Home › Forum › Ask A Member › Johnson 3HP JW-17 Compression woes › Re: Johnson 3HP JW-17 Compression woes
You may very well have stuck rings causing your low compression #s. If in fact your gauge is accurate… if you have the exaust cover off, a quick way to check for stuck rings is to use a small (pocket size) screwdriver, and gently push the ring straight in to the piston ring groove. If it springs back out slightly when you let off the screwdriver, the ring is probably free. Stuck rings won’t move in and out at all when pushed on with a screwdriver. This is due to carbon build up that glues the ring in the groove tight. It takes some patience, but I’ve freed some stuck rings up with Quicksilver Powetune, or BRP (OMC) Engine Tuner. Lay the motor on it’s side so the product has a chance to soak in. Sometimes though, they can be stuck so bad that the powerhead will need to come apart.