Couple problems with Johnson 28

I took the boat to the lake last weedend and it ran great for a couple hours. Then when running wide open it seemed like it jumped out of gear, so I backed it down and it would run but not wide open. Then it eventually died on me, I was just about to use the trolling motor to get me back when it started again. But, it was running real rough. I bought the boat from my dad and he told me that the metal gas can probably was rusted and I needed to replace it. So, I got new gas cans for it this weekend and I noticed a real thick black oil running out of the prop. It wasn't doing this last weekend before I took the boat out for the first time...I'm guessing it is gear oil?? any suggestions? Again, its a Johnson 28hp and I believe its a late 80's model...Thanks!

Re: Couple problems with Johnson 28

was this the first time this motor has been run in a while? look on the transom mount or side of the motor near the transom mount,and give us the model #. there are a lot of things this could be. crud from the fuel tank, unburnt fuel do to fowled carbs, did it run hot. when was the impeller changed, last decarb, last carb rebuild & cleaning, what was your oil mix.

Re: Couple problems with Johnson 28

Hey dwalker! Welcome to iboats!<br /><br />When the engine seem to "jump out of gear", did the rpms rev up and you seem to slow down or did it feel like you were hitting a log? OR....was it something different?<br /><br />If it started running rough, check the spark on each cylinder...chances are one cylinder quit firing....which may be the case. The heavy black oil from the prop is most likely unburned fuel oil mix migrating down out of the exhaust cavity. If you have a cylinder with a weak or no spark, this would cause it to be heavier. Take a smell of it....smells like gas/oil mix.<br /><br />The problems...kicking out of gear and running rough may be two separated problem or one problem making it seem like two problems.<br /><br />Have you done any maint to the engine lately like new gear lube, new plugs etc.

Re: Couple problems with Johnson 28

yes the rpms did rev up. My dad changed the plugs last year I think, the boat hasn't been used since last summer and I'm not sure about the gear lube. I'm about to go check and see if it smells like gas/oil mix, and I'll see if I can find the model #. thanks for the help so far!

Re: Couple problems with Johnson 28

model # J28ESLCCR<br /><br />it is a thick black substance with no odor at all

Re: Couple problems with Johnson 28

The year is 1988. Hard to believe no odor....but if it's thick and gooey, probably comin' from the exhaust. You should check the gear lube at least.<br /><br />If the rpms went high and the forward movement of the boat seemed to slow down, you could have a spun hub in the prop. This is like a classic indication of a spun hub....high engine revs and the boat slows down.<br /><br />What you can do is pull the prop and take a marker, waterproof, and draw and index line from the rubber part of the hub out to the metal part. Put the prop back on and take it out. If the problem occurs again, pull the hub and check the index line. If the inside of the index line is no longer inline with the outter line, the hub is spun.

Re: Couple problems with Johnson 28

From what I can tell of the parts diag. on the Evin/John site, that model still has the old style lower unit. It doesn't have thru-hub exhaust. Since that seems to be the case, about all that could be leaking out at the prop would be the gear lube, possibly contaminated by exhaust intusion.<br /><br />What OBJ said about checking for spun hub. It appears you may have to dismantle the gearcase to install new seals. At that time, check the shift dog for wear. That is another possibility for causing your symptoms.

Re: Couple problems with Johnson 28

Yep....BB is right on about the gear case.<br /><br />Drain the gear lube and see what it looks like. I bet if it's the same color as what leaking out the prop, the missus will be in yer ear in short time yelling about the smell...... <br /><br />Here's the link to the BRP site. Click on engine diagrams and follow the prompts. You can get a parts break down on your gear case and see whats what.<br /><br />EDIT: And if the hub is spun, just take it to a prop shop or dealership and get it rehubed. No big deal. Cheaper than a new prop.<br /><br /> http://www.evinrude.com/en-US/

Re: Couple problems with Johnson 28

thanks to the both of you. You've been alot of help, I'll let you know how it goes!