1967 6 HP Johnson smoking

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TonyL

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I just traded around and got a 14 ft flat bottom with a little 6 HP Johnson on it. Motor seems to run fairly good and starts easy enough if it has ran recently. But the darn thing is smoking like crazy all white smoke. Also it isn't spitting a good steady stream more of a heavy spray I guess is this something I should worry about.
I'm going to run some high test gas and seafoam thru it hopefully that will clear the smoke out. Never fooled with outboards much so new territory for me.
 
TonyL said:
I just traded around and got a 14 ft flat bottom with a little 6 HP Johnson on it. Motor seems to run fairly good and starts easy enough if it has ran recently. But the darn thing is smoking like crazy all white smoke. Also it isn't spitting a good steady stream more of a heavy spray I guess is this something I should worry about.
I'm going to run some high test gas and seafoam thru it hopefully that will clear the smoke out. Never fooled with outboards much so new territory for me.

Tony, congrats on the new motor and welcome to 2stroke world.
First thing is to make sure you're running the proper fuel/oil mix 50:1 with TCW3 outboard oil. 2 strokes like oil and do smoke a bit.
2nd, make sure you have the motor deep enough in a barrel of water to completely submerge the water pump by several inches.
Also, its good practice to change the water pump impeller when you don't know when it was done last. And no, you can't take the seller's word on that.
Good luck.

jasper
 
I would be a little suspicious of white "smoke". A good rule of thumb is that oil burns with a blueish tint of smoke, water creates steam with a whitish tint and fuel burns with a blackish tint. Maybe not always but in general. Head gaskets are known to spring leaks with the water escaping the water jackets to the cylinder where it turns to steam and exits the exhaust. The first thing I would do is replaced the impeller to make sure you have a good pumping system and then work from there.
 
Thanks for the quick replies. That's kinda what I was figuring just from scrolling thru the forum was to replace the pump. Is it fairly straightforward? From what I'm gathering I just drop the lower unit.

Also I'm guessing a carb rebuild or good cleaning would probably help it start a little easier when its cold.
Thanks again for the help. I will post pictures soon once I get it running good going to start modifying the boat some. Its a blank slate no lights nothing. I'll mostly be hunting and trapping from boat be using it on the lake and river.
 
Tony, a compression test is easy to do and will tell you the condition of the cylinders. Invest in a tester, you'll use it many times on many motors. While checking on the impeller, check for the gromett where the water tube enters the pump. Mine was AWOL! It pumped, but not well. You should be able to find articles, info, manuals, etc on line to help you. If not, ask. A very kind gentleman, right here on Tinboats, turned me on to a WEALTH of info for my '52 5 horse(thanks man, I still owe you my first born.......please LOL). The folks at AOMCI.org can also help a great deal.

Gary
 
Update one the motor. It rained all day long so I got to mess with it a bit. Took lower end off the impeller looked like it had been replaced fairly recent it was still in real good shape. So cleaned everything real good and found the water pump probably whoever worked on it last forced the end into rubber grommet and it was wedged rolled up in a ball so just barely was getting any water thru especially when first started.

Messed with getting it starting easier and idling a little better got it going a lot better and smoking issue resolved it seems. But it wants to die when I throttle over to shift. Is this something I should just learn to live with or a easy fix. Idles good when throttles on start. Over all I'm pretty happy with it have about 300 in boat and motor
 
I had a few of the Johnson 6hp motors that acted the same way. Would not idle below the shift position. The head gasket was the problem. It was pulling in just enough water to kill the motor. You could see water drops on the spark plugs.
 
How big of a job is it replacing the head gasket on these or should I just use it like it is and live with it.?
 
TonyL said:
How big of a job is it replacing the head gasket on these or should I just use it like it is and live with it.?

A compression test will tell you if you have a blown head gasket. You can borrow a compression tester for free at most auto part stores like autozone or oreillys.
 

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