1984 Evinrude 150 weird sound.

[MGuckin]

With the motor running on muffs, I hear a sound, almost like a compression release at idle and see a little puff of exhaust but can't isolate where it is comng from. Any ideas? Motor runs great. Sound and puff are coming from the area just aft of the fuel pump.<br />Thanks,<br />Mike <br />

 

[seahorse5]

Re: 1984 Evinrude 150 weird sound.

Those older V6's commonly burned out an area of the powerhead to mid-section gasket. Are there any black stains on the mid-section near the upper motor mounts and steering arm? Are there any black oil drips down the side?<br /><br />Another thing might be a crankcase leak near the pulse line for the pump or where the crankcase comes together. It might be flashlite and dental mirror time.

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

seahorse,<br />I was thinking about a blown case gasket but hoping I was wrong. No stains or oil on motor. Already cleaned it and ran it to make sure.<br />Mike

 

[Dhadley]

Re: 1984 Evinrude 150 weird sound.

There is no gasket between the block and front half. Hopefully you have a by-pass gasket leaking. pull the pump off and remove the cover (6 bolts) to replace the gasket. <br /><br />Good luck!

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

Dhadley,<br />Leak isn't coming from the pump. But a few inches aft. I am working on it now. Supposed to be another crankcase pulse port that is capped that might be leaking? Used for separate pumps?<br />Mike

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

Dhadley, Rereading your last post I misunderstood. Plate is behind the pump correct? Not the pump itself. <br />This leak is driving me crazy. Keeps moving around. Acts like the pressure builds and dumps where it can. Thought it might have been in sync with the crank pulse but not consistent leak times. Makes no difference whether motor is warm or cold. Motor does skip? for lack of a better term. when it exhausts.<br />VRO is capped and harness unplugged. <br />Starts like an OMC. Motor runs excellent once warmed up. <br />Noticed this about a month ago. Just trying to work out any minor bugs. <br />Found out my throttle cam was binding and fixed that. Was stopping about 30 degrees shy of wide open. Haven't tried that yet, figured I would fix this first.<br />Any help that you or others may offer is appreciated.<br />Mike

 

[Dhadley]

Re: 1984 Evinrude 150 weird sound.

Exactly. There are 3 by-pass covers on each side. Once you get the pump out of the way you can probably see where its leaking. You can still run the motor after moving the pump to get a better view. <br /><br />Let me know how you make out. Good luck!!

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

I cleaned off the plate while it was installed and wiped a bead of gasket sealer on it just to make it easier to see if gaskets blown out. Figured it might bubble out. Looks like you were right. Gasket blown out on bottom plate. I think I will change all 3 of them while I am it. Off to the part store this morning. Hopefully a stock item.<br />What is the purpose of this plate? No explanation in the manual.<br />Thanks<br />Mike

 

[BKool68]

Re: 1984 Evinrude 150 weird sound.

I believe the plate is a cover for where your intake charge enters the cylinder. It directs the charge into the cylinder and also covers the area where the intake ports were drilled in the cylinders.

 

[Dhadley]

Re: 1984 Evinrude 150 weird sound.

OK, before you put the covers back on, take a straight edge and make sure its straight. Especially around the area that was leaking. It doesnt have to be perfect but it should be really close.<br /><br />Let us know!

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

Fairly straight. Few burrs which I removed nothing major. I noticed on the starboard side the covers are sealed with RTV Red. Don't like using gasket sealer but do to the age maybe I should? It would build up any imperfections.<br />Thanks<br />Mike

 

[MGuckin]

Re: 1984 Evinrude 150 weird sound.

It is back together. Found 2 bad gaskets. Bolts were loose on them. Probably from vibrations and lack of retorquing. Changed all 3 on port side and sealed with RTV red. Motor sounded totally different once started. Idle not as erratic. Ran on muffs @ 1200 rpm for about 1/2 hour. Never heard it leak. Gonna water test it tomorrow weather permitting. Will let you now.<br />Thanks,<br />Mike<br />

 

[DJ]

Re: 1984 Evinrude 150 weird sound.

MG,<br /><br />GOOD JOB!! <br /><br />DHadley has been very helpful to me too. Thanks DH.

 

[Dhadley]

Re: 1984 Evinrude 150 weird sound.

Sorry for the delay in response but I have been on the road. Glad you got everything back in running order. And thanks for the kind words, Djohns19.<br /><br />Enjoy!