ISDE Aftermath

[GMP]

It is a little odd that it didn't squeak on the exhaust side more. Why does your PV look like its rusty (second pic down) ?

[SpeedyManiac]

There's a little bit of rust on the PV from shipping home from Chile. Must've been a bumpy/wet ride home, since any bare metal on the outside has surface rust. Doesn't look like the bottom end has affected.

Note: If you're ever shipping a bike by boat across an ocean, WD-40 all bare metal! My bike was fine going down to Chile, but coming home it got a lot of surface rust.

[PEB]

My bike gets some sort of oil after every ride/wash. It stays clean shiny and rust free that way.

Paul B

[widebear]

I would like to know what the differance in weight is between the various brands. vertex , wossner, wiseco .piston ,rings and pin

[SpeedyManiac]

I see. Well, mine is permanently with rings and minus a bit of material on the side so you won't get an accurate measurement.

I'd guess there's very little weight difference.

I don't usually spray down everything with WD-40 because I like to ride 3-4 (sometimes more) times a week. I don't have time to wash it every single time I go riding. Only for races and maintenance.

[gasgasman]

I honestly don't think you ran it lean.
The top of the piston is too clean.
When a bike is ran lean, it would start detonating which would start pitting the top of the piston.
The entire circumference of the piston would be scored up also.

If I was to guess, I would say the piston was out of round. Possibly mismachined.

[GMP]

That bike had a few hours on it before ISDE, right? I would think if the piston or clearance were at fault, it would have happened sooner.

I doubt splashing water would do it, everyone does that all the time. Plus the entire water jacket and warm coolant would act as an stabilizer.

Maybe it ran OK (not lean) most of the day and went lean suddenly, under load in the sand, heated up quick and seized. What did you do with the carb vent lines? Clogged with sand would affect venting and also could pull sand in and partially block the main jet. This has happened to me. Girrard is right the piston dome looks dark, like it was rich for awhile if anything.

Cooling system OK?

Just a few thoughts.

[SpeedyManiac]

I'll take a look at the carb vent lines.

I had maybe 2 hours on the top end before the start of the ISDE (I rebuilt it shortly before shipping, then had a bit of testing on it down in Chile). It had run flawlessly for over 7 hours during the day before it seized so I really doubt the piston clearance was an issue.

[widebear]

Originally Posted by SpeedyManiac

I'll take a look at the carb vent lines.

I had maybe 2 hours on the top end before the start of the ISDE (I rebuilt it shortly before shipping, then had a bit of testing on it down in Chile). It had run flawlessly for over 7 hours during the day before it seized so I really doubt the piston clearance was an issue.

You will never know if you dont check.The clearance may have been tight to start out with and not been a problem till an unexpected entered the equation. I'll bet as it stands your under 2 thou piston to wall clearance.

[SpeedyManiac]

I measured the clearance with the buggered piston/cylinder and it's at about 4 thou. Not extremely accurate with the scored cylinder/piston, but it gives a ballpark number. I can't remember what it was when the new top end was put in it before I sent it to Chile, but I know it was within spec.