I guess by now everyone has figured out that I...

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cannondale27 · #11 Post by **cannondale27** » Sun Aug 13, 2006 4:42 am

No offense meant.We will all hopefully know as soon as he gets the crank out.Its amazing the destruction that can happen at the rpm's we are all doing.There were alot of YFZ breaking rods for awhile also.Most were caused just by the wristpin siezing even if just for an instant.Coolant is definitly immovable.I just cant buy detonation.That is not immovable and a motor can run with it for a very long time but it would show signs.Only thing odd I see is the wierd red color tone on the piston.Could a large amout of some type of trans fluid gotten into cylinder and caused a catastrophic hydrolock?Maybe.Or could be camera.But I see it on the rod also

mzavala · #12 Post by **mzavala** » Sun Aug 13, 2006 6:03 am

QUOTE (cannondale27 @ Aug 12 2006, 09:42 PM) <{POST_SNAPBACK}>

No offense meant.We will all hopefully know as soon as he gets the crank out.Its amazing the destruction that can happen at the rpm's we are all doing.There were alot of YFZ breaking rods for awhile also.Most were caused just by the wristpin siezing even if just for an instant.Coolant is definitly immovable.I just cant buy detonation.That is not immovable and a motor can run with it for a very long time but it would show signs.Only thing odd I see is the wierd red color tone on the piston.Could a large amout of some type of trans fluid gotten into cylinder and caused a catastrophic hydrolock?Maybe.Or could be camera.But I see it on the rod also

The actual color is kind of a copper color. In my case I really don't believe it was fuel or timing eventhough I not ruling it out yet (I would think I would have some kinda of ovious heat signs, something would have melted) . I'm attaching a pic of the crank if maybe somebody can tell me if the separation between gear & crank counter weight (flange) is normal or if that is maybe what cause it to spin out of time with the balance shaft. But if that happend it would have had to spun the 360 deg to end up in the roll pin hole because it seems to be perfectly lined up with the crank roll pin hole. I'm also getting a .022" play on the big end of the rod & the width of the crank is 2.5" with ruler since I don't have the correct size micrometer at this time. Also does anyone know if the counterweight on balance shaft is just pressed on to shaft because that what it looks like to me (I don't see any pin or other method to secure to shaft)

mzavala · #13 Post by **mzavala** » Sun Aug 13, 2006 7:24 am

Take a look at these pics, looks like I found the culprit! If you look at the timing marks in refrence with the counter-weight there is no way that you could even get the gears close to meshing because the counter-weight hits the big end of the rod(usually the weight is at opisite ends when the timing marks are aligned.

Now anyone have a deal for me on a whole bunch of engine parsts!

cannondale27 · #14 Post by **cannondale27** » Sun Aug 13, 2006 4:48 pm

Yup that did it.I believe they are pressed together but not sure if there is a keyway or something to hold it.Sure doesnt look like it.Never saw one spin before.Might be welding mine a bit from now on or green Loctite.Thank you for the great pics.There is a good chance that crank might be reusable with just a rod and z400 bearing.Timbo has both dont throw it away.Azcannon has a good deal on a motor.Wistech also.This timing is how it is supposed to be:

Happyboy · #15 Post by **Happyboy** » Sun Aug 13, 2006 5:46 pm

Mind if I ask how this was assembled? When you pulled the crank assembly out was it in time or was it off? Then I gotta ask if it was off who put it together?

mzavala · #16 Post by **mzavala** » Sun Aug 13, 2006 8:03 pm

QUOTE (Happyboy @ Aug 13 2006, 10:46 AM) <{POST_SNAPBACK}>

Mind if I ask how this was assembled? When you pulled the crank assembly out was it in time or was it off? Then I gotta ask if it was off who put it together?

It was in time from what I could tell because the counter weight of the balance shaft would hit the rod & using the counter weights as refrence (could not turn the full 360 degrees). I didn't take it apart in the usual manner, I separated the balnce shaft & crank shaft from the side plate so that I could peek inside before fully separating from the case. I put the engine together myself, which that would usually make me blame myself but when I took it apart I left the crank & balance shaft together with the plate. the reason being it had fairly low hours & the reason for the tear down was to weld the case because of my stupidiity of not doing the motor mount update.

cannondale27 · #17 Post by **cannondale27** » Sun Aug 13, 2006 8:43 pm

Happy how could he have moved the wieght on the counterbalancer?Or are you saying it was not lined up and then hit spinning the counterwieght?Thats possible.Have had to look twice on many installs when crank turned while in plate.Could easily happen.

mzavala · #18 Post by **mzavala** » Sun Aug 13, 2006 8:47 pm

QUOTE (cannondale27 @ Aug 13 2006, 01:43 PM) <{POST_SNAPBACK}>

Happy how could he have moved the wieght on the counterbalancer?Or are you saying it was not lined up and then hit spinning the counterwieght?Thats possible.Have had to look twice on many installs when crank turned while in plate.Could easily happen.

If that was the case wouldn't it had happend right away after putting it together?

cannondale27 · #19 Post by **cannondale27** » Sun Aug 13, 2006 8:59 pm

Yes you would think so.Is the rod main bearing good yet?No Up and Down movement?

mzavala · #20 Post by **mzavala** » Sun Aug 13, 2006 9:05 pm

QUOTE (cannondale27 @ Aug 13 2006, 01:59 PM) <{POST_SNAPBACK}>

Yes you would think so.Is the rod main bearing good yet?No Up and Down movement?

No doesn't seem to have any movement, But it has .0022" between the rod & crank at the big end of rod. Isn't that too much?