1955 25Hp Big Twin....

[Solomon_Man]

All,
I have been working on this little project a while....basically this was a parts motor originally from someone prior and I have verified compression etc is good and the goal is to make it a electric start and tiller.

I found a 1956 donor BigTwin 25hp at a local salvage marina that looks like it took a fall sometime in its life. I was able to get a flywheel and I have a starter/bracket already.

I located the lower unit....in my garage all this time...go figure ....so thats all set as originally I did not have a lower unit.

While I was doing the starter converion and adding the lower unit....I gave it new poins,coils,wires,plugs, carb rebuild and impellor.

Unfortunatelly I am trying to figure out the tiller....Looking in the salvage marina...they have more then a few.. many in bins etc. How does one pick out the big twin tillers specifically 1950's. We did find one that was from a big twin (looked earlier) but the additional shaft (not handle shaft assembly) had a large pulley and cable attached to it (at least what we could see as the cowl was stubborn and it was 20 minutes past closing on a Saturday). If this is usable at all please let me know. (ie pulley can be removed or swapped out)

Also If someone off hand would know the thread size of the flywheel bolt on my 1955 25Hp Big Twin please pass it along. The original one was not there as someone (prior owner) salvaged coils and it was lost. I thought I had a match but unfortunately I do not...

Again thanks for the help,
Chris

 

[kfa4303]

Re: 1955 25Hp Big Twin....

Hi solomon. Here are the parts catalogs for the motor in question. You should be able to look up the part numbers for the tillers. You can probably find the tillers themselves on ebay, or by placing a WTB ad on aomci.org. The bolt needed to remove the flywheel should be 1/4" x 20 x 3'. Be sure you use GRADE 8 bolts and washers. Regular bolts that come with the flywheel puller are not strong enough and may break. Use link below for pics on how to remove flywheel. Holler if you get stuck.

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/376368/37636800001.htm ('55 25 hp) (I don't think they made a 20 hp in '56???)

http://www.duckworksmagazine.com/06/columns/max/index6.htm (great all around link)

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

http://www.duckworksmagazine.com/03/columns/max/04/part1.htm

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm

 

[HighTrim]

Re: 1955 25Hp Big Twin....

The tiller you found was for an early Big Twin. The tillers were the same on many models for many years. The main differences were the colour of course and the grip, if you are not a purist they will work. The early models used a stamped coupling gear while the later models were cast. These cannot be interchanged, UNLESS you get the motor side gear with it. Post a wanted ad at aomci.org as stated in the webvertize section, there are a couple fellows in the club that have hundreds of tillers for sale, I believe they charge about 25 bucks per tiller?, but dont quote me on that.

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

The tiller you found was for an early Big Twin. The tillers were the same on many models for many years. The main differences were the colour of course and the grip, if you are not a purist they will work. The early models used a stamped coupling gear while the later models were cast. These cannot be interchanged, UNLESS you get the motor side gear with it. Post a wanted ad at aomci.org as stated in the webvertize section, there are a couple fellows in the club that have hundreds of tillers for sale, I believe they charge about 25 bucks per tiller?, but dont quote me on that.

High Trim,
I posted for a tiller on aomci.org.

I am heading out to the marina again for a few other minor parts tomorrow, might pick up that Fleetwin 7.5hp
as well and was curious about that early big twin I saw out in the marina...just for knowledge....

I am trying to understand the difference on the early big twins... there appeared to be cabling involved.

From what I read, I expect that there will be no cabling involved on my 1955....?

Basically what I believe I need is the tiller handle the shaft and gear thats inside the tiller handle as well as another shaft that has two gears (one on each end). Also the large attaching bolt etc. Is this correct?

On that older big twin, the cabling had to be involved which must have shifted the armature plate affecting timing/carburation....Do you know if I am correct on this assumption? (curiousity)

I would like to find the era correct tiller but more important is to get things working at this point. I have read online that this tiller assembly approach was used into the 1970s...So will a 1960's/70's ~same HP tiller bolt up? Is there any difference between the Johnsons/Evinrudes for Tillers?

I think the tiller may have been right in front of me all along

Thanks,
Chris

 

[oldybutagoody]

Re: 1955 25Hp Big Twin....

One more great Max Wawrzyniak article from duckworks.com that should help
http://www.duckworksmagazine.com/04/s/columns/max/19/index.cfm

High Trim,
I posted for a tiller on aomci.org.

I am heading out to the marina again for a few other minor parts tomorrow, might pick up that Fleetwin 7.5hp
as well and was curious about that early big twin I saw out in the marina...just for knowledge....

I am trying to understand the difference on the early big twins... there appeared to be cabling involved.

From what I read, I expect that there will be no cabling involved on my 1955....?

Basically what I believe I need is the tiller handle the shaft and gear thats inside the tiller handle as well as another shaft that has two gears (one on each end). Also the large attaching bolt etc. Is this correct?

On that older big twin, the cabling had to be involved which must have shifted the armature plate affecting timing/carburation....Do you know if I am correct on this assumption? (curiousity)

I would like to find the era correct tiller but more important is to get things working at this point. I have read online that this tiller assembly approach was used into the 1970s...So will a 1960's/70's ~same HP tiller bolt up? Is there any difference between the Johnsons/Evinrudes for Tillers?

I think the tiller may have been right in front of me all along

Thanks,
Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

One more great Max Wawrzyniak article from duckworks.com that should help
http://www.duckworksmagazine.com/04/s/columns/max/19/index.cfm

Thanks for the additional link..it answered the remaining questions...

Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

Just Thought of another question....
What is the torque specs for the lower unit bolts (six smaller and one larger bolt). The bolts that connect the lower unit to the rest of the outboard.

Thanks,
Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

All,
Went out to my local salvage marina....Are these all over the United States...or am I just a lucky to live near the Great Lakes..?

Kinda like a old pick a part automotive yard but all marine stuff....

Anyways picked up a tiller....not the perfect example but I think it will work....Actually hard to locate as most were removed already....found one in a large outbuilding...after about a hour worth of diggin. One of the cog gears had many teeth sheared off so I had to get another set of Cog gears. After some swearing and some heat I was able to get the old pins out without damaging anything. Will get those pins around lunch time. Hope to put it on tonight and give the outboard a tank test.

While I was out there picked up a a bunch of misc pieces that over the years my old outboards needed. Two my outboards experienced a couple "falls" in there lives. I also noticed on my Big Twin, I am working on, that the muffle cooling shroud (where water goes through) had a puncture wound (through). It was from the outside going in. That went with the few broken leakage for the manual pull lock assembly etc. So I nice basket/box of stuff.

Also ended up picking up a 1954 Fleetwin as well.

Thanks all for the help,
Chris

 

[HighTrim]

Re: 1955 25Hp Big Twin....

Sounds like fun diggin!

Dont bother with a torque wrench on the lu bolts, just tighten em up with a socket and wrench.

 

[oldybutagoody]

Re: 1955 25Hp Big Twin....

Hildabrands Marine by chance? I think we're just lucky. That place is amazing.
http://www.outboardjunkyard.com/snowmobile-cylinders.html#/ABOUT-US-02-04/

All,
Went out to my local salvage marina....Are these all over the United States...or am I just a lucky to live near the Great Lakes..?

Kinda like a old pick a part automotive yard but all marine stuff....

Anyways picked up a tiller....not the perfect example but I think it will work....Actually hard to locate as most were removed already....found one in a large outbuilding...after about a hour worth of diggin. One of the cog gears had many teeth sheared off so I had to get another set of Cog gears. After some swearing and some heat I was able to get the old pins out without damaging anything. Will get those pins around lunch time. Hope to put it on tonight and give the outboard a tank test.

While I was out there picked up a a bunch of misc pieces that over the years my old outboards needed. Two my outboards experienced a couple "falls" in there lives. I also noticed on my Big Twin, I am working on, that the muffle cooling shroud (where water goes through) had a puncture wound (through). It was from the outside going in. That went with the few broken leakage for the manual pull lock assembly etc. So I nice basket/box of stuff.

Also ended up picking up a 1954 Fleetwin as well.

Thanks all for the help,
Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

Nope,
was not Hildabrands Marine....

Anyways, went to fire things up today on the 25Hp and it kicked right over and the tiller seemed to work properly but I noticed no water pumpin so I shut it down.

So I took the outboard lower unit off and checked my work everything looked like it should work and reassembled.

The impellor is new, the shaft pin is there, blew out the tube and air came out the exhaust port as expected, pushed some water through with a hose... so its clear. The vertical large driveshaft rod engages the engine and rotates with engine when flywheel is turned and is solid. and the lower unit responds similar when all hooked up. Removed side cover of Lower unit and confirm passageway is clear in lower unit as well.

One thing I am not sure of is what year the lower unit is exactly. It bolts up and looks to be correct. I bought a impellor for that year and model, not sure if that is somehow the issue. It looks like the correct one. I have replace 3 others in my outboards and it fit and assembled like the others.

Anyone have any ideas?

Hope to try and fire it up again after work.

Thanks,
Chris

 

[HighTrim]

Re: 1955 25Hp Big Twin....

Are you running in a barrel? Is the water line high enough? Needs to be just beneath the exhaust outlet.

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

Are you running in a barrel? Is the water line high enough? Needs to be just beneath the exhaust outlet.

High Trim,
Yes, I am running it in a barrel....actually a garbage can...Its on a stand and the can fits in between the stand legs/wheels...actually had to use a different garbage can today as the old one is out for trash pick today....

Need to find a old food barrel that I can use for this purpose....I would like to see some of the setups people use to get good ideas.

You may be on to something here.....I noticed that this outboard was much more difficult to get into the bucket. The water line is just a little bit higher then the lower unit connection. I am going to switch to another barrel....I am almost 100% postive that your correct on the problem.

The outboard ran for less then 15 seconds before I shut her down.

A rookie mistake I hope....This thing hasn't ran in at least 15yrs....good to hear something for all that time in my families posession and nothing being done with it.....especially considering it was thought to be a parts outboard.

Keep you all posted on the Big Twin Conversion.....tonight attempt 2.

Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

All,
No dice.....On the second attempt but I have not ruled out the barrel being the issue or not...

Basically got another garbage can thats a little higher (1-2 inch) and raised the can on a 4 wheel dolley (3-4 inch). I was for sure over the waterpump by a few inches. Fired it up and watched for water and nothing but the typical exhaust.

I decided to take it apart again and walk through the lower unit waterpump houseing, confirmed mesh scoop, the lower unit passages and all can be seen thru and are clear. I confirmed the impellor is contained properly engaged to the drivesahaft.

I would like to clamp a hose to the copper pickup tube and see if water just pours out of the exhaust port. I did put a hose on the copper pickup tube but did not clamp it down and water did flow through the exhaust port (most leaked around connection) but if it was clamped then flow would be strong visible and more then likely cleansing.

I went through everything in my manual as well. The only thing I did not see in my outboard is the O-ring that sit on top of the driveshaft. Can someone chime in on what it actually does?

I am considering the purchase of a large barrel....ok getting one....the thing is I just scrapped one I had two weeks ago...damn.

There is a guy not to far away that sells barrels that contain soap and food materials...so should be easy to get one.

Please correct me if I am wrong but the cooling system works like this;

water is around the lower unit at a minimum a few inches above waterpump very close to exhaust port
Water is picked up through the mesh scoop by the centrifical force of the water pump. The pump has passages that direct the water through a copper tube up to the engine. (not exactly sure how the copper pipe attaches to engine but a diagram I saw looked like a compression fitting end that engine sat upon). Anyways the pressure from the pump is pushing the water through the cylinder jackets/Exhaust jacket etc. Then out the exhaust port.

Please correct me if I am wrong....it is safe to say that a good seal before the pump is ideal but after the pump is not as crucial (assuming the seal is not loosing the total output of waterpump).

With the above in mind the biggest culprit is still somehow I am not getting enough water up to/surrounding waterpump.

Is it possible that the engine jackets are clogged or the point of entry to the engine is clogged?

What i am having some issue understanding is if the garbage can is not a high enough waterline then how did I test three other outboards without any issue? A 18, 30, 35 Hp 1950's Johnson/Evinrudes....Not doubting this is the issue but more like amazed by the difference.

Is there anything else that could cause me not to pull water through the outboard?

I am considering pulling one of my other outboard lower units and see if it pumps in this outboard. The other have all pumped without issue.

Also upon all disassembly, the impellor looks fine...so we are not tearing it up in any way.

Thanks for all the help,
Chris

 

[HighTrim]

Re: 1955 25Hp Big Twin....

The o ring is critical, it prevents water from "climbing" the driveshaft and entering the powerhead. Always install a new one, and grease the splines.

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

The o ring is critical, it prevents water from "climbing" the driveshaft and entering the powerhead. Always install a new one, and grease the splines.

High Trim,
Would this o-ring prevent it from pumping?

I think my plan of attack is going to be;

1) Get a barrel (55 gallon)
2) Connect hose (clamp it) to copper pickup and pump water through it a while. (Confirm top end is not somehow clogged)
3) Get the o-ring replaced.

Try it again....If no dice...

4) put on another lower unit.

Thanks,
Chris

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

High Trim,
One quick thing, may may sound like another dumb question, is this o-ring a standard run of the mill o-ring from a hardware store or is it something special....If its special where can I get it?

Thanks,
Chris

 

[oldybutagoody]

Re: 1955 25Hp Big Twin....

Solomon_Man, the o-ring can be had at marinengines.com but unfortunately they have a minimum $10 order and you'll pay shipping, if you can tack it on to a larger order it would make sense but it'll be mighty expensive if all you order is a few o-rings. heres a link to the part. http://www.marineengine.com/newparts/part_details.php?pnum=SIE18-7134&ptype=&Engine=&Model=
The o-ring itself wouldn't cause you engine not to pump but you do need it. it goes in the groove that is just below the splines on the drive shaft that go into the crank shaft of the powerhead.
The things I think might cause your no pump problem are: 1. Missing or sheared pin that goes in the drive shaft and engages the impeller. 2. The tube that goes from the pump cap to the top of the leg isn't seated properly on both ends. 3. Bad or missing rubber grommets on either end of that tube. 4. I think your '55 doesn't have a thermostat but if it does, they can cause flow issues.

High Trim,
One quick thing, may may sound like another dumb question, is this o-ring a standard run of the mill o-ring from a hardware store or is it something special....If its special where can I get it?

Thanks,
Chris

 

[HighTrim]

Re: 1955 25Hp Big Twin....

Go to your local Bearing/Oil Seal supplier, or hardware store armed with the old o ring, and just match it up. It is nothing fancy. I buy them in bags of 100 for each size HP motor, but I restore alot of motors in a year.

Before you install the lower unit, submerge it in a barrel of water, and hook a drill up to the driveshaft. Does it shoot water out of the water line? This will quickly isolate your problem to your gearcase OR your motor.

Let me know what you find.

 

[Solomon_Man]

Re: 1955 25Hp Big Twin....

All,
Thanks for the information and Help!

The outboard does not have a thermostat.

I will try the suggestions and replace the o-ring. I have an o-rings assortment I bought a while back.

I am very interested to see what the actual issue is...

Thanks,
Chris