Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Antique Engine Community > Antique Marine Engines and Outboard Motors
Forgot Password? Join Us!

Notices

Antique Marine Engines and Outboard Motors Discussion on old marine engines, naptha, gas, oil or steam and vintage outboard motors.

Antique Marine Engines and Outboard Motors

Johnson 3 hp fuel ratio


this thread has 2 replies and has been viewed 605 times

Reply
 
Thread Tools Display Modes
  #1  
Old 04-09-2019, 10:57:34 AM
Robrep Robrep is offline
Registered
 
Join Date: Mar 2019
Location: Chino Valley, Arizona, USA
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Default Johnson 3 hp fuel ratio

Hi i have a old Johnson 3 hp engine from around 1964. I got it going but think I put too much oil. (smokes real bad) I need to know what the ratio is with the newer 2cycle oils is. I remember back in the day we used to put a quart of 30 wt in the outboard can and fill it with gas. My dad called them stink pots because of the small. Thanks for any help you can offer.
Reply With Quote
Sponsored Links
  #2  
Old 04-09-2019, 01:10:20 PM
Andrew Mackey Andrew Mackey is offline
Moderator
 
Join Date: Nov 2004
Location: Rockaway, New Jersey USA
Posts: 14,239
Thanks: 2,000
Thanked 6,837 Times in 4,339 Posts
Exclamation Re: Johnson 3 hp fuel ratio

A quart of oil in a gallon can is about a 3 to 1 mix! WAY too much oil! First of all, you do not want to use modern lubes in that engine. It is too thin to lubricate the engine properly. You want to use SAE 30 non-detergent or 2 stroke OIL, not a synthetic or pre-mix lubricant. TCW type 3 2 stroke oil will work well too. You want to use a 16:1 fuel to oil ratio in your engine. 1 cup oil to 1 gallon of gas. Use marine gas if possible, or high test. Don't use E-10 regular auto fuel. If you used that quart of oil to a gallon can, I am surprised that that engine ran without fouling the spark plug! With the 16:1 ratio, the engine should smoke just a bit until it warms up. When warm, there should be very little smoke. If you are running the engine in a barrel or tub, exhaust gasses will be much more visible, as the exhaust is concentrated in the small water area. If running in a tub or barrel, you do not want to let the water get more than luke warm or you will damage the water pump impeller. Make sure your engine has water circulation or you will burn out the cylinders and water jacket near the exhaust ports.
Reply With Quote
  #3  
Old 04-18-2019, 11:09:12 AM
sylvan82 sylvan82 is offline
Registered
 
Join Date: Aug 2017
Location: Dexter, Michigan, USA
Posts: 18
Thanks: 0
Thanked 10 Times in 6 Posts
Default Re: Johnson 3 hp fuel ratio

I have a 1963 / 3 hp twin cylinder that folds in half so it is able to fit into it's plastic carrying case. Out of the case the complete engine is 9" wide x 23" long and only weights 35 lb. Motor has a fuel tank and it's own fuel pump so I can draw fuel from my main fuel tanks. I keep it stowed under a seat in my 18' boat for a kicker motor. It beats the hell out of a wood paddle. I also use the motor on my 10' inflatable. For the last 40 years I have been using the same fuel mix as my 140 hp motor uses. (50 to 1)
Sylvan82
Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Fuel/Oil Ratio on J-321 Victor B Military MEP and Aircraft Gen-Sets 12 05-11-2018 05:43:34 AM
1960 40 hp Johnson fuel mixture lilgreen Antique Marine Engines and Outboard Motors 8 06-07-2011 04:29:33 PM
Info needed Chrysler 3.6 fuel/oil ratio Andrew Mackey Antique Marine Engines and Outboard Motors 4 05-30-2008 10:27:40 AM
Partner 1616 chainsaw fuel mix ratio??? Leland Chain Saw Collectors 3 03-06-2007 06:04:36 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 04:21:18 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277