SOS 300 HPDI bent spark plug

Bogart · 10-04-2008, 12:25 AM

was fishing when I hit some submerged wood
and spun a hub had a spare crappy aluminum prop
went fishing port motor was 200rpm off because prop was not the same pitch
I took it real easy 24 knots instead of 30 trip went great Mucho tunas
got back to the break wall when port motor ran real ruff was going 12 knots because it was dark limped in pull the plugs to find the # 1 cylinder spark plug was bent
motor idles fine
but when under load seem to buck like the motor wanted to jump out of the water
did I kill the Block Did something break and pass threw the cylinder
I don't have a compression gauge were do I start the diagnosis???

Thanks Bogii

Bogart · 10-04-2008, 11:16 AM

when I say bent plug the prong was bent into the center electrode and it looked chewed up.

Bogii

Ultralite · 10-04-2008, 01:10 PM

Shine a small light into the spark plug hole and look at your piston crown. If as you say it looks chewed up, you'll probably see damage on the piston crown. Here's hoping you find none.

Gringo · 10-04-2008, 01:38 PM

Isn't the only thing between the injectors and the cylinders the reed valves on those?

Bogart · 10-04-2008, 07:17 PM

Quote:

Originally Posted by Ultralite

Shine a small light into the spark plug hole and look at your piston crown. If as you say it looks chewed up, you'll probably see damage on the piston crown. Here's hoping you find none.

I dont see any damamage on the Crown??????
just bought a pressure tester
will let you guys know the PSI asap

Bogii

Gringo · 10-04-2008, 07:47 PM

busted ring could do that, too...

uhhh....is the piston going up and down when you crank it over?

Bogart · 10-04-2008, 08:04 PM

Yes motor runs fine then goes real ruff at load
flying back to mexico tommorow with pressure gauge will advise

Gringo · 10-04-2008, 08:17 PM

well, SOMEthing regapped your plug...

I was wondering if, when you were looking into the cylinder, you tried turning the engine over to see if that piston moved. You said you spun a hub...was wondering if a wrist pin or connecting rod let go.

It could run on five cylinders at idle, right? Something would be making a racket at some speed though.

tunatango123 · 10-04-2008, 11:46 PM

with all the problems they had with the 300 hpdi power heads I hope it is something else for your sake. I am wondering if you tore the lower unit up that would cause it to run rough when under a load.

jawz12 · 10-06-2008, 03:50 PM

not good...you've got a blown power head-that cylinder has detonated...

10-04-2008, 12:25 AM	#1
Bogart Guppy Breeder Join Date: Feb 2008 Posts: 30 Credits: 1,356.7	SOS 300 HPDI bent spark plug was fishing when I hit some submerged wood and spun a hub had a spare crappy aluminum prop went fishing port motor was 200rpm off because prop was not the same pitch I took it real easy 24 knots instead of 30 trip went great Mucho tunas got back to the break wall when port motor ran real ruff was going 12 knots because it was dark limped in pull the plugs to find the # 1 cylinder spark plug was bent motor idles fine but when under load seem to buck like the motor wanted to jump out of the water did I kill the Block Did something break and pass threw the cylinder I don't have a compression gauge were do I start the diagnosis??? Thanks Bogii Last edited by Bogart; 10-04-2008 at 12:32 AM.

10-04-2008, 01:38 PM	#4
Gringo I think Admin is going to let me have this space Join Date: Dec 2007 Location: 21.9 deg. N Posts: 1,367 Credits: 2,628.8 Boat: Contender 25 Home Port: Providenciales TCI BWI Best Catch: This girl who shoots the monkeys off my back. Occupation: Perfecting the art of the 7 day weekend.	Isn't the only thing between the injectors and the cylinders the reed valves on those? __________________ http://2gringos.blogspot.com/ There are very few personal problems that cannot be resolved with the proper application of high explosives.

10-04-2008, 07:47 PM	#6
Gringo I think Admin is going to let me have this space Join Date: Dec 2007 Location: 21.9 deg. N Posts: 1,367 Credits: 2,628.8 Boat: Contender 25 Home Port: Providenciales TCI BWI Best Catch: This girl who shoots the monkeys off my back. Occupation: Perfecting the art of the 7 day weekend.	busted ring could do that, too... uhhh....is the piston going up and down when you crank it over? __________________ http://2gringos.blogspot.com/ There are very few personal problems that cannot be resolved with the proper application of high explosives.

10-04-2008, 08:17 PM	#8
Gringo I think Admin is going to let me have this space Join Date: Dec 2007 Location: 21.9 deg. N Posts: 1,367 Credits: 2,628.8 Boat: Contender 25 Home Port: Providenciales TCI BWI Best Catch: This girl who shoots the monkeys off my back. Occupation: Perfecting the art of the 7 day weekend.	well, SOMEthing regapped your plug... I was wondering if, when you were looking into the cylinder, you tried turning the engine over to see if that piston moved. You said you spun a hub...was wondering if a wrist pin or connecting rod let go. It could run on five cylinders at idle, right? Something would be making a racket at some speed though. __________________ http://2gringos.blogspot.com/ There are very few personal problems that cannot be resolved with the proper application of high explosives.

10-04-2008, 11:46 PM	#9
tunatango123 Salon puppy Join Date: Jul 2006 Location: Fair Haven, NJ Posts: 110 Credits: 1,418.1 Occupation: HVAC	with all the problems they had with the 300 hpdi power heads I hope it is something else for your sake. I am wondering if you tore the lower unit up that would cause it to run rough when under a load. __________________ Billy the kid 34 yellowfin triple yamaha 250fs captbilly@canyonrunner.com

10-04-2008, 11:16 AM	#2
Bogart Guppy Breeder Join Date: Feb 2008 Posts: 30 Credits: 1,356.7	when I say bent plug the prong was bent into the center electrode and it looked chewed up. Bogii

10-04-2008, 01:10 PM	#3
Ultralite Hide- My Wifes Logged On Join Date: Jul 2008 Posts: 158 Credits: 1,634.1	Shine a small light into the spark plug hole and look at your piston crown. If as you say it looks chewed up, you'll probably see damage on the piston crown. Here's hoping you find none.

10-04-2008, 08:04 PM	#7
Bogart Guppy Breeder Join Date: Feb 2008 Posts: 30 Credits: 1,356.7	Yes motor runs fine then goes real ruff at load flying back to mexico tommorow with pressure gauge will advise

10-06-2008, 03:50 PM	#10
jawz12 I think Admin is going to let me have this space Join Date: Jul 2005 Location: cape may nj Posts: 1,132 Credits: 2,035.9 Boat: 23 sea craft Home Port: cape may nj Best Catch: my dog jawz... Occupation: king of marine repair...	not good...you've got a blown power head-that cylinder has detonated... __________________ jimmy's marine service llc www.jimmysmarineservice.com jimmysmarineservice@comcast.net "jawz" is my dog....... cockpit monkey wannabe.... "don't try this at home..i'm a professional".... buyer's broker-found a boat you're interested in purchasing ? give a call,hull and engine check outs are available.consultation services also available.

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