[racerone]

Well, you could remove the bypass cover and look at that piston and rings.----Will cost you a few minutes and a $2.00 gasket

 

[Faztbullet]

Take a timing light with ya next time ya go out, when it starts acting up check all cylinders for spark. Also this model was prone to have bad plug wires...

 

[hondam]

You can look up the ohm readings for your timer base on the CDI website. Make sure your using a decent multimeter to get good readings.

Also try changing the check valve in the intake manifold.

 

[emdsapmgr]

Fuel issues don't usually come and go. Ignition troubles do. Weak ignition components tend to fail once the engine heats up to normal operating temps. May run ok when cold, then crap out once it warms up. There is an easy test you can do. If you do the timing light test and you see no firing on one side of the engine: swap the two power packs. They are identical. If the problem moves to the other side-likely a pack is bad-replace it. Agree with hondam. Go to this website: cdielectronics.com and look up your engine in the electrical troubleshooting section. There are excellent ignition values for the main components of your ignition system. For instance the cranking voltage outputs could be .6 volts for the timer base and minimum 150 volts for the stator. Check the text for the exact values for your engine.Test once the engine is warmed up. You will need a special "peak reading" voltmeter. A typical household meter won't work. All of these ignition components are expensive, so you will save yourself $ if you test first-before you just start throwing parts at it. 5 of the cyls have normal compression-one is low. The low cylinder is outside the normal permissible 10%, so while it may fire, you won't make good hp from that hole. Probably good to check the top ring on that low compression piston.