1973 85hp control box question

[KStoon]

I am restoring/rebuilding a JC pontoon I bought last year. It has a 1973 85hp Johnson which runs pretty good. I recently installed a tach to monitor the rpm's so I could tell if I need to change props. Well I figured out one thing. I'm crusing across the lake at 2,000 rpm! Further digging revealed the cause. My throttle is only opening about 1/2 way! When I bought the boat the previous owner said that the remote had been replaced. I believe he said it came off of a 1982 engine. I don't know of the engine size it came off of. Doing research on the Evinrude site I determined my remote does resemble the 1982 style. I'm not finding any numbers on my remote so I guess they are not real easy to identify. I have opened up the remote to ensure nothing stupid is going on in there and all appears normal, gummy but normal. I can move the throttle cable and clevis with the box open and get WOT. It appears the cam groove which the throttle follows would not give it enough travel to match the movement needed to get WOT. I guess what I'm longwindedly asking is are remote controls very interchangable? Should I try to find a remote which is the same as this engine came with? Or is it normal to be able to use a remote from another year as long as the engine size is similar? As if you couldn't tell I'm a noob to all this. Any ideas or advice is welcome. Thanks!

 

[emdsapmgr]

Re: 1973 85hp control box question

I would be suprised if OMC changed the travel distance of the throttle cable in the control box from 73 to 82. You may have it out of adjustment back at the engine. The throttle cable is adjustable under the front of the engine cowling. I'd start adjusting there to see if you can get full throttle. If it still does not give you full throttle and normal idle, you may need to check the linkage (sync and link) on the engine itself to make sure it is setup correctly, then re-check the throttle cable adjustment.

 

[kenmyfam]

Re: 1973 85hp control box question

Have you run it on the water with the box open ??
Not over familiar with differing controls but the issue could certainly be at the motor adjustment end.

 

[F_R]

Re: 1973 85hp control box question

Have you run it on the water with the box open ??
Not over familiar with differing controls but the issue could certainly be at the motor adjustment end.

The amount of cable travel has been standardized since way back in the 1950's. At least on OMC and most other motors.

 

[KStoon]

Re: 1973 85hp control box question

I appreciate the fast replies. I have had the engine cover off and examined the linkages and compared them to the service manual. All appear to be correct. My next idea was to attempt to adjust on the throttle cable at the engine end. I didn't want to mess with it untill I had some ideas if the remote was suitable for this engine. I sounds like it might be. No I have not run it with the box open while on the lake. I did follow the cables looking for any movement in them when opening the throttle. I know if the housing is moving instead of the cable inside that can be a problem. I'm not seeing that. I'm an automobile tech and have dealt with cables controlling automatic trans throttle pressure and such and the affect of shortening and lengthing the cables. What this would seem like is that the throttle cable housing needs to be adjusted longer. I'm just proceeding cautiously and trying to learn about what I have before I just tear into it blindly. Having mis-matched pieces concerned me. Thanks so far!

 

[KStoon]

Re: 1973 85hp control box question

This evening once I got home I played with the cable adjustment and worked the throttle to see if I'm making any improvement. Good news! I don't think much adjustment should be made. Here's what I found. While adjusting the cable I finally got the throttle to go wide open! But due to the slopp in the spark lever and the throttle lever (which are stacked on top of one another) my throttle does not go back completely to idle. I returned the adjustment close to where it was so the levers are on the idle stops when returning the throttle to neutral. A little preload on the adjustment helps tighten up the slopp while not really affecting WOT. I think my problem has been in the remote and in the cam/roller/pivot. Like I mentioned the grease is real gummy and I think it was causing a binding which I loosened up some by working the throttle with the cable loose from the engine reducing the effort required to open it all the way up. I'm going to try cleaning the old grease up and getting some lube in there that's not 25 years old! I'll make sure the roller/follower spins freely and the cam and linkages move freely. I guess I'll add spark and throttle lever bushings to my lengthing wishlist to order this winter. Thanks for clearing up the confusion on the control interchangability. I'd love to feel this engine @ WOT pushing a 20' toon accross the lake. 2,000 rpm just doesn't cut it. I'm sure it's not great on the engine either! I'd like to take it out this weekend to see if I'm proped properly so if I'm not I have all winter to find a deal on a better sized prop. I'll update if I do. Once again thanks for the replies!

 

[emdsapmgr]

Re: 1973 85hp control box question

A white teflon type grease (Merc 2-4-C) works well in the control boxes. It does not get as stiff when the temp drops.

 

[KStoon]

Re: 1973 85hp control box question

Thanks for the tip. I will pick up some lube this weekend. I'm not sure what my dealer carries but I bet they have the Merc. lube. I had to scrape some of the old greese out of the cam groove with a screwdriver it was so waxy. The roller on the throttle lever which follows the groove now spins too. Wow! I'm sure the whole throttle movement will not be such a fight once I'm done cleaning and lubing! It was stiff and I felt like I'd break something if I forced it. Buying something this un-maintained always prsents "challanges"! I'm learning alot as I go though. Thanks!