engine knock

yes, I removed all plugs and turned it by hand, fine. also gave it some turns with the starter and moved fine, nothing strange according to my mechanic...

to this point my friend and mechanic, wants to check the head, fix it and put it again...and see what happens...
or should a i just remove the engine and see whats going on from below...

now why the knock? the blown gasket? or piston slap?

Seb, any news?

Kap,
It could have been bad gas!!
Last year I had the tips blown off 3 plugs from bad gas. Luckly my motor has a knock sensor and wouldn't let it go above I think it was 2,800 rpm.
Long story short I would hate to think what would have happened if I was able to run it at full rpm.

Oh by the way I was running Startron in the fuel at the time. I WON'T EVER BUY THAT CRAP AGAIN back to Stabil marine and no more problems.

Man! Kap you sure have had your share of problems this year. Cheer up..you will get it figured out. In the meantime I quess it is sun-bathing on the bow of your freinds cruiser. Seem to remember some good pics from past outings on the cruiser!

That sounds like a good plan. That may tell more than just tearing into it. Just the fact that it is still rotating is a good thing.

We had a Mastercraft way back when and it was bought brand new, it had a 200 hour warranty, at 211 hours we blew a hole about 1 1/2 inches in the center of a piston, had to replace the piston and we got it back up and running again. The theory was a lean condition. Later the whole top deck worked the pop rivets loose and detached from the bottom/hull. That was real special. That was when we went to a BFN. When the BFN had somewhere near 3000 hours we rebuilt it, on teardown the piston skirts were detached/broken off and being held in place by the rings. Willies Malibu detonated at 5200 rpms at 800 hrs and had major damages, hole in block from the rod into the water jacket...when I pulled the head there was no piston left the rod looked like a hammer had beat it for hours. Roy was driving and he said the sound was something he would not forget.

I've got my fingers crossed that yours will be a fairly minor repair, you may have caught it before the real bad stuff has happened.

kapla wrote: Engine ran sooo good, guess *************** happens...

Hay Kap,

   The 30 seconds before it lets go is always the best it EVER ran.
Keep your head up, ya know if we could wrench on it with you we would be there. Thats what makes this site that Keith created sooo cool.

(Thanks for bringing us together Keith - get well soon!)

   The 4 wide nats at Z Max dragway was last weekend.
Google "Mat Hegan explosion" hard to believe you could
live through that!!!

wow, auto bad words deleting!

looks like my back deeps will be put on hold until this is solved...

Knock under load, = rod bearing.
With low comp on #2 and bad plug, rip the haed off - fix what ya find.
Hard to guess, but when you pull the head you'll know.

        Good luck, hope it don't cost too much!

Well we will know when we know but heat/detonation/bad gas type issues is my best guess. You could have stuck a valve, dropped a seat, or cracked/blew up or melted a piston. A little too much timing and/or less than ideal gas can cause/facilitate any of those things. They can happen pretty quick or overtime at barefoot speeds and loads.

I'm hoping for the best outcome, after having 3 bad engines in a row I know the feeling all too well. Hopefully it turns out to be something minor.

take a long piece of pipe or a broom handle or long screw driver or a mechanics stethescope to listen and locate the source.

Good luck.

Check your flex plate...

Take it off, look at it very closely. You might see a very faint mark where it is arcing between 2 cylinders. If you have a new cap....you can throw it on.

Happened to me...thought my motor was toast!