Johnson 4hp Seahorse

[fishcracker]

I am new to the world of 2 stroke and I just have a few questions.<br /><br />I was told these little motors spit water out the top somewhere near the impeller when they are running....but I've had it running in a barrel full of water and haven't seen water come out the top. <br /><br />Is 50:1 the correct mix for this motor? I can't find info on this little guy anywhere.<br /><br />Also when checking the leg oil I only see the one screw and it is at the bottom of the leg ,is there supposed to be two??<br /><br />Any help is appreciated.

 

[JB]

Re: Johnson 4hp Seahorse

Can you give us the model number, cracker?<br /><br />I am pretty sure that your engine uses 50:1 mix, but we need the moddel number to confirm that.<br /><br />Most of that type engine exhaust the water from low in the back of the leg and in the exhaust.<br /><br />Some small engines have only one plug to the gearcase. Use it to drain and lay the engine on her side to fill. . .same hole. Use a new plug gasket every time.

 

[fishcracker]

Re: Johnson 4hp Seahorse

Model# 4R73C<br />What kind of oils work best for both the leg and mix?<br /><br />So how do I now what 50:1 is against 20L of gasoline. (stupid question I know). I know I'm gonna feel like a moron once I know!!<br /><br />

 

[Scaaty]

Re: Johnson 4hp Seahorse

Use 3 ounces to 1 gallon of gas...50-1...you can convert it to metric/liters yourself. <br />On the lower, use Marine Lower Gear Lube. Are you sure theres only the lower drain screw? If so, do as JB describes above. Look a little higher up and you might find another screw. Both will accept a big flat blade screwdriver, and look the same. Never touch a screw with a Phillips head thats in the middle of the gearcase....its holds the shift yolk in place. <br />On the exhaust, look at the upper part of the leg. Lots of little holes? Exhaust and water vapor will exit there if pumping good water. Just put your hand behind the holes when running, and your hand will become wet. Hope this helps...good little motors, I have a 84 4HP.

 

[Paul Moir]

Re: Johnson 4hp Seahorse

That's the case with the one fill screw. It takes all of 50ml of 90 weight outboard gearcase lube when it's dry.<br />I recommend you follow Chinewalker's advice and ignore the original and current fuel mix that the manufacturer stated (50:1). I use 32:1 in my '72 4hp mostly.<br /> http://forums.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000007 <br />Although it's a truely great engine, the 4hp lacks the jeweled bearings and proper oil seals of later 50:1 4hp engines. See for yourself:<br /> http://www.shareaproject.com/pages/projectThumbs,p,182,00.html

 

[JB]

Re: Johnson 4hp Seahorse

A 50:1 mix is 20ml per liter, Cracker. But if you want to take Paul's very good advice, 32:1 is 31.25ml per liter.