Tillotson Carburetors - Leaky Bowls

[JasonAych]

I have a 1939 Evinrude Elto Handitwin with a Tillotson carburetor. The kind where there is a chunk of cork with the needle valve through the center and sticks out the top.

I am trying to determine if my carb is as good as it gets or I might expect better results with a different carburetor. Basically it only leaks after sitting not running for a while. Even then it is only a seep. However, it will run indefinately without leaking or flooding the engine out as I found out the past weekend.

I figure that is why the fuel shut of valve at the tank is there. I have always been in the practice of shutting the fuel valve off and running my engines dry.

I have replaced the cork float with new cork sealed with Seal-all. I test floated it in a container of fuel for buoyancy.

 

[1946Zephyr]

Re: Tillotson Carburetors - Leaky Bowls

Do you know what ELTO stands for? Evinrude Light Twin Outboard. Pretty cool huh. Yea, Ole Evinrude left his own company for a while, back in the 20's I believe and started his own line of motors. Then he went back to Evinrude (OMC) corp. Odd how things work. Him and his wife passed away in the 30's and his son Ralph took over the company. In 1936, just after his son took over the company, they acquired Johnson.

Tillotson carbs were commonly used on Evinrude (and ELTO) motors up into the early 50's The latest I saw was on a 1951 Fastwin and Fleetwin.

The old cork floats were noted for getting soaked with gas and loosing bouyancy, therefore flooding the engines out. Often times people re-shellaced them to minimized that problem. Finding a plastic float to match your old one is ideal, but not likely. Someone here may know of better stuff to coat your cork with, but I don't.

 

[tx1961whaler]

Re: Tillotson Carburetors - Leaky Bowls

I re-coat mine with model airplane fuel proof "dope", but I still run the carb out after use.
Shellac is alcohol soluble.

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

I have replaced the cork float with new cork sealed with Seal-all. I test floated it in a container of fuel for buoyancy.

I really do appreciate you trying to help me out but, the reponses do not really answer the question I was after. As I already stated I sealed the float. I have no doubt that the Seal-All will work, I tested it. I am unaware of anybody that makes a non-cork float for this type of carb.

I am trying to determine if my carb is as good as it gets or I might expect better results with a different carburetor. Basically it only leaks after sitting not running for a while. Even then it is only a seep. However, it will run indefinately without leaking or flooding the engine out as I found out the past weekend.

I am really looking for peoples first hand experience with what I stated above. Perhaps I should clarify. I am not saying I want to use a different carb rather the same carb but another one from a salvage.

Do you know what ELTO stands for?

Yep. I know all about Evinrude, Elto, OMC, Johnson, and Gale's history. Corporate executives were just as shrewd back then. The only thing I don't understand is why Evinrude and Johnson were marketed as equals. It just doesn't make any business sense to me. Must have been part of the merger agreement. Forming OMC and introducing Gale as a less expensive alternative totally makes sense. Might as well dominate all segments. However, another mistake was making them just as feature rich and of the same quality as their siblings. However, the technology was not as ?state of the art? and more simplistic. But then again, why throw away something that works. Gale was a good move at the time.

 

[1946Zephyr]

Re: Tillotson Carburetors - Leaky Bowls

Is it leaking around where drain plugs and such? Or is fuel coming out the top? I've had carbs like that leak where gaskets are and end up replacing the part that causes the leak. Is there a possibility that you could post us a pic of the carb and show us exactly where it's leaking?

F_R is a man who is very knowledgable about the old OMC's too. I guess he worked down at the plant, where they casted the parts. From what he says, Johnson had the biggest die cast machines in the country and built parts for all three divisions. Evinrude built the cranks and other internal parts.

Oddly enough, eventhough Evinrude acquired Johnson in 1936, they didn't follow identical designs till the mid '50's. They shared designs in the RD's and JW's in the early '50's but it was '56 when they finally decided to have all the same sizes for both, such as the 5.5's, 7.5's, 10's and 15's. Just change the engine covers and you're set.

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

The picture in the link below is the same carb.

http://cgi.ebay.com/ebaymotors/3-HP-Evinrude-Antique-Outboard-Motor-Parts-Carburetor_W0QQcmdZViewItemQQhashZitem3ef6129694QQitemZ270416385684QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

It is leaking out the top where the float indicator/needle comes out the top of the bowl. It is not a gasket issue. It is meant to come out the top, especially if you "prime" it. Again, only after sitting for a long time and it is just seeping out.

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

No takers?

Someone has to be out there that can either say "I had one of those back in the day and it always leaked if I left the fuel valve open" or "I had one of those back in the day and I forgot to shut the fuel valve off several times and never had an issue"

 

[F_R]

Re: Tillotson Carburetors - Leaky Bowls

No takers?

Someone has to be out there that can either say "I had one of those back in the day and it always leaked if I left the fuel valve open" or "I had one of those back in the day and I forgot to shut the fuel valve off several times and never had an issue"

OK, lets just face up to the truth. Dripping carburetors were almost the norm back in those days. Noboby worried about it back then. If it is just a drip after sitting awhile, you MIGHT improve it by lapping the seat with some Bon-Ami. More than likely you will just make it worse. I'd leave it be.

BTW, are you sure it is a Tillotson? I thought they were made by Evinrude/Elto. Poppet valve carb, right?

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

Not 100% sure it is a Tillotson. The one in the eBay picture is the the same carb I have on mine. Yes it is a noisy poppet valve carb Just has very similar parts to the carbs on my 53 Sea King 5hp which I have been told are Tillotson. I also remember running accross an old ad that showed a 1939 Evinrude with a Tillotson Carb. Ad was for Tillotson.

Thanks for the info. It was very helpful information. If your read my youtube blurb about it below you will understand why

I have a video of the outboard on you tube:
http://www.youtube.com/watch?v=UD9pj2VWIGc

This is the blurb I wrote up about it.
This is the 1939 Elto again that my Father gave me back in November. Was seized, tank was totally rusted, and carb was really bad. I freed it up the got the tank cleaned and patched up and the carb cleaned to the point it would run. However, the float valve wasn't seating because of all the corrosion causing it to flood out. I used some JB Weld to form a new valve seat. Waited until it was "moldable" then pushed the needle through and seated the tapper into the JB weld to form the seat. I then coated with thinned out Seal All to keep ethanol from creating an issue. JB Weld says that it would be fine fully cured but my test sample proved otherwise. Maybe my mixture was wrong or JB weld was old?? Was cured for 1 week. Seal All did the trick to coat it and I know that holds up to ethanol. It works great while it is running but if left sitting for a while, eventually it leak out the top of the bowl so I just shut off the fuel tank valve. I will eventually find a good used carb for it. Maybe next weeked

 

[F_R]

Re: Tillotson Carburetors - Leaky Bowls

Not 100% sure it is a Tillotson. The one in the eBay picture is the the same carb I have on mine. Yes it is a noisy poppet valve carb Just has very similar parts to the carbs on my 53 Sea King 5hp which I have been told are Tillotson. I also remember running accross an old ad that showed a 1939 Evinrude with a Tillotson Carb. Ad was for Tillotson.

Thanks for the info. It was very helpful information. If your read my youtube blurb about it below you will understand why

I have a video of the outboard on you tube:
http://www.youtube.com/watch?v=UD9pj2VWIGc

This is the blurb I wrote up about it.
This is the 1939 Elto again that my Father gave me back in November. Was seized, tank was totally rusted, and carb was really bad. I freed it up the got the tank cleaned and patched up and the carb cleaned to the point it would run. However, the float valve wasn't seating because of all the corrosion causing it to flood out. I used some JB Weld to form a new valve seat. Waited until it was "moldable" then pushed the needle through and seated the tapper into the JB weld to form the seat. I then coated with thinned out Seal All to keep ethanol from creating an issue. JB Weld says that it would be fine fully cured but my test sample proved otherwise. Maybe my mixture was wrong or JB weld was old?? Was cured for 1 week. Seal All did the trick to coat it and I know that holds up to ethanol. It works great while it is running but if left sitting for a while, eventually it leak out the top of the bowl so I just shut off the fuel tank valve. I will eventually find a good used carb for it. Maybe next weeked

Holy cow. A JBWeld seat? Man, I'd say you did good.

 

[1946Zephyr]

Re: Tillotson Carburetors - Leaky Bowls

Yea, there were some Evinrudes built with Tillotson carbs. They were a decent carburetor from what I seen. My 51 Fastwin 14 had one. One thing different is, the low speed needle only goes a quarter turn out from bottom, rather than the normal 1 1/2 turns, like the OMC carbs did. If you turned the low speed out, it made it run leaner. Run it an 1/8th of a turn out, it would richen the mixture. In those models, the low speed screw was an air bypass screw, rather than a fuel flow. You'll find Tillotson carbs on just about anything out there. I've even seen them on old lawn mowers.

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

Is there a definative way to know what brand the carbs are. For all I know they are all Evinrude/Elto/OMC ?

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

Yea, there were some Evinrudes built with Tillotson carbs. They were a decent carburetor from what I seen. My 51 Fastwin 14 had one. One thing different is, the low speed needle only goes a quarter turn out from bottom, rather than the normal 1 1/2 turns, like the OMC carbs did. If you turned the low speed out, it made it run leaner. Run it an 18th of a turn out, it would richen the mixture. In those models, the low speed screw was an air bypass screw, rather than a fuel flow. You'll find Tillotson carbs on just about anything out there. I've even seen them on old lawn mowers.

The carb on my Elto has 1 jet which is in play the whole range. You need to adjust it with the speed of the engine. Out richens, in leans. Runs best at about 1/4 out for midrange.

 

[1946Zephyr]

Re: Tillotson Carburetors - Leaky Bowls

Tillotson carbs are very plainly marked with their brand name. Very hard to miss. I believe you have the standard old poppet valve carb, if you turn the knob to the left to prime it. These are made by OMC. With those little boogers, you loosen up the set screw on the prime lever and set the needle jet to where the engine runs it's best. Once you establish a good needle position and get it running good, then you set the prime lever back and tighten the set screw. These are actually good carbs and easy to work with. I had one on my 1937 Evinrude Sprotsman and a 1939 Evinrude Ranger.

 

[F_R]

Re: Tillotson Carburetors - Leaky Bowls

Is there a definative way to know what brand the carbs are. For all I know they are all Evinrude/Elto/OMC ?

Jason, as far as I know, the poppet valve carburetors you are talking about were made by Evinrude/Elto. You are the first one I've ever heard say otherwise. The other one that people are mentioning here is made by Gale. Now, Tillotson certainly did make carbs for just about everybody at one time or another. The Tillotson model MD was extremely popular and is what was on the 14hp Evinrude.

 

[JasonAych]

Re: Tillotson Carburetors - Leaky Bowls

Someone may have misguided me early on. The carbs on the Handitwin and Sea Kings do not have "Tillotson" on them anywhere. While I am not new to engines, outboards are a bit new for me.

The Handitwin does not have a knob or a prime lever. It has a fuel mixture lever. To "prime" it, you would have to push down on the needle that comes out of the top of the bowl. I can usually get it started without priming it. I just open the one and only needle jet all the way open and it usually starts around the 3rd or 4th pull. Once warm, it starts on the first pull. Once started, I quickly lean it out by about 1/8th turn back in. As it warms up, I set it to about 1/4 turn out (the lever is positioned in the middle). If I advance the timing lever, I have to lean it slightly. If I go to a low idle, I have to richen it slightly.

The Handitwin carb is very basic. It is made up of a fuel bowl and venturi side by side. The bowl fills from the bottom. It is controlled by a brass needle with a tapered end through a tapered hole (now formed from JB Weld and coated with seal all ) at the bottom of the bowl. The float is just a round chunk of cork with the needle through it. There is a clip on the bottom and top of the float. There is a circuit that goes from the bottom of the bowl to the needle jet. The needle jet meters a small drilled jet that enters the venturi right at the rim of the poppet valve. The poppet valve has a light spring on top of it. The poppet valve sort of does the same job a reed does as well as act as a fuel/air flow valve. The more vacuum the more it opens. At lower rpms you can really hear that poppet valve ?clapping?.