Problem with my new Johnson....

[cas77]

I have a Johnson 15hp and I believe it's a 2001 or 2002.

It had NEVER been used until 2 weekends ago. Never even seen gas or been tested.

First weekend on the lake everything worked great...

Then last weekend it was running fine for the first hour or two, then there was a little more smoke than usual coming out of it (especially in reverse). Didn't think anything of it.

Then a few hours later it pretty much died. The motor was running, but the fastest it would go was slower than trolling speed. The prop was barely turning. I noticed alot of smoke and black tar colored 'gunk' coming out of the hole where the exhaust is....

Anyone have any idea why this would happen to what is technically a brand new engine?

 

[JB]

Re: Problem with my new Johnson....

You might have "spun" the prop hub, martr.

Can you manually turn the prop when the engine is (off and) in gear?

Prop shop can fix it up for you.

 

[cas77]

Re: Problem with my new Johnson....

You might have "spun" the prop hub, martr.

Can you manually turn the prop when the engine is (off and) in gear?

Prop shop can fix it up for you.

Thanks for answering so quickly!

I'll check when I get home tonight if I can turn it...

 

[Silvertip]

Re: Problem with my new Johnson....

"Pretty much died" doesn't tell us much. Either the engine died or it didn't. If you mean the engine would rev up normally but the boat wouldn't move, you may have spun the prop hub (the rubber between the hub and the outer shell of the prop may be slipping. It's ok to tell us if you hit anything! This allows the engine to rev but the prop slips so the boat won't move. Does the engine rev up ok in neutral (don't go full throttle) just rev it a little to see if that sounds normal. When you were checking the smoke situation, did you have the prop out of the water and for how long? Did the tell tale show a good water stream before the problem? Does it still show a good water stream? The reason I ask is that you may have burned up the water pump impeller if you ran the engine without a water supply. And you may have overheated it if you ran it without a water supply. These are all rather daunting to be sure but then you didn't give us much to go on.

 

[Scaaty]

Re: Problem with my new Johnson....

What was the fuel mix on oil? Sounds like maybe too much, or not enough

 

[ezeke]

Re: Problem with my new Johnson....

You may have blown a head gasket. Happens when running a new motor too hard and not following the break-in procedure. See if re-torque on the cylinder head bolts helps. I would get a head gasket and take a look.

 

[cas77]

Re: Problem with my new Johnson....

Pretty much died" doesn't tell us much. Either the engine died or it didn't. If you mean the engine would rev up normally but the boat wouldn't move, you may have spun the prop hub (the rubber between the hub and the outer shell of the prop may be slipping.

-> Yes you are correct. The engine ran fine, revved fine but barely moved (< 1mph)


It's ok to tell us if you hit anything! This allows the engine to rev but the prop slips so the boat won't move.

-> I didn't hit anything. Unless I hit something when the engine was stopped (It was on and off most of the morning between fishing spots)...but then again I would've felt it even if it was off I think...

Does the engine rev up ok in neutral (don't go full throttle) just rev it a little to see if that sounds normal.

-> No problem revving in neutral,

When you were checking the smoke situation, did you have the prop out of the water and for how long?

-> Had it out for a few minutes...but at no point was the engine even running with the prop out. Noticed the 'gunk' from the exhaust after the engine was off and motor tilted up.

Did the tell tale show a good water stream before the problem?

-> Yes, it's quite the stream on those little things.

Does it still show a good water stream? The reason I ask is that you may have burned up the water pump impeller if you ran the engine without a water supply.

-> There was still a stream, although less powerful than before.

And you may have overheated it if you ran it without a water supply. These are all rather daunting to be sure but then you didn't give us much to go on.

->I made sure it always had water while running.

Thanks for your help!!!

 

[Xcusme]

Re: Problem with my new Johnson....

I'll place $10 bucks on an overheat......(despite the time frame)

 

[tashasdaddy]

Re: Problem with my new Johnson....

spun prop 99%. the black goo was proably rubber melting. never heard of one that bad, but most stop and idle in.

ithink to be safe since the engine has sat since 2001-2, the impeller will be dried out, like and old one, even thou the engine is new. change the impeller for safety of the engine.

 

[cas77]

Re: Problem with my new Johnson....

What was the fuel mix on oil? Sounds like maybe too much, or not enough

I mixed exactly what's in the manual for the break-in period. If it was wrong then there's a mistake in the user manual....

 

[ezeke]

Re: Problem with my new Johnson....

No harm intended, Did you re-torque the head?

I don't know your prop, but if it was new, it was unusual for it to let go.

 

[Silvertip]

Re: Problem with my new Johnson....

Black goo is what bothers me and it can come from only two places. 1) the prop hub and 2) an impeller that has partially melted and pieces have made it through the cooling system and out the exhaust. Since the engine seems to rev normally but no forward drive is present, it has to be the spun hub. Put a scratch on the hub and another scratch on the outer part of the prop directly in line with the first one. Run the engine in gear so that the problem reappears. Stop the engine and check the two marks. If they are lined up the prop is apparently ok and I'm stumped. If the lines are no long lined up, you need to have the prop rebuilt or invest in a new one. Unusual failure on a new prop. Let us know what you find.

 

[duck64]

Re: Problem with my new Johnson....

I have a Johnson 15hp and I believe it's a 2001 or 2002.

It had NEVER been used until 2 weekends ago. Never even seen gas or been tested.

First weekend on the lake everything worked great...

Then last weekend it was running fine for the first hour or two, then there was a little more smoke than usual coming out of it (especially in reverse). Didn't think anything of it.

Then a few hours later it pretty much died. The motor was running, but the fastest it would go was slower than trolling speed. The prop was barely turning. I noticed alot of smoke and black tar colored 'gunk' coming out of the hole where the exhaust is....

Anyone have any idea why this would happen to what is technically a brand new engine?