OMC Cobra 2.3L 1987, Outdrive Test On Muffs

[DavidW2009]

This is my first I/O. I'm going thru the engine and outdrive to see if it's any good. The engine has checked out fine. 150 -155 lbs. compression on all cylinders (warm). 55 psi oil pressure (warm). No water in the oil. The engine runs smooth and starts well and idles at 800 RPM in neutral. Engine temp has gone no higher than 150 deg F on muffs. There is a thermostat.

I changed the outdrive oil and added the required 64 ounces. The prop turns freely and smoothly in neutral.

Question: With the engine running on muffs, at idle, is it okay to shift it into forward to test the outdrive for noises, etc.? Then shift back to neutral and let the prop stop spinning, then shift it into reverse, all the while on muffs?
(Also want to see if the ESA works.) Will I hear anything if the outdrive is bad?

I've not tested the drive at all. In neutral it is quiet (if that means anything).


Question #2: Is it okay to check the power steering while on the muffs. turning the wheel back and forth, (of course, making sure the muffs stay on)?

Thanks.

 

[fishinpa]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

Yes you can do those for a general idea of things.
water test is the only real proof.

Just dont go throttle happy on the muffins !

light rev in gear , idle down shift etc.

fish

 

[Don S]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

It doesn't hurt to shift the drive out of the water, might as well see if it works before you hit the water. Same with the steering, just have someone watching to make sure the muffs don't fall off and you burn the impeller up.

 

[Juniinc]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

It is a good sign, if it is quiet in neutral.
Put the drive all the way down.

 

[DavidW2009]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

WOW. Thanks for the replies.

I'll give it a try. (Of course, the drive is all the way down.)

 

[DavidW2009]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

I had a chance to try it (shifting the outdrive) after work today.

Fired it up on the muffs and engaged forward. No problems. Slick as can be. No noises.

Put it in neutral, let the prop stop, shifted into reverse and it stalled. Tried it again and it stalled. Tried forward and no problem.

I then realised I had not let the engine warm up. It was still cold. I let it get up to 120 deg F and tried reverse again. Slick as can be. No grind, No noises. No stall.

I then tried it revving to 1500 RPM in both forward and then reverse. I got out and listened to the outdrive and put my hand on it to see if I could feel any vibration. None. In both forward and reverse, it was smooth and quiet. Maybe the ujoints are still okay (probably need some grease).

I shut the engine off, then restarted it and tried everything again. No problems. The ESA seems to be working fine. I can tell when going into forward, but not so much when going into reverse. Though either direction was slick and smooth effort-wise on the control handle.

I think I may have a good outdrive. But a good lake test is what it really needs. That ain't gonin' ta be any time soon. Maybe next year if I decide to fix the transom.

 

[Lou C]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

Based on what you're reporting...you may have a sticky transom shift cable or build up in the pocket behind the bellcrank both of which can cause stiff shifting....because on the water hose...on land...the ESA should not be engaging...the ESA will engage when you shift from both FWD and REV to neutral when there is a load on the prop (water)...but it should NOT engage when you shift into gear ...if so you can get stalling....I run mine on the water hose and when I shift it to Neutral the ESA does not engage...but in the water it does...about the idle speed....you want to get it lower...it should be set with the engine in FWD in the water with a load on it...between 500-600 rpms...I've got mine idling on land at 600 and with the load of the water on the prop it will probably drop it down to 500 or so...a dog clutch sterndrive shifts better with the lowest idle you can get without stalling...

 

[DavidW2009]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

Based on what you're reporting...you may have a sticky transom shift cable or build up in the pocket behind the bellcrank both of which can cause stiff shifting....because on the water hose...on land...the ESA should not be engaging...the ESA will engage when you shift from both FWD and REV to neutral when there is a load on the prop (water)...but it should NOT engage when you shift into gear ...if so you can get stalling....I run mine on the water hose and when I shift it to Neutral the ESA does not engage...but in the water it does...about the idle speed....you want to get it lower...it should be set with the engine in FWD in the water with a load on it...between 500-600 rpms...I've got mine idling on land at 600 and with the load of the water on the prop it will probably drop it down to 500 or so...a dog clutch sterndrive shifts better with the lowest idle you can get without stalling...

Thanks for the correction. So the hesitation going into forward may be from a sticky cable?

Yes, you are right. The idle needs to be lower. The manual says 600-650 in gear. And I suppose that means in the water, too. I'll drop it down to 650 in neutral and try it again.

See attached photo. Is that the bellcrank you are talking about?

 

[Lou C]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

no those are the switches for the ESA system....the bellcrank you can see when you pull off the drive and look where the shift cable comes out of the pivot housing...deposits often build up behind there in the pocket where the shift cable comes out and if it gets bad enough it can restrict the movement of the bellcrank..

 

[DavidW2009]

Re: OMC Cobra 2.3L 1987, Outdrive Test On Muffs

Pulling the drive will be next. Thanks for the tip. I'll check the bellcrank area.

It also occured to me, the shift cables have not been used (operated) in at least 5 years. I think I saw a procedure on lubing the shift cables here on iboats.. They may be sticky, or not as smooth as possible due to lack of use.

Shift cable operation and adjustment is critical on OMC's, according to what I've read. Don't want to ruin what may be a good drive, just because of poor cable maintenance.

Edit: I compared the ease of operation of the control lever of the OMC with the Quicksilver on my '97 Force. The OMC is smoother and a little less effort.
This was done with the engines running and water. (Of course, comparing an I/O to an O/B is not apples to apples.)