OMC 4.3 cobra shift help.

[JCMINIS]

Must be terrible at searching,I looked and looked but couldnt find what I need help with.Maby someone can point me in the right direction.

I had the shift cable and bellows changed on my cobra OMC.I had a small boat shop(only OMC tech I could find) change the stuff out.Went to the lake this past sunday need help with a couple of issues.I plan to take it back to them but would like to gather a bit more knowledge before I do.

1.When in reverse the part circled clicks and jumps around.



2.When in forward just above idle(in forward motion) rpm's will jump up 800-1000 rpm(guessing) and then runs fine through the rpm range.

Any help would be greatly welcomed.

 

[marada1]

Re: OMC 4.3 cobra shift help.

The part circled is the cam that makes the "shift interrupt switch". It should only move and make the switch when the shift cable is in a bind (when shifting out of gear). When the switch is made it "interrupts" the ignition, causing the engine to stumble, therefore taking torque off of the drive allowing easier shifting. Once out of gear the cable should relax allowing the cam to return to it's neutral position. Item #40 in the diagram is a spring that returns and holds the cam at it's home position. Make sure the spring is in place and doing it's job. The cam should not "jump around" when in reverse or any other time as you described.

 

[JCMINIS]

Re: OMC 4.3 cobra shift help.

Thanks, checked the spring it is intact and seems to be working(when moved by hand).

Anymore before I take it back to the shop ?

 

[Coors]

Re: OMC 4.3 cobra shift help.

http://www.hastings.org/~stuart/cobra/kw-shift.html

this is generic, but will get you started.

I would take it back to the guy.

 

[marada1]

Re: OMC 4.3 cobra shift help.

When you checked for the spring did the cam feel loose? Also, did you move it both directions to confirm it has spring tension both ways?
And yes I would agree that it should go back to the repair shop for adjustments.

 

[Gary H NC]

Re: OMC 4.3 cobra shift help.

If the repair shop knows the exact measurements for the lower shift cable,bell crank adjustments and cable trunnions. unless he is an older tech that was around during all the Cobra headaches he might not have a clue.If he did it should of been right to start with.The drive needs to be pulled and probably a new lower shift cable.

 

[Gary H NC]

Re: OMC 4.3 cobra shift help.

Best investment you will ever make for your Cobra!It has a very detailed shift adjustment section.
http://cgi.ebay.com/ebaymotors/1986...CE-MANUAL_W0QQitemZ200213947894QQcmdZViewItem

 

[Coors]

Re: OMC 4.3 cobra shift help.

Get that manual right now; that is cheap

 

[Coors]

Re: OMC 4.3 cobra shift help.

Best investment you will ever make for your Cobra!It has a very detailed shift adjustment section.
http://cgi.ebay.com/ebaymotors/1986...CE-MANUAL_W0QQitemZ200213947894QQcmdZViewItem

Gary, thought you gave up ebay, after the last burn.

 

[Gary H NC]

Re: OMC 4.3 cobra shift help.

Gary, thought you gave up ebay, after the last burn.

I'll still do searches to help other members..

I have just a hand full of trusted sellers i buy from.
The manual seller is very trustworthy.

 

[JCMINIS]

Re: OMC 4.3 cobra shift help.

Yes it is going back.

I just wanted to "kinda" know what I was talking about when I take it.

Thanks for the help.

 

[Gary H NC]

Re: OMC 4.3 cobra shift help.

Ask the mechanic what service manual he has and what adjustments he will make.
Also look and make sure the lower shift cable is RED!
That was an update from OMC that was critical.The original was a black cable.That does not mean if it is red its not worn out.

 

[JCMINIS]

Re: OMC 4.3 cobra shift help.

Ask the mechanic what service manual he has and what adjustments he will make.
Also look and make sure the lower shift cable is RED!
That was an update from OMC that was critical.The original was a black cable.That does not mean if it is red its not worn out.

Yes its red,I mentioned that I had the shift cable changed in the 1st post.I will check into the manual and ask the tech.

I need to get a manual,but putting it off as I plan to park a new caravelle 237 in its place this fall !!

P.S. thanks for the help !!

 

[Gary H NC]

Re: OMC 4.3 cobra shift help.

I wish i still had my old manual,i could scan and send you the adjustment measurements..
Hopefully the shop will get it right..
Good Luck with it!

 

[Lou C]

Re: OMC 4.3 cobra shift help.

I think that just about all of the adjustment measurements are on the Stuart Hastings website, the pix are a little hard to see clearly but the info is there.