1953 Johnson RD-14 Outboard Motor

Hello, I recently bought a boat with a 1953 Johnson RD-14 Motor attached. The motor actually appears to be in really good condition by just looking at it and the guy I bought it from said it runs great. I took it to the lake this weekend and it took about 20 minutes of pulling and choking to finally get it started. I had to leave the choke pulled out for a while in order for it to continue running. Otherwise it would shut off. I pushed the choke half way in and put it in forward. When I put it in forward and started down the lake, it really missed and bogged down a lot. It wouldn't run at all on a slow speed, I had to give it a lot of gas in order to keep it running. It is a 25 HP motor and definitely didn't get that much power from the motor. I am going to put some new spark plugs in it and hope that helps?? Does anyone have any tune up suggestions or know any information about this Old motor. Does anyone know the appropriate gas/oil mixture. The guy I bought it from said he used a 50:1 ratio. He said he preferred to run it on the rich side. I would just like to know for sure what it is supposed to be. Like I said, It literally took 20 minutes of constantly pulling the start cord to finally get it to fire, then it didn't run very smoothly after that. Any help or suggestions would be much appreciated. This is the first boat and motor I have ever owned. I know very little about outboard motors/small engines. Would anyone know of where to purchase a user's manual for such an old motor. Thanks for your help,<br />Mike

Re: 1953 Johnson RD-14 Outboard Motor

Howdy, MStone.<br /><br />Welcome to iboats. <br /><br />First, get yourself a repair Manual. www.kencook.com<br /><br />The RD series were great engines and many are in regular use today.<br /><br />There could be a lot of different things wrong in addition to incorrect fuel mix (that engine uses a 24:1 mix).<br /><br />While you are waiting for your manual, go to the Engine FAQ section, Outboard wont start, and find out why it is such a pain to get started.<br /><br />Check your compression. It should be over about 80-90psi and the two cylinders should be within 15% of each other.<br /><br />I suspect the previous owner did a lot of things wrong with that engine in addition to feeding it an oil-lean fuel mix. Check the flywheel key, it may be sheared, also check for the correct spark plugs, Champion J6C (replaced the original J6J), gapped at .030" and gap the points at .020".<br /><br />Once you have your manual, replace the water pump impeller and overhaul the carburetor. Then do a careful "linkage and synchronization" to ensure that the throttle and the magneto advance are cooperating correctly.<br /><br />Let us know your progress and any new questions.<br /><br />Good luck.

Re: 1953 Johnson RD-14 Outboard Motor

Welcome to Iboats, mstone1968!<br /><br />If you had to run the engine with the choke applied, then the engine is not getting enough fuel. This could be because either the carburetor wasn't receiving fuel, or the carb is clogged up and not vaporizing fuel.<br />Since your engine uses the pressure style of tank, I would like to make sure you have your starting procedure down. You did have the tank cap closed and operated the primer?<br />I think it's more likely that you have carburetor trouble though, and it'll need to be rebuilt. It is very easy to do this yourself, but you'll need a carb kit from your local Johnny/Rude dealer and a service manual. <br />If you don't want to buy a manual now, you may be able to borrow one from your local library. But if you plan to service your outboard yourself, then I strongly suggest you buy a reprint of the original factory manual. They're a couple bucks more than the generic manuals, but they're worth more than that. You can get the from one of the following places:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />The fuel/oil mix for your engine is in fact 24:1 (1 quart to 6 gallons) 87 octane gas to TC-W3 rated outboard oil. The spark plugs should be Champion J6C gapped at .030". The lower unit oil is OMC/BRP "HiVis" or other brand 90w outboard gearcase oil.<br />You'll want to do a little more maintanace if the history of the engine is unknown. Check both sparks to make sure you can draw a 3/8" long arc to ground (you'll have to set up a rig for this). Also, you'll want to replace the water pump impeller if it's condition is unknown. They only last a couple seasons. Use notwithstanding.<br /><br />Hope this helps some!<br /><br />EDIT: Looks like JB beat me to it!

Re: 1953 Johnson RD-14 Outboard Motor

In addition if the coils have cracks in them, replace them. If you do not know when it had the water pump impeller changed last, change it also. And change the oil in the lower unit, on the plugs you will find a gasket, replace those each time you change the oil, inspect it for water. when shifting into gear dont baby it. 24:1 = 1 Qt oil to 6 gal. gas<br /><br />Welcome to Iboats

Re: 1953 Johnson RD-14 Outboard Motor

I don't know if you could ever find a service manual that would cover just that engine. Here is something you can do, that engine is a very basic OMC engine. The magneto is the same as any OMC made for years, so coils, points, and condensors are readily available, and all adjustments are made the same. The same is true of the carb. The parts from the early 25, 30, 35, and 40 will fit, you will just have to compare the part you will need, but the float, needle, and seat, bowl gasket, and needle valve packing are still made. When you do the magneto, and the flywheel is off, replace the upper crankshaft seal, it will need it. The item's that may take some searching is the water pump, and head gasket. Gearcase seal's should be no problem if you need them. One thing you can't compare is the horsepower. That old 25 was 36 cubic inch's, compared to the newer 25 that came out in the 70"s that was only around 20 cubic inch's. That old engine will far out pull the newer models. My younger brother, and I had a 25 Evinrude on a 14 Ft. Dunphy when we were Jr. High kids'. It took every cent we could scrounge up for gas, and oil, but it never gave up. Keep us posted as you go along. I may have some water pump parts, and a head gasket if you need it. I will have to look.

Re: 1953 Johnson RD-14 Outboard Motor

The aftermarket impeller 18-3006 is listed for Johnson 25hp, '51-'55, and I *think* 18-3865 is your head gasket (it's listed as a Gale 25hp gasket for '56- 35.7CID engines). I'm sure your local Johnny/Rude dealer will have them too. That impeller was used on later 28, 35 and 33hp engines, so they're pretty common.<br />R.Johnson has a good point about the upper crank seal. If it hasn't been replaced already it's going to need it. Fortunately, the lower crank seal seems to last nearly forever.<br /><br /><br />Pretty remarkable how easy parts are for these old engines.

Re: 1953 Johnson RD-14 Outboard Motor

Hello Everyone,<br />Wow!!!! I want to thank each one of you for the valuable posts!!! I know this information will help tremedously. I live in a small town in Kentucky and its hard to find anyone around here that knows much about these engines and harder to find anyone to work on them. I wasn't sure were to start to get help and I just happened to find this Iboats forum. I'm certainly glad I did. I will take each and every comment and put the information to use. I will definitely keep you guys posted on how things are going with this. When I bought the boat, the man said he used a 50:1 oil/fuel mix but wasnt sure if that was the right one. I hope the engine hasn't been damaged too badly. I am very new to the boating world and outboard engines, so I thank each and everyone of you for you help. I'll keep you posted as I go along with this (and may need you guy's help as I go along. Thanks again!!! Have a great week!!<br />Mike