1961 40H.P. Johnson Smoking Badly

[Saskatoon2005]

Sorry, and I know this was already asked, although not answered very well...<br /><br />I have a 1961 40 horsepower Johnson. I had a heck of a time getting it started. I have recently purchased it and was told it sat for four years. I took apart the carburetors and cleaned them very well. I put them back in and with in two tries.....it started. I have a new problem. My johnny smokes alot....can I adjust the carburetor while the engine is running? Is it too lean? The smoke is white and very smelly. I have the outboard sitting in a large garbage can full of water. It just spits water out of it and lots of black ooze from the exhaust. Any help would be very very thankful.

 

[WillyBWright]

Re: 1961 40H.P. Johnson Smoking Badly

Welcome to iboats. <br /><br />Can you give us a model number? The 40s of the 1960s only had one carburetor. But no matter, you can't adjust the carb(s) in a garbage can. You can't wind it out and put a load on it, so the best you can do is ballpark it. You can adjust the idle circuit, but not the high speed.

 

[JB]

Re: 1961 40H.P. Johnson Smoking Badly

Many people are shocked by the amount of smoke and stink that a 2 stroke in a barrel normally makes, Saskatoon. That may be the case with your engine.<br /><br />Did you set up the engine by the book, particularly the linkage and synchronization?<br /><br />If so it is time to put her under load on the water and carefully observe performance and cooling.<br /><br />If not, get a manual and do it over. Then put her on the water, etc.<br /><br />Let us know what you find, and good luck.

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

If you click the little man-next-to-house at the top of my post, you'll see my '62 28hp (somewhat similar fundamentally to your 40hp) running on a day with a little wind. If after adjusting the idle the smoke is still worse than that, try pulling both spark plugs and comparing the insulators on their firing ends. A leaking fuel pump or weak spark can make it smoke excessively.

 

[WillyBWright]

Re: 1961 40H.P. Johnson Smoking Badly

I had a 1960 which was pretty much identical to a 1961. The lower High Speed adjustment was about 5/8 turn out, the upper Low Speed adjustment was about 1 turn out. That seemed to be fairly universal around here. Elevation affects it.<br /><br />In the middle of the bowl there is supposed to be a thick gasket around the nozzle in the middle. If that isn't there or it's shrunken and leaking, it's about impossible to get into proper adjustment.

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

Wow, <br /><br />everyone, thank-you for your quick and informative response. I only have one carburetor (sorry I added an "s" to carburetor) and yes the thick gasket has been crumbling apart significantly. Does anyone know how to get a new gasket? My model number is RS-23 or RD-23. It has a fixed high speed and only the lower speed nozzle can be adjusted. It smokes quite lot but it runs and idles pretty smooth. I still haven't checked the compression because of the snowy weather we have recently received. I must admit I am very eager to get it out on the water and run it out at high full throttle. I have to also say that I have a manual...got it out of the library and did set it to the manual.

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

Pick up a carb kit from your local Johnny/Rude dealer and rebuild it right. Kit should only be around $30. There are aftermarket kits available for around $20, but they don't come with a modern fuel tolerant float to replace the troublesome cork one.<br />Do you happen to remember the brand of manual the library has? Would it be the Seloc one with the blue cover, the Clymer one or something different?

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

I have the Clymer edition of manual. I will definately pick up a carb kit to rebuild it right. I will let you know of my results....and thanks again for your quick response.

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

I have another question about this statement:<br /><br />"In the middle of the bowl there is supposed to be a thick gasket around the nozzle in the middle. If that isn't there or it's shrunken and leaking, it's about impossible to get into proper adjustment."<br /><br />Will a carb kit come with this new gasket to replace the one that is breaking down?

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

Yes. Both the aftermarket and the factory rebuild kits come with a new one. The factory rebuild kit replaces essentially everything that's not metal in the carb, plus the needle, needle's seat and core plug. The Seloc manual misses the most important step. I'm not sure about the Clymer's so here it is:<br /><br />Disassembling:<br />Your new carb kit ought to come with a replacement, slightly convex core plug. Before proceeding, make sure they're they are the same size as as the ones you are about to remove. If all is well, drill a 1/8" hole in the centre of the core plug. Then insert a small screwdriver or nail through the hole, and pry the plug out. It is very important that while drilling and prying, you do not let anything damage the surfaces underneath the plug. So restrict the drill bit from piercing much more than 1/16" beyond the core plug.<br />Clean the cavity under the core plug and ensure all the idle orifaces are clear.<br />Assembling:<br />Coat the outside edge of the core plug with a slight amount of fuel proof gasket sealer. (Although this step isn't strictly necessary, I find it helps seal the plug and saves problems down the road.) Now place the plug convex side up atop the boss where the plug rests. Then, using a small drift and hammer, tap the top of the core plug so it expands until it jams tightly against the core plug's socket. Give it one extra tap for good measure.

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

Okay, like I promised, <br /><br />I finally was able to get the compression checked...and let me tell you of my experience so no one ever does what I did...<br /><br />I have a compression gauge with an extension to get into hard to reach areas...now mind you, I did not need the extension but I though since I had it I would use it...I screwed the whole extension in and I did not recognize that the threads were twice the length of the spark plug threads. I turned the engine over and it stopped dead where the piston hit the compression gauge extension...Now I did not know what had happened and I recalled that I was able to turn the engine flywheel by hand. I was now not able to...after realizing what had happened I am panicking of what might have happened. I quickly screwed out the extension and screwed in the regular end. I took both cylinder readings and there was no damage to the extension so I hope that means that there is no damage to the cylinder or the piston head.<br /><br />I have not run the engine since this happened...I am a little worried.<br /><br />Anyways...the compression of the top cylinder is 105. The compression of the lower cylinder is 120. Do you think the difference in the readings is because of the threaded extension?<br />The lower reading [the top cylinder] is from the one that had the threaded extension.<br /><br />Please advise a.s.a.p...I am very worried.

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

Don't sweat it. It'll take a lot more than the torque of the starter to damage things internally. Presuming the extension is made of brass, it will be more damaged than the top of the piston.<br /><br />15lbs of difference is boarderline IMO. Run the test again and make sure all the conditions are the same. Throttle position, number of revolutions (go for 5+).<br />Another idea - say your fuel pump was leaking or the bottom cylinder was misfiring. That would leave extra oil on the walls of the cylinder and it gives an unusually high reading. This may be what's going on with the difference.

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

Awesome, thankyou very much Paul, you really know how make a guy relax....now how do I check the fuel pump for leakage or how do I check the bottom cylinder for misfiring. I do have a manual so if I need to check the timing and stuff let me know so I can do these things. I have not had the flywheel off since I bought this engine...so the points could be dirty and in need of replacement. <br /><br />One last question...<br /><br />Could this explain the smoking that I have been witnessing from the engine?<br /><br />....and thanks again...and yes the extension is definately brass.

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

Yes it could. Could also be that boss gasket like WillyBWright said too though. <br />It's pretty easy to see if the fuel pump diaphram has been ruptured. Just pop the hose off the 'Pressure' line on the fuel pump (the one that connects to the lower intake bypass covers). Then pump the primer bulb till it's hard. If any fuel comes out of that hose nipple, the diaphram must be ruptured.<br />The fix for it is simple and cheap. (nice words huh?)<br /><br />The bottom spark plug's insulator may appear blacker or damper than the top one if this is the case too. Can you see any difference between the two?

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

unfortuenately Paul, <br /><br />I had changed the spark plugs recently when I could not get the motor running. So the insulator's look identicle at the moment..should I run it to see if I get a difference in insulator colors.<br /><br />...thanks again...

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

Does anyone else know why there is a 15 psi difference between my two cylinders? I have a carb kit and a tune up kit as well as a impeller on it's way to my house right now. Will one of these thing fix my problem?

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

Perhaps. Left over fluids (gas/oil) in the cylinders can have a dramatic effect on compression readings. If you've been running rich or misfiring (which you have most likely) then excess fluid can collect in one cylinder or another.<br />Drain the carb of fuel (there's a small brass slot screw in the bottom of the carb for this), crank the engine over a few times with the spark plugs in, and re-take the compression test. That should blow-out any excess fuel/oil. If the fuel pump has been leaking, there might be quite a bit of fluid in there.

 

[CATransplant]

Re: 1961 40H.P. Johnson Smoking Badly

Saskatoon,<br /><br />Not to worry too much. The compression is probably going to be OK. This engine hasn't been run for awhile.<br /><br />When I first checked my '58 RDS20 35hp, compression on both cylinders was 85...too low. But it started. After my lake test, both test at around 105.<br /><br />The trick is to get this thing running properly, then use it for awhile. Check the compression then, after you've had a chance to get it on the water and run it full out for awhile.<br /><br />A suggestion that can't hurt anything: Add a full bottle of Sea Foam to the first tank of gas you run through this engine. It can't hurt, and might just help.<br /><br />Again, keep us informed.

 

[Paul Moir]

Re: 1961 40H.P. Johnson Smoking Badly

CATransplant has good advice there. It's not odd to have one, two, or three rings stuck on these outboards which will also give uneven compression. Carbon (coke really) builds up in between the rings and the piston so they stick in the grooves. Decarbing the engine frees them up. Roscoe has a good FAQ in the Engine FAQ Forum, but don't worry about it until you have that carb & fuel pump rebuild done.

 

[Saskatoon2005]

Re: 1961 40H.P. Johnson Smoking Badly

Okay, <br /><br /> finally I was able to rebuild the carburetor. I can't get it to idle slower than start position. When I initially pumped the carburetor after rebuilding it...it flooded miserably and fuel shot out of the carburetor. Then once it filled the float assembly (I think) it no longer flooded and no longer shot out of the carburetor.<br /><br /> I can't get the motor to go down to slow on the throttle. Does this have to be done on the water? I can only get it to run in the start position and am able increase throttle. <br /><br /> Another problem is overheating. The power head gets so hot you can not touch it. I have a knew impeller and will replace it a.s.a.p.