careless mistakes piss me ooooooffffff!

[Paul_E_D]

So I re-shimmed my valves, put the cams back in, remeasured, and I swapped the intake shims. No biggie, I pull the cam again, swap the shims, and now comes the careless part. I put the cam cap half rings in backwards and as I'm slowly torquing the one piece cam cap down...snap. the thin bridge of the cap cracks before I even realized it wasn't seating in one corner.



I hate when I do stupid shit like this!

[Kitt]

sucks dude!

[Paul_E_D]

Ugh, this could be costly. I think the cam caps and head are matched! Don't know what I'm gonna be able to do here... might have to get it welded, but that could be risky. The thing brake with barely any force, but it was twisting, sooo...

[butcher bergs]

Rut-ro.

Which bike?

[Paul_E_D]

KX250F. Looking at the part, the only function the bridge has is to hold the cover down. It just has a hairline fracture near the threaded boss for the cover. It should not impact the cams in any way. Those areas are bolted as if they were were individual caps. I may just have to jbweld the crack to prevent vibration damage and run it. It's easy enough to keep an eye on it.

[SSearchVT]

Can you cut into the hairline and have it welded - using the head as a fixture to hold it in the right alignment? If the cam lobes are between the caps there is a very small chance that under high load the bridges keep the bearing caps from flexing.

[butcher bergs]

Clean them up very well. Cast aluminum is porus.

[lrrs313]

Ouch. I feel your pain; unfortunately I've made more than my share of similar "stupid" mistakes, trying to work a little too quickly.

[Paul_E_D]

Yeah, I imagine the bridge adds some rigidity. I'm seriously depressed. Might need a whole new head... Gonna have to call a specialist on this one.

[Danz19899]

my mistake wasn't quite as bad as that but I relocated my rectifier. I had to extend a few wires and did them up quick with some shitty connectors since I didn't have a soldering Iron at the time. Well 2 rides later connections got lose causing high resistance causing my rectifier to overheat and die.

So one break down and $130 later that lesson was learned. Got a sweet soldering iron now!!

[AimlessMoto]

That sucks buddy...

I just had a rut-ro myself while working on the tiger... put an o-ring that was slightly too thick in a very tight area and snapped a mouting bracket for my EVAP system.

Should be OK... JB'd it back on... it needs to be a super tight seal.

We'll see.

Check e-bay for your part... or even Bike Bandit. You can have the new piece matched if needed... better safe than sorry(er).

[Paul_E_D]

They don't sell the cap separate from the head...

[typeone]

damn, dude! hope you get better news from a specialist. how much is a new head?

[Paul_E_D]

5 hundo. I'm still of the mind that this can be fixed. Gotta make a few calls.

[typeone]

ouch! hope it works out

[Ken C]

Sucks.

[beet]

So I re-shimmed my valves, put the cams back in, remeasured, and I swapped the intake shims. No biggie, I pull the cam again, swap the shims, and now comes the careless part. I put the cam cap half rings in backwards and as I'm slowly torquing the one piece cam cap down...snap. the thin bridge of the cap cracks before I even realized it wasn't seating in one corner.



I hate when I do stupid shit like this!

The old "tick" WTF sucks!

[Paul_E_D]

My only hope is that cam caps aren't really under very much load. The area were the caps bolt to the head is unaffected. Just the bridge between the 2 sides. I think it's function is just to bolt up the valve cover.

If it does provide any kind of rigidity, there are two bridges, so a repair on one of the two should have negligible effects

[STREET&COMP]

A piece of info for you guys if you see a top end gasket like this, the head and the cam caps are machined as one piece, drilled into then cut. The half circles are the point of entry for the drill.

[STREET&COMP]

My only hope is that cam caps aren't really under very much load. The area were the caps bolt to the head is unaffected. Just the bridge between the 2 sides. I think it's function is just to bolt up the valve cover.

If it does provide any kind of rigidity, there are two bridges, so a repair on one of the two should have negligible effects

Paul take a picture of the cap, so we can take a look at the crack and it's location.

[Paul_E_D]

I'll try, but you may not be able to see it as it is very fine and closed tight. It is in the center of the bridge next to the threaded boss for the cover bolt.

[Paul_E_D]

OK, here it is with some brilliant paint work to show where the crack is.


Without artwork:

[butcher bergs]

Run it, just don't crank down on your valve cover bolts.

EDIT: I would at least spend some time to JB Weld it tho.

[Kurlon]

http://cgi.ebay.com/ebaymotors/KX250...s#ht_500wt_836

Looks like the cam caps are two piece though... might be cheap enough to monkey with?

[Paul_E_D]

I'm with ya. Just trying to decide if I should epoxy it. I was thinking a layer underneath and a layer on top might be enough to fully stabilize it. Or perhaps embeding a fine screen in the epoxy (like mini rebar)

edit: wow, the timing in the thread is out.