Cam woes, yes, I dropped something down there.

[shagsmc]

So I shim my valves currently last night on my 05 yz250f, carefully put everything back together. Started the bike in the basement, started second kick. Idled well, I wanted to rev it to make certain there was no valve chatter. As I start revving the engine the cam chain tensioner sheers off. The two 8mm bolts that I torqued to spec (8ft/lbs) sheered right in half while revving the engine. I was able to shut the bike down in time, took the valve cover and the timing chain did not skip (my markings were still in the proper place on the cam). Ok, thought to my self could simply be a defect of weakness in the bolts. I start removing the 3/4 piece of threads left in the engine and one falls right into the cam chain tensioner hole. I know realize I should of plugged that hole with a rag but I wasn't thinking.

I have a couple questions. If I can't get it out with a magnet I figure I'll pull the ignition cover and pull the rotor. Do I need to put the engine to TDC to take these apart, I am scared that piece of bolt might be between the chain and bottom sprocket maybe jamming or breaking something if I move anything around.

I was also thinking of taking the intake cam off, but again I am afraid of bringing the engine to TDC, if I only take the intake cam off and the not exhaust *if* I get that piece out would I be able to simple put the engine to TDC and put the intake cam back on?

Thanks in advance for any responses.

Edited March 24, 2010 by shagsmc
Forgot to add what bike I have.

[KJ790]

Pull the ignition cover off and take a look, you don't need to be at TDC to pull the stator off. It might be stuck to the magnet on the stator.

[shagsmc]

Thanks for the reply KJ790, appreciate the info.

I went out and got a stronger magnet and tried to fish it out again, got it out this time! I grabbed a snake cam from work, fished it along side the intake cam and I was able to see it and grabbed it with the magnet.

Now to sort out why this happened in the first place, seems like my torque wrench didn't break at the proper f/lbs, going to invest in a higher quality one, stupid powerfist!

[Spyder500r]

Nice save man.. it could have ended a hell of alot worse:thumbsup:

[mkporn]

Was the torque wrench you used for the tensioner bolts the same one you used for the cam bolts? If so, I would be a bit concerned if you think the wrench has issues and you overtightened the tensioner bpolts with this.............Yikes