Motor shifting opposite - Need advice

[Numlaar]

Hey all,

OK scenario:

Blew an 83' 175hp evinrude... swapped it out for a 1978 175hp Evinrude, Kept the 83 controls (78' did not come with controls).

Problem:
When I shift the controls into forward, the motor shifts into reverse... at first I thought I had bought a counter-rotation engine by mistake, but swapping out the lowers, it still works the same way...

Further investigation reveals the following:

When moving the controls into forward, it pulls the cable forward... (working like I think it should, and like it did on the 83')
(Throttle works correctly for direction on both engines, its just the shift that I am having problems with).

On the 83' engine, The cable moves forward, and this activates the shift linkage, and moves the shift rod lever UP to shift the lower unit into forward. (Works correctly).
On the 78' engine, The cable moves forward, and this activates the shift linkage, and moves the shift rod lever DOWN to shift it into reverse (it's cantilevered to work opposite of what I need). The action of the shift linkage is opposite.

Picture here:

Additional direct comparison, shows that the shift lever on the 78' is an external 2-piece lever and bolts to the bottom of the block, and that (like I mentioned above), works opposite of what I need it to.
The shift rod lever on the 83' works the correct direction, and is run through a molded assembly at the bottom of the intake manifold.

Picture of later model shift linkage:

I am looking for advice on how to correct this:
1. Can the controls be reversed somehow to cause the cable to move opposite?
2. Is there some sort of external shift rod lever that isn't cantilevered to work opposite, and I can change it out?
3. Do I need to find a set of controls for a 78'?


4. Right now the only solution I can see is to swap out the entire intake manifold from the 83' to the 78', because the 83' has the lever working the way I need it to, but this is a LOT of additional work, and was hoping for a faster solution, also the 83' is internally choked, and the 78' is externally choked, so I am not sure if I can swap out the intakes without additional problems or risk of damage to the engine (not sure what the difference is between internally/externally choked in regards to the passages), at the least I would have to plug all of the ports for the vaccum tubes.

Sorry I just have never seen this particular type of shift rod lever before... (this two piece design).

Any thoughts or suggestions?

 

[metriccrescentwrench]

Re: Motor shifting opposite - Need advice

For a few years OMC made hydraulic shift assist (I think that's what they're called) gearcases. Instead of a clutch dog they have an oil pump that facilitates shifting. That's what you have on your '78, and yes, the shift rod needs to move in the opposite direction for those. (I got an education in these when an unscrupulous ebay seller tried passing off a 1976 lower unit as a mid '80s). Shift rod up = reverse, shift rod down = forward (which is opposite of all the later lower units).

On the 83' engine, this moves the shift rod lever UP to shift the lower unit into forward. (Works correctly).
On the 78' engine, this moves the shift rod lever DOWN to shift it into reverse (it's cantilevered to work opposite of what I need).

Are you sure about this statement? Reason I ask is that, again, the shift rod on the '76 lower unit I had in my possession (while going through the ebay dispute process) had to go down to go into forward. It sounds like probably the shift rod is being moved in the proper direction for a "standard" gearcase (up for forward, down for reverse), I'm pretty sure the controls for those few years pushed the shift cable aft for forward, and pulled it for reverse. Did that make sense?

I'd check to see if your '83 lower unit will work on your '78 engine. Maybe Faztbullet or one of the other experts will chime in. As I recall the driveshaft splines are the same, but I believe you'd have a job on your hands adapting the shift rod to the linkage.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

Are you sure about this statement? Reason I ask is that, again, the shift rod on the '76 lower unit I had in my possession (while going through the ebay dispute process) had to go down to go into forward. It sounds like probably the shift rod is being moved in the proper direction for a "standard" gearcase (up for forward, down for reverse), I'm pretty sure the controls for those few years pushed the shift cable aft for forward, and pulled it for reverse. Did that make sense?

I'd check to see if your '83 lower unit will work on your '78 engine. Maybe Faztbullet or one of the other experts will chime in. As I recall the driveshaft splines are the same, but I believe you'd have a job on your hands adapting the shift rod to the linkage.

Thanks so much for the reply, but to answer your question, yes I am sure... I spenta few hours going back and forth between the two, and I actually swapped the lower units already, and got the exact same result... the 78' I bought was a "piece together" motor, (had a 78' powerhead on a later model mid/lower). It may have had the type of lower unit on it that you are describing, but thats not what's there now... So while what your stating about the shifting "supposed" to be opposite, since I actually do not have one of the special styles of lower units, is not whats happening, and in my case will not work... I need for it to shift like all the later models do, (Up for forward, down for Reverse). right now, with this cantilevered shift linkage, it's doing the opposite of what I need it to do. It seems that the shift linkage on the motor itself is setup for what you are describing (and now I have learned something new, because I thought they all shifted the same way, but see now (obviously), that they dont!

So I am basically stuck with how to correct the situation... I don't have the money or wherewithall to find one of these "special" lower units, especially when I already have two good ones! heheh Just need to figure out how to make this one work the way I need it to.

The solutions I have shown above are all I could come up with for the time being...


/edit also edited original post with better description of the cable action...

Just to be more precise with the info, the shift cable itself moves the shift rod lever in the same direction on both engines..., but on the 78', this causes the lever to shift down, and the 83' for it to shift up, so its all in the lever action, they work opposite of each other... hope that helps, its very difficult to describe!

 

[metriccrescentwrench]

Re: Motor shifting opposite - Need advice

Ahhh. So you've got a '78 powerhead (with the '78 shift linkage) mounted on a later mid section / lower unit.

Hopefully one of the experts will weigh in with a suggestion. Probably the easiest fix would be to get the earlier lower unit and sell one of your other ones, but as you mentioned that's still not ideal.

I don't know if it's something you'd want to consider, but you could always install a separate shifter rigged to move the cable in the desired direction. Here's one similar to what's on my boat http://eddiemarine.com/store/cart.php?m=product_detail&p=14098&c=76 They can be rigged to go in either direction.

 

[Dhadley]

Re: Motor shifting opposite - Need advice

Simply keep the powerhead linkage matched to the lower unit. Early units used the 2 flat rods under the intake with the barrel on the shift rod. Later units used theshift rod that goes thru the bosses on the bottom of the intake. You can use the later intake with an early unit by cutting the bosses off.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

Simply keep the powerhead linkage matched to the lower unit. Early units used the 2 flat rods under the intake with the barrel on the shift rod. Later units used theshift rod that goes thru the bosses on the bottom of the intake. You can use the later intake with an early unit by cutting the bosses off.

That is correct, I currently have the "two-piece" setup with the dowel pin that goes through the shift rod, and throws the wrong way, and need to convert it to the later model style with the bolt that goes through the shift rod...

Soooo it looks like I am going with option #4 and switching the intakes so that I can have the mounting bosses for the late model shifting system....

That leads me to one very important question I had above:

1. Is there going to be any kind of problem in using the internally choked later model intake (with the vacuum/fuel hoses), on the older externally choked engine?
2. Can I just plug the vacuum ports?
3. Will it still flow/perform the same way?

 

[Dhadley]

Re: Motor shifting opposite - Need advice

Not really sure what you mean by internal and external choke but you can run the primer system on either intake.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

Not really sure what you mean by internal and external choke but you can run the primer system on either intake.

The 78' motor has carbs with choke flaps (externally choked), the 83' has the choke system with the vacuum tubes (primer system) (no butterflies in the front of the carbs).
The 78 intake has no ports in it for these vacuum tubes for the primer system, the 83 does, so my concern is, will these additional ports for the vacuum tubes for the primer system be a potential fueling problem if I swap the intakes? (I have blown way too many motors for lean conditions, and do not want to do it again).

 

[Dhadley]

Re: Motor shifting opposite - Need advice

The primer system injects fuel either in the bypass cover or behind the carb into the intake. Injecting into the intake is the better method.

 

[Dhadley]

Re: Motor shifting opposite - Need advice

The recirc lines are not part of the primer system.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

OK this is my question regarding the intake swap:

here's the intake off the 83'

with a closeup of the nipples I am talking about:

You can see that in between the carb mounts, there are these little "ports" that had tubing hooked to them originally as part of the recirc/primer system or whatever you want to call it...

my 78' powerhead does not have any of these...

So my question fo doing the swap is:

1. Do I need to remove these, and install plugs?
2. is there going to be any problem with running this intake on my motor with these holes plugged up?

Just not sure how they effect the fuel flow.

I do not want to switch the entire motor over to the primer/recirc system, because that would involve also changing out all of the side plates, carbs, choke solenoid, etc.

 

[Dhadley]

Re: Motor shifting opposite - Need advice

Those are part of the recirc system and has nothi to do with the primer system. Yes they can be plugged. If you use late model carbs the nipple for the primer will already be in them.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

Awesome! thanks for the info... now just need to find some plugs to fit!

Eventually I may install the recirc system... but like I said, I need to also switch over the exhaust plates that the tubes go to... is there a particular advantage to running this system? (Improved performance, fuel economy?), or is it strictly to reduce emissions?

 

[Dhadley]

Re: Motor shifting opposite - Need advice

They don't go to the exhaust plates. Without them it'll run like an older motor that never had the system. I doubt you'll see the difference.

 

[Numlaar]

Re: Motor shifting opposite - Need advice

They don't go to the exhaust plates. Without them it'll run like an older motor that never had the system. I doubt you'll see the difference.

Hmm ok... the tubes ran from the nipples on the intake, to these individual plates (6-total, 3/side), that seemed like they were part of the exhaust routing, so maybe I am describing it wrong, but anyway, I will go with what you say, and just plug them and hope for the best.

Thanks again for all of your help!

 

[Dhadley]

Re: Motor shifting opposite - Need advice

The early motors had them hosed to the by-pass covers which are over the intake ports. The exhaust is in the center of the back of the block.