Can't believe what was in the exhaust port!

[bucket235]

Took my boat in to have a noise in my lower unit checked out. they found this chunk of aluminum in the exhaust port. Immediately suspected a piston. Pulled the spark plugs and put a scope in. Nothing, pistions looked great. Compression was great. They ran it in the tank hard. Said it ran like a top with no unusual noises. Mechanic had never seen anything like it in 30+ years. he even called his retired mentor and he had no ideas. What the heck could it be? i don't want to tear down a perfectly good running motor. The only thing i could think of would be slag from the casting process on the exhaust side that finally broke loose.

 

[njrextreme]

Re: Can't believe what was in the exhaust port!

It looks to shiny for casting. Crazy!

 

[Fuzzytbay]

Re: Can't believe what was in the exhaust port!

Without looking at you motor it's possible its part of the pistion skirt, how it could have happend I don't know, but you should be able to look at the skirts through the exhaust port covers and see.

 

[R.Johnson]

Re: Can't believe what was in the exhaust port!

A piece of metal in an engine should not part company, or change place's. I would want to know where that came from. The engine may sound OK now, but something broke, or is starting to break up.

 

[Doernuth]

Re: Can't believe what was in the exhaust port!

If you found it in the lower could it be part of an annode?

 

[boobie]

Re: Can't believe what was in the exhaust port!

What's the Model # of the mtr ??

 

[jtexas]

Re: Can't believe what was in the exhaust port!

duh...it's a penny! sorry, couldn't resist.

Could it be a foreign object sucked in through the manifold? looks too big to fit through the reeds.

looks like aluminum, but is there any way to verify what material it is?

reminds me of an incident we had back in the 90's, a GE CT7-9 engine with less than 200 hours on a Saab 340B failed catastrophically just after take-off. The lab found an alloy foreign to the engine, but commonly used in the manufacture of tools.......

 

[njrextreme]

Re: Can't believe what was in the exhaust port!

Are you the original owner of the boat/motor? Maybe it was from a prior engine failure and never removed from the lower unit when rebuilt?

 

[lmuss53]

Re: Can't believe what was in the exhaust port!

It looks like tumbler media to me, or something that was floating around in the tumbler media. If they tumble the casting as part of the process it could work it's way into somewhere and hang there for years.

 

[bucket235]

Re: Can't believe what was in the exhaust port!

What's the Model # of the mtr ??

Its a E235TRLC18.

 

[bucket235]

Re: Can't believe what was in the exhaust port!

Are you the original owner of the boat/motor? Maybe it was from a prior engine failure and never removed from the lower unit when rebuilt?

good point. i'm not the original owner.

 

[bucket235]

Re: Can't believe what was in the exhaust port!

duh...it's a penny! sorry, couldn't resist.

Could it be a foreign object sucked in through the manifold? looks too big to fit through the reeds.

looks like aluminum, but is there any way to verify what material it is?

reminds me of an incident we had back in the 90's, a GE CT7-9 engine with less than 200 hours on a Saab 340B failed catastrophically just after take-off. The lab found an alloy foreign to the engine, but commonly used in the manufacture of tools.......

it must be aluminum. does not respond to a magnet.

 

[boobie]

Re: Can't believe what was in the exhaust port!

If you found this in the exhaust hsg of the g/c it could be part of a filler block that is under the exhaust cover on the back of the power head. I have seen those break up before and the chunks actually get caught in the prop. They were put in there to help mtr performance. On a v-6 you can get by with out them but on a v-4 " Bubble Back" if they weren't there you could burn a piston. If it was my mtr and everything else was ok I'd just keep on running it as it gets very costly to replace the filler blocks.

 

[Rick.]

Re: Can't believe what was in the exhaust port!

All is pure speculation. One thing for sure, you've got yourself a very interesting key chain. Rick.

 

[bucket235]

Re: Can't believe what was in the exhaust port!

Am I crazy for not tearing the motor apart? I think the shop wanted me to have them tear into it ($$) as they put "major powerhead damage may occur" on the ticket as a CYA. Are there any other tests I should do? What additional harm could be done by just running it until it dies? Other than blisters from rowing back to the dock.

Hopefully it will last years.

 

[boobie]

Re: Can't believe what was in the exhaust port!

Where EXACTLY was that piece of alum found and how did they find it ?

 

[bucket235]

Re: Can't believe what was in the exhaust port!

Where EXACTLY was that piece of alum found and how did they find it ?

it was sitting between the prop and the lower unit housing. i took it in with the complaint that i would get a "clunk" when putting it into gear, often killing the motor, like i had hit a stump. it would also make a ticking sound when in gear and prop turning. its obvious it was jambing in there as the back of the prop and face of the exhaust port is pretty chewed up.

thanks for all the help!

 

[boobie]

Re: Can't believe what was in the exhaust port!

As I said in a previous post it sounds to me like the filler blocks on the back of the power head have a piece broke off of them. Due to the age of the mtr do you want to spend some $$$$ on it or just keep running it? If it is filler block probs the worst that can happen is more chunks may break off and get stuck in the prop again. I just looked on BRP parts and the filler block kits go for around $570.00. Thats plus labor to repair and machine shop work. Not to be a smart *** but it's up to you.

 

[SKEETR]

Re: Can't believe what was in the exhaust port!

If you found this in the exhaust hsg of the g/c it could be part of a filler block that is under the exhaust cover on the back of the power head. I have seen those break up before and the chunks actually get caught in the prop. They were put in there to help mtr performance. On a v-6 you can get by with out them but on a v-4 " Bubble Back" if they weren't there you could burn a piston. If it was my mtr and everything else was ok I'd just keep on running it as it gets very costly to replace the filler blocks.

It has been suggested on this site before that removing the filler blocks would not effect anything and actually give an additional 100 rpm on a bubble back setup. How would removing them cause a burnt piston?

 

[Borchik]

Re: Can't believe what was in the exhaust port!

looks to me like a piece of an anode but i dont think they used them in 81, i am assuming its an 81 if the last 2 digits of your model number are IB instead of 18. I have also seen chunks of exhaust housings broken off and rolling around in the lower.