TOPIC: 35HP Johnson Seahorse Throttle Linkage Problem

Hey all,

I've got a '58 35HP Johnson Seahorse with a throttle linkage issue.
The ?pivot? prevents the throttle line from engaging the motor into start mode. I've got a second motor (boat is outfitted with twins) that doesn't have the same problem. I swapped the throttle control over from the "good" motor but it doesn't make a difference. Throttle control from the "bad" motor works fine on the "good" motor. This leads me to believe the issue is the pivot. A previous owner drilled and tapped a thru bolt. Thru bolt in or out doesn't have any effect on function.

Pictures attached.

So, the questions...
1. Has anyone else had this issue with a SeaHorse (or any other make model)?
2. Can anyone point me to a good source for a replacement?

Thanks in advance for any help/thoughts/advice.

Regards,
DecaturBob

www.marineengine.com/parts/vintage-evinrude-johnson/377516/catalog.html?http://www.marineengine.com/parts/vintage-evinrude-johnson/377516/37751600001.htm

I have a 1957 javelin parter that may still have what you need. ???

If you will post on the AOMCI ask a member for a manual one of the member will post it for you as to see what you are needing.

www.aomci.org/cgi-bin/yabb2/YaBB.pl?board=askamember

If I do not have the part then you can post on the Webvertize

www.aomci.org/cgi-bin/yabb2/YaBB.pl?board=Webvertize

There is a Johnson Evinrude board that would be a better place for this post - but I'm not going to move it.

The tower shaft and lever should move freely. Some models had a manual throttle knob at the front left base of the engine. This had a brass shaft with a bevel gear on it to mate with the part in your picture. Not all of them had that, and if yours doesn't, the gear does nothing.

I'd check to see that the manual shift lock-out is engaged or stuck. Did you check to see that the shift lever is in neutral?

The leak pictured in photo #1 is likely due to a bad lower crankshaft seal. You must remove the powerhead to investigate further.

Actually, the leak is the powerhead base gasket, not the lower seal.

As for the throttle issue - if you have a second motor handy to look at, simply compare the two to see where things are hanging up. Unhook the throttle cable from the motor - you've already verified that the issue is not the control box.

That bolt out the side shouldn't be there. If it is all that's holding the tower rod to the gear, then let me know - I have some of the pins that go in the hole in the bottom end of the tower rod. With that in place, things may not be properly aligned.

- Scott

Looks like the plastic piece on the bottom of the tower broke .

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Then someone got it out of adjustment with an " unauthorized " repair.

Thanks for all the replies. Here's a little more info...

Before I get into it - A question about setting up a rig to run the motors in the garage. I know for sure and certain NOT to run the motors without the prop in water. The question: How far do I need to submerge the shaft in water? Cover the prop and then +6 inches? more? less? Just below the expeller hole? There are two motors on the boat and they're rigged for sync-ed steering. I've discovered that trying to tilt them up is impossible with out either 4 people or completely disassembling the steering linkage... so the shallower a bucket I can use the less of a pain it is.

Now back to the original issue. A brief note in case anyone is wondering: All of this investigation has been done without actually trying to start the motor. I've already done that on the lake enough to know it's not going to start until I get this linkage problem fixed .

I do have a second motor for comparison. The throttle cable from the 'bad' motor works just fine on the 'good' motor. And, as one might expect, the throttle cable from the 'good' motor doesn't work on the 'bad' motor.

I've observed that, when trying to engage the throttle to start position, the throttle cable rides up on the gear and won't push past it to fully engage. On the 'good' motor, the throttle cable comes to rest a micron off to the side of the gear when fully engaged.

Also observed that the gear teeth on the 'bad' motor are smaller than those on the 'good' motor. Could be the one on the 'bad' motor is not the correct part for the model...

BG wrote: "I'd check to see that the manual shift lock-out is engaged or stuck. Did you check to see that the shift lever is in neutral?" Yup, I checked it. Tried manually engaging to start position with shifter in all three positions. There's something off there as well. It engages in all 3 positions - SCARY!

I agree that previous repairs have put the assembly out of alignment. What can't be seen in the photo is that the pin on the back side of the shaft is broken. Someone attempted repair by drilling a thru hole in the shaft and gear collar and inserting a bolt to secure everything.

The bolt sticking out the side was inserted to replace one previously in place, that I removed (and subsequently lost...) It doesn't come in contact with any part of the motor when the throttle is manually engaged so, other than the fact that it should have never been put in, I don't think it's having an impact.

The more I looked at it and compared to the other motor, the more I came to believe that it was hopelessly fubar (is that a redundancy?). So I've got a new shaft, gear, bushing and pin on the way (I think I ordered a new gasket for the head to).

Parts should be here tomorrow or Wednesday. I'll post again after I've installed with results.

And...having typed all that, and ordered parts, I'm realizing what I didn't do, and should have done, was to take the shaft and gear off the 'good' motor and put them on the 'bad' motor. Dang it.

Cheers to all!

Bruce,

Thanks for the heads up on the JEGO forum. I'll look to post motor questions there first.

Cheers,
DecaturBob

In order to run the motors in your garage, know that the water pump housing needs to be submerged. Water pump is NOT self priming. I would go a couple inches above the housing for insurance. May not be what you wanted to hear, but don't want you to fry a motor.

As a clarification - the water level should be ABOVE the bulge at the seam between the lower unit and exhaust housing.

Also, regardless of whether it pumps water or not when you test it, DO install new impellers in both motors, unless you know they have been done recently.

- Scott

I use a plastic broll and tip traier all the way down it front and tip broll under the motor then fill it almost all the way up. Tip traile up to leavel. Once the motor starts running its going to spit water out ovee the edge. when done shophen the water out.
Mike aka pathfinderz1

Thanks again for all the advice and tips.

Here's the latest report:

The throttle parts arrived and I got them installed this past Saturday. I am pleased to say that the mechanical issue seems to be resolved. The throttle will now push the armature into start position. Still had to grind a shallow bevel into the shifter arm to make it work. I couldn't see any adjustment mechanism that would back it off. I haven't tested the motor yet for 2 reasons - still have the oil leak to deal with and haven't set up test tubs.

When I ordered the parts for the throttle I also ordered a new gasket for the lower unit. I want to spend some time with the manual and looking at the motor before attempting the replacement.

I'll post again as soon as there's progress, or other less fortunate news...

On another topic - same motors: Does anyone have a good source/contact for replacement props and related assemblies for these motors? I've done some on-line looking but can't determine a good shop/store to contact.

Best,
DecaturBob

For used parts go here
www.aomci.org/cgi-bin/yabb2/YaBB.pl?board=Webvertize
Post what you need or look through the site page and see if anybody is selling what you might need.
Mike aka pathfinderez1

Unhook the throttle cable from the motor - you've already verified that the issue is not the control box,if you have a second motor handy to look at, simply compare the two to see where things are hanging up......

There should be NO NEED to do any grinding.

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Adjustments are there.

Hi to all,
Here's the update on my '58 Seahorse...

Previously I posted that I had fixed the throttle linkage problem. Still the case but as yet untested with a live run.

Having thought and pondered about it for a couple of weeks, I decided I was tired of being afraid of the motor and of not knowing what was going on "in there".

So, with repair/maintenance manual and camera at hand I took of the lower unit. The oil drained clean so far as I could tell. Thinking about running it through a coffee filter to see if there is any metal particulate in it. Some of the included pictures will explain why.

There were a couple of bolts with nearly stripped driver slots that I thought would bring my adventure to a halt for the day. Turns out the best tool in my arsenal was part of 1940's vintage ratchet set I inherited from my maternal grandfather (Thanks Grandpa!). That issue resolved, the rest of the disassembly went fairly smooth.

The rest of the story is in the attached and annotated pictures. Any thoughts, advice, experience, etc... are most welcome.

I figure that once I've conquered the first motor, I'll attack the second one.

Credit for the Parts Blowup Image goes to MarineEngine.Com

Best and Happy Boating,
Rob

The snap ring in the picture looks correct.

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Take a careful look at it.

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It has a flat side and a tapered side.

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The groove has a tapered and a flat side as well.

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No those loose bearings will fall out they do not have a cage !!----The loose bearings that fell out can be re-installed using needle bearing assembly grease.

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Believe it or not--You are looking at a lower unit that appears to be in " like new condition " even though it is a few years old.

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A testament to fine manufacturing and maintenance.

The "metal tear", not an issue. Water gets trapped in some of the casting bits under the water pump plate and when it freezes, pops the thinnest casting. As long as the outer perimeter is in good shape, it'll pump just fine, and as long as the upper main seal area is in good shape, it'll hold oil.

The oil in the cavity where the shift rod goes - not sure what it is. Could be unburned fuel/oil, not uncommon with an old 2-stroke. Could be lower unit oil, leaking from the shift rod. While you've got it apart, you should replace the shift rod o-ring. Requires either borrowing or making a shouldered tool to knock the brass bushing out. The o-ring is under that. A local dealer should have the tool and you might be able to bribe the mech to knock it out for you...

- Scott

Update on 35hp SeaHorse rebuild -

I think I've finally got all of the gaskets, seals, rings, washers and "goops" I need to put this motor back together but I need a piece of advice.

Do I need gasket seal for the gasket shown in the attached picture? Chinewalker indentified earlier as the 'powerhead base gasket'. I looked in multiple forums and have seen pretty much 50-50 advice in both directions - 50% Yes use gasket seal / 50% No, don't. Most of the "don't" say the gasket should be self sealing and gasket seal will just screw that up.

As always advice and wisdom always appreciated

Thanks,
DecaturBob

No sealer needed if the surfaces are true and not warped and the new gasket is not all dried out.

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But you may want to use a thin / thin smear around water passages.

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Now you have some more advice.

I always grease my gaskets when applying them by rubbing a light grease over both sides of the gasket. This helps them stay in place, and also helps future mechs disassemble if needed...

Thanks to you both for the tips and advice. Just finished getting all the major components back together. Next weekend will be putting the kibble back on and maybe a tank test on Sunday.

Cheers,
Rob

Here's the latest update and yet another question...

I've got everything back together and just need to charge the battery and get some fresh gas...and double check that the electrics are all tied in on the right points.

Funny thing about refilling the lower unit with oil... If you're not paying attention and pull the wrong the screw, all of the oil ends up in your drip bucket. -- Yup, got distracted and pulled the bow most screw holding the bottom gear housing on instead of the oil drain plug. DOH! You just can't pump oil in there.

And now...Here's the question:
Can I do a tank test without a prop on the motor as long as I don't put the motor in gear?

Both the hubs on my existing props are bad and won't hold up to much torque. I've got a couple of leads on new/rebuilt props and can wait to test the motors if I need. But, if I can go ahead and test the motors without props I'd like to.

I swear I'm gonna put this boat on the water this summer if I have to dig a pond in the backyard for it .

Cheers,
Rob

Finally tank tested the motors this weekend.They fired right up, are a little smokey and don't like low idle. No cataclismic explosions so I consider it a good weekend!

The rods coming off the front of the motors are taped to the choke knob...in case anyone was wondering.

Discovered the body of my Rigid brand shopvac made a great test tank.

I think we're going to the lake next week.

Here's a link to the tank test video: