15 JOHNSON TESTING

[REALTREE]

I JUST DID A COMPLETE REBUILD OF A 15 HORSE 1981 JOHNSON , WAS WONDERING HOW TO TEST WITHOUT TAKING TO RIVER? I HAVE A WATER BARREL 55 GALLON DRUM BUT CANT REALLY TEST OVER IDLE, TO MUCH WATER LOSS , CAN I REMOVE PROPELLER TO RUN FASTER OR NOT, I AM THINKING IT NEEDS PRESSURE OR IT MIGHT FLY APART, HOW DO ENGINE SHOPS DO THIS ?

 

[Xcusme]

Re: 15 JOHNSON TESTING

Welcome to iboats Realtree!

Your 55 gallon drum will work just fine for setting the low speed idle mixture screw. Your carb has a fixed high speed jet, so there's no adjustment. I wouldn't remove the prop. Without the prop and in gear, there's no load on the motor . At idle, in Neutral, you'll be limited in RPM's as a safety issue. Do a sync and link and adjust the low speed mixture screw. Leave the top end performance issues (if any) for the lake. Special test props or large long test tanks are used at repair shops.

 

[rickdb1boat]

Re: 15 JOHNSON TESTING

Hi Reeltree,

They have large test tanks and use a test wheel in place of the prop. That way the water doesn't get tossed out, but yet you maintain a load on the motor. Do NOT run it up with no load(Prop) on the motor. You will toast it real quick.. Best way of course is to take it to the water...