1991 Evinrude 150 powerhead check valves

cowboyup

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Upon inspecting my repaired powerhead, i noticed three small, oil passage holes for the crank and three small holes on both faces where the intake manifolds mount. I've cleaned all the oil and drain passages with compressed air. Which ones are supposed to be check valves? And wich way are they supposed to direct flow? Thanks ahead of time.
 

angus63

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Re: 1991 Evinrude 150 powerhead check valves

I believe you are talking about the recirculation valves. Routing is in manual (DO NOT GUESS). Easy way is check any early 90's 150/175hp motor for recirc valve locations and hose layout.<br />Good Luck
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

I've been looking through my OMC service manual to find out if those brass colored inserts (in the powerhead itself...three on each side where the intake manifolds mount) are check valves or just straight bore oil passages. It does very clearly illustrate the routing of the hoses but does not show the location of the in-line check valves. My parts catalog only shows 3 in-line check valves but again, no location.
 

angus63

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Re: 1991 Evinrude 150 powerhead check valves

The brass fittings are the valves (one per cyl). Soak em in alcohol and blow them out before reusing.
 

Walker

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Re: 1991 Evinrude 150 powerhead check valves

The check valves are on the intake manifold and have a 5/15" or 3/8" head on them and can be unscrewed. The other ends of the hoses go to nipples that are just pressed in. The check valves are one way flow outward to the hose.
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

I hooked up my compressor air hose to the 90 degree nipple (on the powerhead) on the back side of where the intake manifold mounts. I heard air coming from the brass pressed in fitting on the same side (opposite from nipple) as the intake manifold mounts. I heard a little air, but when i pressed a paperclip end slightly inward (inside the brass fitting), the air rushed out. They must be a combination 90 degree nipple and check valve pressed in. Question is, how can i replace (press out) these. Do i heat it up with a heat gun, butane torch or other. Are they sealed in with gasket maker or some other goo? I've got three that the check valve is missing (#1,#4,#6). Question #2 is, what harm will it do if i don't replace them? thanks again.
 

Walker

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Re: 1991 Evinrude 150 powerhead check valves

I don't believe that's a check valve. And the ones that are missing do need to be there. You will have running problems without them and also will have raw fuel spitting out the holes into you powerhead compartment. Good way to set your motor on fire.
 

seahorse5

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Re: 1991 Evinrude 150 powerhead check valves

Give us your model number as there were 90 degree 150's and 60 degree 150's that year, and each had different designs and recirculation systems.<br /><br />If you don't have a model number, is your trim switch on the port or starboard side of the motor pan?
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

thanks Walker, but I've donned the jewelers glasses and can see what appears to be a metal flap (spring loaded?) inside that flush mounted brass fitting. I'll take pics to clarify this one. Thanks for the fire tip...however, i might just set this one on fire myself before i finish.
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

My model numbers are E150EXEIS and E150NXEIS. Like i said, I can't seem to find them mentioned in my service manual. It does point out the ones with a 5/16 or 3/8 head alluded to earlier on the manifold itself, but nothing about the ones on the powerhead.
 

seahorse5

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Re: 1991 Evinrude 150 powerhead check valves

You have a 60 degree motor according to the image you posted. Your recirculation check valves are on the "plastic" intake manifold, each cylinder has 2 round "discs" at the bottom of each intake bore. The "o-ring" formed seal loops around each one. Don't use compressed air to check them. Use a plastic srynge with a piece of tubing on the tip. You can use Bombardier ( OMC ) Engine Tuner to clean the valves, fittings, and lines.<br /><br />Be sure you use the new tan colored intake gaskets, as the original black ones would swell and cause air leaks, due to chemicals in reformulated fuels.
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

Thanks for replying so fast. I've carefully looked at the intake manifolds and seen the check valves "discs" you described. About the "clogged" brass inserts...how can i clean them out? It feels like a solid metal piece in there. Drill bit perhaps?
 

seahorse5

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Re: 1991 Evinrude 150 powerhead check valves

Use a plastic syringe with a piece of tubing on the tip. You can use Bombardier ( OMC ) Engine Tuner to clean the valves, fittings, and lines.
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

I'm speaking of the ones on the powerhead, as shown in the picture.
 

kgw

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Re: 1991 Evinrude 150 powerhead check valves

okstatefan,<br />the brass fittings on the power head side have very small holes in them a paper clip will not fit. these are press fit in block and can be twisted out whith vise grips,but then you have to buy new ones . do as suggested and see if alcohol will flow through with a syringe.
 

cowboyup

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Re: 1991 Evinrude 150 powerhead check valves

Alcohol works fine on three of them.The other three are missing. I can't find the part number in my parts catalog, or any mention of them in my service manual. Could i put in-line check valves on the recirc lines instead?
 
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