See full version: 7. 5 johnson outboard in Boats For Sale
Mid-70s 2-stroke is seven and a half horse Johnson outboard engine. Used it on a 14 foot flat bottom for duck hunting . Runs great have a 3 gallon Atwood plastic tank Bought this year comes with it. $600 or trade for dirt bike ATV hunting and fishing ECT. I can meet near I-75. E mail only more
Johnson 7.5 HP Sea Horse motor. Not sure exact year of the motor. Does not include fuel tank or hose. Carburetor Kit installed and fuel pump replaced 4 years ago. Fired it up before listing on and it starts. Outboard $200 TEXT,CALL, EMAIL IN THAT ORDER FOR BEST RESPONSE' I AM LOCATED IN THE ISANTI MN AREA / NORTH METRO AND I DO GET TO THE CITIES SOMETIMES AND AS FAR NORTH AS RUSH CITY SOMETIMES.T
I have a Antique 1957 7.5 Johnson Outboard Motor for sale , it starts and runs very good , this is a collectors item .Asking $ 400 O.B. O. no low balling .If interested send me a e-mail through this site and then I will call you once you give me your number . Joe more
I have a Antique 1957 7.5 Johnson Outboard Motor for sale , it starts and runs very good , this is a collectors item .Asking $ 400 O.B. O. no low balling .If interested send me a e-mail through this site and then I will call you once you give me your number . Joe
If you can not get it to run, then inspect your cylinder head cover. The head gasket may be damaged. You would have to replace the head gasket and re-torque the head bolts. Torque range is 60 to 84 inch pounds with a torque wrench. Tighten 50% torque value first pass and then 100% torque value the second past. After you run the engine a while, stop and let it cool a bit and then retorque at 100% torque value. [links]
Re: Johnson 7.5 hp compression here
1957 ad-11 if that makes a difference. here
Well, the compression value should be within 10% of each other. 14 point spread is a bit much. Couple of things you can do, if you can get the motor running, is to decarb the motor. The piston rings may be coked up with carb and stuck and may benefit from a decarbing to free the rings up. Seafoam is only $6 to $8 a can. Cheap enough to try. (Prior to decarbing, remove both sparks and pour and ounce of Seafoam in each cylinder. Replace the spark plugs and let it sit a day or two with the spark plugs facing the sky. If there is carbon causing the rings to remain stuck, the Seafoam may dissolve the carbon some and free the rings for better compression.) But I would still do the full decarb as per the instruction below.
Link for a decarbing instructions. [links]
I will provide a torque pattern diagram that is similar to your motor as an attachment.
RPM Information: 4000
Your engine's RPM range is important in choosing the right propeller for a given application. For example, if you look at your tachometer at top speed and it is not within the engine's RPM range then that is generally not good. You want your RPM's to be within the proper range while at wide open throttle (WOT). Be sure to do your testing under your normal boating conditions and with a good propeller (not bent, cracked, or excessively chipped). [links]
The iboats Outboard Motor Forums are another excellent source of information. here
[links]
RPM Information: 4000
Your engine's RPM range is important in choosing the right propeller for a given application. For example, if you look at your tachometer at top speed and it is not within the engine's RPM range then that is generally not good. You want your RPM's to be within the proper range while at wide open throttle (WOT). Be sure to do your testing under your normal boating conditions and with a good propeller (not bent, cracked, or excessively chipped). [links]
The iboats Outboard Motor Forums are another excellent source of information. here
[links]