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kevgrn114

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"I appreciate everyone’s hel

"I appreciate everyone’s help on this board, it has help immensely so far.

So I finally manage to get the starter replaced and it sounds beautiful, starts first time, NICE

We get it out on the water and hook up with a friends party barge, we sit for a bit, then go back into the marina to pick someone else up and go back out to the barge, then after a while we make a run back to the marina to grab some food. The engine has been fine this whole time…
When we leave the dock this time to get back out to the barge, I start to accelerate past the wake buoy and the engine starts to sound really load like the exhaust is above the water or something and it is popping sporadically as we go, and the power is way lower than usual. All of the gauges on the dash are normal, oil pressure is between 40 or 50, temp is 140.
So, now my question, what would go out all of a sudden to cause this? Can a spark plug go out that quick? It seems like it is a valve issue or something along those lines…

As usual, any help is appreciated.

Kevin
1979 140 #1"
 
"Loud exhaust noise? Exhaust

"Loud exhaust noise? Exhaust manifold gasket, riser rubber coupler, cracked down pipe. Look and listen."
 
"Kevin,

Like Guy says, you

"Kevin,

Like Guy says, you need to find out where the noise is coming from and get back to us."
 
"ok, I pulled each spark plug

"ok, I pulled each spark plug as it was running to try to narrow things down. starting from the back of the boat the first and secong plug I pulled made no difference, the third and forth plug each killed the motor.
This made me wonder if those 2 back cylinders weren't firing. I replaced all of the spark plugs just to see if it would help. it still sounds the same.

The puttering sound I'm hearing seems to be coming from the carburator, it is louder over the top of the carb than over any of the cylider areas. I took a quick video to see if you guys could help identify the sound.
http://www.k-j-g.com:2082/viewer/home%2fkgreen%2fpublic_html%2fcustompaperpocket yachts%2fvipboat/MVI_1680.AVI

All of this happened all of a sudden while on the water, could it be something really easy like the fuel filter or something? I had just changed the starter before that last trip and I had to disconnect the fuel line from the fuel pump to get access, maybe someting got knocked loose and clogged the line?"
 
"Could be a hung intake valve.

"Could be a hung intake valve.
Try some seafoam or upper cylinder lube in the gas. Or dump a little directly into the carb while it is running preferably with some load.
If these are not handy, try some ATF.

has it been a while since this engine was last run?

Rod"
 
Try replacing the back two plu

Try replacing the back two plug wires since their removal made no difference.
 
"Sticky Valve or Head Gasket b

"Sticky Valve or Head Gasket blown between the 2 back cylinders, carry out a compression and a valve leakage test.
Cheers
Peter C"
 
"well, turns out out neighbor

"well, turns out out neighbor used to tool around a lot with hot rods and talked me into the engine a bit. The valve is stuck in the last cylinder, I have the head pulled and he is going to find someone he knows who can get it machined and things to get it all worked out. Hopefully thats it, at least for a while.
happy.gif


The rocker arm has a hole in it where the rod went through it so I guess I need to find a new one of those and get a gasket kit.

Well, on the plus side I am learning.
happy.gif
"
 
stuck from water intrusion??

stuck from water intrusion??
whats the condition of the riser?Any visable holes or was the exaust manifold wet?
 
Thats very weird that there is

Thats very weird that there is a hole in the rocker. Is this a high time engine?
Make sure you check the pushrod for straightness.

Rod
 
"The pushrod is still straight

"The pushrod is still straight, it poked up through the rocker arm, I assumed that was by design to prevent cam damage, dunno...
There is a little water in the pistons but That may have seeped in during disassembly. If not I assumenew gaskets on the head and exhaust manifold will help that?
And of course next question is where can I get the head gasket? I found the exhaust manifold gasket set."
 
"oh, while I have the exhaust

"oh, while I have the exhaust manifold and elbow all out in the open, what should I check for or do to clean it?"
 
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