1955 15Hp Updated info

[Dutchoven]

Okay. Today I installed the gasket set into the fuel tank. Stopped the leak. Replaced The hose. Replaced the springs in the recoil starter. Got the oil that was recomended and measured exactly 24:1.

The engine ran rough and smokey. I did the adjustment on the HS and LS knobs. It seems to still be smokey and the power isn't what I would have thought.

There is a weird hesitation or jerk from time to time where the whole head suddenly jerks then returns to speed. I was wondering about the spark so i used a contact type tester ( Neon Bulb type, touch the wire and it lights up ) and noticed that the spark did not appear to be very fat on either plug. Then at slower speeds the spart would go fat for a stroke or two.

I am wondering if the magneto coils are cracked or shorting erratically. I am spending a ton on this motor already. the coil I can get for under $20 each. I still dont have a manual and I dont know if I can do this myself.

Could someone help me? I would like to use this motor

 

[Paul Moir]

Re: 1955 15Hp Updated info

Do a spark gap test. If you can get the spark to jump a 3/8" gap on both cylinders, then the ignition coils, etc are fine. 1/4" would be passable too.

Smokey suggests you're running rich. It'll rob you of power too. Pull the spark plugs and examine their firing ends if they're somewhat new. Ideally, the porcelain insulation inside the combustion chamber should be a tan to chocolate colour. If they're black and oily, that confirms a rich running problem.

Don't expect big fat sparks from that magneto. They won't compare to what you would get from a modern ignition system.

 

[F_R]

Re: 1955 15Hp Updated info

If the coils are as old as the motor, you can bet that they are cracked. I believe that motor has an inspection hole in the flywheel that you can see the coils thru without having to pull the flywheel to look.
Periodic coughing or sneezing at slow speeds is caused by too lean fuel/air mixture. Try tweaking the low speed needle a bit to the left to richen it up.
True, the sparks are not as impressive as the lightning bolts that you get from a modern motor, but they should jump a 1/4" gap with ease. That's enough to light your eyeballs up if they zap you.

 

[cougar1985]

Re: 1955 15Hp Updated info

im with fr original coils will most likely be cracked and are known for this.get the seirra coils.they are better than the originals.

 

[F_R]

Re: 1955 15Hp Updated info

Hey, Dutchoven, can I give you some advice? Noting that your motor is a 1955, be aware that those motors had some serious problems when new. If it were mine, I would be very cautious about spending a lot of money without checking it out first. The problem was the lower main crankshaft bearing seal. They failed and let water get into the crankcase, which rusted and destroyed all the bearings. Grab hold of the flywheel and see if you can move it fore and aft. You should not be able to move it more than a couple of thousandths of an inch. Running, there should be no whirring or grinding sounds. The next step may be intimidating, but I would pull the powerhead and inspect the seal. Some had a stainless steel wear ring on the end of the crankshaft, which would often crack and fall off, leaving a gap between the shaft and seal. Others did not have the wear ring and were OK. At any rate, the seal should be replaced because they weren't all that great.
It has been said that a boat is a hole in the water that you fill with money. A word to the wise.

 

[tashasdaddy]

Re: 1955 15Hp Updated info

Dutchoven, are you doing this on the boat in the water or in a barrel? the smoking could be still running rich, otr could be carbon build up burning off. remember these old engines originally used 30wt oil and not tcw3, and as i believe it has never had a decarbonization this could cause the smoking, mine smokes when first started and decreases as it warms up. what are you doing when it jerks and shakes, is it in gear and how fast. does it feel like you hit something under the water. enough for now. answer these, be as specific as you can, don't care if it is long.

 

[Dutchoven]

Re: 1955 15Hp Updated info

Thank You all for your quick response. First, I Ran it in a barrel off the end of my boat. I didn't run it in gear. That would get me soaked. I mixed 6 gal of gas with tcw-3 measured using a measuring device I got from West marine.

Now I will check the bearing run-out by grabbing the flywheel and moving for and aft. I didn't hear any grinding sounds before while running.

I noticed that the plugs were wet not brown. I did a slow speed and high speed knob adjustment and the smoke would change but it still didnt seem right.

I am ignorant about carberators. Is there a rich mixture screw? this is not the slow speed knob? the small knob on the top.?

I can understand that I may have a rich mixture problem but that jerking has the feel of something electrical.

Ill do the spark test. ill report on this later today

 

[tashasdaddy]

Re: 1955 15Hp Updated info

ok you need to get it running and put the boat in the water, adjust the high speed first then the low speed, the bottom knob is the high speed adjustment, the top is the slow speed and idle adjustment. did you use Joes Reeves post in the engine faq forum to adjust your carbs.

 

[Dutchoven]

Re: 1955 15Hp Updated info

Yes i did use the Reeves post. I grabbed the flywheel and it only moved a few thousanths.

I Am attaching a couple of Quicktime movies I made of the thing running. You can use Apple Quicktime to view. There is no sound, Sorry.

Tell me what you think about the smoke and it shows the jerking although it wasnt doing it bad when I filmed it.

Please advise .

 

[Dutchoven]

Re: 1955 15Hp Updated info

Yes i did use the Reeves post. I grabbed the flywheel and it only moved a few thousanths.

I Am attaching a couple of Quicktime movies I made of the thing running. You can use Apple Quicktime to view. There is no sound, Sorry.

Tell me what you think about the smoke and it shows the jerking although it wasnt doing it bad when I filmed it.

Please advise .

 

[Dutchoven]

Re: 1955 15Hp Updated info

Yes i did use the Reeves post. I grabbed the flywheel and it only moved a few thousanths.

I have a couple of Quicktime movies I made of the thing running. You can use Apple Quicktime to view. There is no sound, Sorry. Please give me your email address and I'll send it to you. This site wont allow attachments of that size.

Tell me what you think about the smoke and it shows the jerking although it wasnt doing it bad when I filmed it.

Please advise .

 

[Dutchoven]

Re: 1955 15Hp Updated info

here is a picture of the motor. look at all the oil in the water!

 

[F_R]

Re: 1955 15Hp Updated info

Nice picture. Just kidding. Are you attempting to show us oil crud and foam stuff in a barrel? That is so normal. Those and all two stroke outboards from the era run very sloppy. Some worse than others, but all sloppy. It is way less noticeable on the boat in the water because it is so widely dissapated, but it's still there. There is disagreement as to whether it actually harms the environment. Some of the oil that you put in the gas is burned and the result is smoke. But much more is simply discharged into the water. Motors were slowly improved down through the years, but it now has come to the point that all two-strokes are banned from some areas. Many are not even built anymore because they can't meet emission laws. Welcome to reality.

 

[tashasdaddy]

Re: 1955 15Hp Updated info

ok, i got the quicktime to open. it's a real fogging machine. way, way too much smoke. i personally believe it's burning off old carbon. remember these engine originally ran on 30wt oil mix. it's probably totally loaded with carbon. i think a decarb with Seafoam Deep Creep is inorder. it's really going to smoke during the process. you may have to repeat it 3 or 4 times.