OMC Cobra freshen up

[Don't Panic!]

ok so I see here: http://www.hastings.org/~stuart/cobra/sb4052_5.jpg that I used the adjustment procedures for the shift arm shown in pic 18, but I have the shift arm shown in pic 19. So I guess I need to find the correct cable installation instructions for my setup.

 

[Don't Panic!]

welp. It appears that of the two adjustment procedures on Midnight Wolf's website, I just picked the wrong one to follow... Reading http://www.midnight-wolf.com/OMC_Cobra_Shift_Cable_Adjustment1.pdf it looks like that is the correct procedure for my cable setup.

I may have a little time after work today, but most likely this will have to wait till next weekend.

 

[Lou C]

OK one thing I did not see you do:
1) did you measure the shift rod height when the drive was off? If this is wrong, you will have problems, but once set right it does not change
2) you may be correct, there were 2 different design engine shifter bell cranks and that caused confusion. Look again at Midnight Wolf's instructions, I think he covers both styles.
3) if you totally disconnect the remote cable, can you shift it using that engine shifter bell crank (make sure you get a helper to spin the prop) from neutral to FWD and REV. Spinning the prop is necessary for the clutch dogs to line up. When you do this, will the load lever re-center with the ESA trigger lever? If not, then something is holding pressure against the transom shift cable. If the shift rod height adjustment on the drive was way off it could cause that.

What I did on mine:
1st set shift rod height when drive was off.
then did transom shift cable adjustment, then installed drive.
next used shift cable tool to adjust where the trunnion (mine was the adjustable kind) for the shift cable was the correct distance from the anchor point on the cable attachment point. I think it was like 6 1/2" but it was six years ago so I have to dig up the tool and measure.

Then with a helper to spin prop, used the transom shift cable (now just retained by the trunnion in the load lever, not hooked up yet to the bell crank on the engine) to shift from neutral to fwd and rev. I took a sharpie and made a mark on the cable where neutral, fwd and rev were and measured to make sure I got equal stroke on each side of neutral, very important. At the same time you helper can feel if its locking into each gear or not. Start with this and report back.

 

[Lou C]

Yep I think #1 is the one you need. But do what I said above too first.

 

[Lou C]

Here's some pix of mine shifted into fwd and rev.....top pic is fwd bottom is rev
ESA trigger is centered in both, can't see it in the top pic.

 

[Don't Panic!]

OK one thing I did not see you do:
1) did you measure the shift rod height when the drive was off? If this is wrong, you will have problems, but once set right it does not change

I did not. I had intended to, but it appeared that I'd need to separate the upper from the lower unit to do so which I did not want to do since everything so far had been looking better than I'd expected. It shifted OK before, so I figured this was probably alright. A visual when installing the outdrive showed the bellcrank dead center in the V when sliding together.

3) if you totally disconnect the remote cable, can you shift it using that engine shifter bell crank (make sure you get a helper to spin the prop) from neutral to FWD and REV. Spinning the prop is necessary for the clutch dogs to line up. When you do this, will the load lever re-center with the ESA trigger lever?

I believe it does. I'll have to verify because I don't remember 100%. I tried and checked so many things lol.

What I did on mine:
1st set shift rod height when drive was off.
then did transom shift cable adjustment, then installed drive.
next used shift cable tool to adjust where the trunnion (mine was the adjustable kind) for the shift cable was the correct distance from the anchor point on the cable attachment point. I think it was like 6 1/2" but it was six years ago so I have to dig up the tool and measure.

Then with a helper to spin prop, used the transom shift cable (now just retained by the trunnion in the load lever, not hooked up yet to the bell crank on the engine) to shift from neutral to fwd and rev. I took a sharpie and made a mark on the cable where neutral, fwd and rev were and measured to make sure I got equal stroke on each side of neutral, very important. At the same time you helper can feel if its locking into each gear or not. Start with this and report back.

Will do. One thing I don't like about the Midnight Wolf instructions for the style bracket I have is that on step 16/17 it has you adjust the trunnion on the transom cable to fit into the holder. Doesn't this defeat the whole point of using the special tool?

http://www.midnight-wolf.com/OMC_Cobra_Shift_Cable_Adjustment1.pdf

 

[Lou C]

It does seem that way, and it may be that those instructions were written before the tool was available. I know for sure in my 1988 OMC shop manual there is no mention of the tool. If you tried using the tool and feel you did everything else right and it the load lever still trips the ESA trigger then try doing it that way (instructions) set the load lever centered and adjust the trunnion till it fits in and see if that gets you where you need to be. Doesn't make sense but it may work!

 

[Don't Panic!]

I've been thinking (dangerous) about the setup procedure a bit, What is the significance of the 7 9/16" number from the shift pin hole to the end of the brass housing on the transom cable? Seems irrelevant to me, as long as the pin to trunnion is correct, the distance to the housing is of no importance since it's not being held by anything. Am I wrong on that?

other than setting it roughly in the neighborhood so you can achieve the 6 1/2" from trunnion to cable end, I can't see how it matters what that dimension is.

And with the directions I'm going to be using, even the 6 1/2" is approximate, to be set during setup. Honestly I'm not seeing any reason to have even bought or used the special cable alignment tools. Eyeball 90 degrees, get it close to 7.5", install drive then set the final trunnion to end distance when installing.

Anyway, I guess I'll know more when I actually figure it all out and get it right...

 

[Don't Panic!]

I got a few hours in the garage last night. On the plus side, I totally understand the intent of the shifting system and how it needs to be set up. On the downside, I just can't get it set up in a way that the ESA cut off switch roller returns to center all the time.

I've verified I'm getting full and equal cable throw in F and R on the remote shift cable. I've verified the transom cable is getting full throw in both directions as well, with full engagement of the outdrive gears.

Reverse seems to work perfectly as intended. As the throttle handle is advanced, the roller goes up the ramp and depresses the cutoff, but returns to center once the drive is engaged.

Forward not so much. The roller stays up on the ramp. I don't see this causing an actual engine issue, as the overthrow switch engages correctly and will override the cutoff. A light push on either the cable or the actual rocker assembly will center the roller nicely, I almost wonder if the engine vibration alone will be enough to help it into place. (all my testing has been engine off).

I am wondering if it will function differently/better when actually in the water with resistance. I'm hoping to go for a quick cruise this weekend and test it out.

 

[Don't Panic!]

I did get out for a ride on Sunday, just a quick 30 minute splash up and down the local river. It shifted very well, yay! I ran a bit with the engine cover off and could see the interrupter correctly centering after going into gear.

OK, on to the manifolds...

 

[Lou C]

Great! I was going to take some vids of mine shifting with the hatch open so you could see but since no one goes on the boat with me (too busy) no vids yet. Mine will shift out of gear with just one finger on the remote tried it again. If you are converting from the old bat wings you saw my conversion? I used Barr Marine (cast in USA) manifold and elbow kit (includes the gaskets, bolts etc) and used the Volvo Penta exhaust hoses, clamps and 90* exhaust pipes that adapt from the 4" elbow opening to the 3.5" OMC Y pipe. It all fits perfect. There is a GLM kit that is cheaper, but be careful with those, in the past there were problems with leaks from the joint but that may be solved now. My way of doing it is expensive due to the use of V/P OE parts (those exhaust pipes are $200 each!) but in salt water you want the best quality. In fresh water the GLM kit may work, also HGE also makes a kit for these, I think they use Merc manifolds and elbows.

 

[Don't Panic!]

I believe it's a freshwater boat, but I'll be doing some saltwater with it. Honestly I'm trying to decide what to do, it is not really the long term boat I want, but the boat that presented itself to me... so I'm hesitant to drop a few grand into it but it might be worth it if I can get a few years of use out of it and use that time to really refine what I want in a boat.

the classic dilemma lol.

 

[Lou C]

You can just pick up a set of exhaust manifold gaskets (for any Chevy 4.3, the manifold to head exhaust gasket), don't have to be marine) take em off and check em. If they look good, I ran 2 sets for approx. 6 seasons in salt water each with no trouble. If the 4 outlets in the elbow section are not clogged and there isn't flaking rust inside, I would say they are OK. Do the acetone test to check for leaks. Mine never leaked replacing them at those intervals in 100% salt. Other thing is if you trailer the boat, and flush they will last longer than what I got from them.

 

[PITBoat]

Mine will shift out of gear with just one finger on the remote tried it again.

Man, wish I could be so fortunate with mine...

We had it out briefly this weekend in 40s temps, and I left it in gear for the first time after recovering it to the trailer, so I could winch it myself and no one else have to step into the cold water. It was HARD to get out of gear after that. I mighta shoulda tried revving it a tad, letting it settle, and then pulling back after I saw how hard it was, but I just forced it back into neutral. No fun.

I've winterized it again, so I'm probably done for the year. Maybe I'll have another go at those adjustments in the spring.

 

[Lou C]

Its great when they shift well. I guess I was lucky with mine, I still have the same cable on it as when I bought it in 2002! I pulled mine out on a nice 65* day here in Long Island this Monday (have it moored on a salt water mooring), to do it myself I just drive it up as far as I can on the trailer and then loop a bow line around the winch post to hold it from rolling back (roller trailer) then shift to neutral, turn off and trim up. Then I climb over the bow and winch it up the rest of the way. Do the same thing with the bow line when launching to take the tension off the winch

 

[Don't Panic!]

Wish I had thought to take a few pictures on the water, all I have is this one as I was walking down after parking the truck. Easy ramp, I just dead launched and un-launched (motor off, walk boat on, winch up). It was SUPER windy when coming back in, wind one way and current the opposite, made for tricky docking and the boat almost got away from us when getting it on the trailer.

 

[Lou C]

That's a really nice ramp! We have ones like that at the town ramp the one in my pic above is literally in my backyard. Private beach association, North Shore Long Island. This one has no dock next to it due to the tidal swings (approx. 8 feet every 6 hrs). The boat has lived on a mooring 6 months of the year, for approx. 15 seasons....