50HP 2000/June Johnson..a rattle..

[Osprey165]

I was headed in after trolling (sweet water only) when I pushed it to 4500 rpm and she shut down. It restarted after a few tries but when I was pushing throttle I could hear a rattling of sorts from below the power head to the lower unit in that cowling/shaft housing. I kept it below 3k and made it in. I did power onto trailer. Never had any issues before this. Have had boat for 3 years. All I do is troll or anchor only and run it in the Susquehanna river for flatheads and walleyes.
Any ideas?
I went to the local marina and they told me that yr/make know to go "rattle rattle BOOM" ... yikes!
This engine does NOT have 500 hrs on it.
Are there < 7k new Johnson engines out there?
That marina are strictly Merc dealers although they work on all things.
I rather keep controls unless that is a minor cost to replace.

 

[Bosunsmate]

Re: 50HP 2000/June Johnson..a rattle..

look in cylinders for any damage to walls. compression test too
if thats ok inspect lu fluid

 

[boobie]

Re: 50HP 2000/June Johnson..a rattle..

It could also be the lower unit making the noise. Check it for any water.

 

[phillnjack2]

Re: 50HP 2000/June Johnson..a rattle..

Before getting too worried have a look at where the gear shift rod goes through the pan underthe engine, if the rubber grommet has come out it could simply be vibrating against the side and in this area would be making a loud sound due to it being like an echo chamber
I hope its something simple like this for you.
noises on outboard engines can travel and make you think they are coming from all sorts of places.
have you taken off the plastic bit just under the engine pan and had a look for anything that might have dropped down there and be rattling at certain revs ?
I would have a good look around before thinking the worst case scenario's.

its worth a look

phill

 

[Osprey165]

Re: 50HP 2000/June Johnson..a rattle..

Thanks I will chk for that grommet.

Lower unit oil was changed before I went on water nothing abnormal.

Compression check today and a look see at cylinder walls.

 

[Osprey165]

Re: 50HP 2000/June Johnson..a rattle..

Well I have piston material all over spark plug and 40psi compression in bottom cylinder.
More than likely octance issue/detonation.
I even used higher grade fuels with additives. These ethanol fuels are killing these older 2 cycles. And these 2000 engines, per manual, was designed for these ethanol fuels..ya right.
Time for a rebuild obviously. Like the than told me ' those engines are known to go rattle rattle BANG! '

 

[Bosunsmate]

Re: 50HP 2000/June Johnson..a rattle..

Lucky you could get it back on to trailer.
Yep pull it apart and have an inspection, might be rings or bearings, maybe you can get away with just a cylinder hone
post an update when you can as itl be interesting to know