Loud engine noise '01 XC 200

[RBrider]

I just returned form visiting dirt bike friends in Ohio, where I rode their semi secret 20+ mi enduro loop with them. Near the end of the ride, we had to do a steep hill climb with a slightly gnarly mid section. The kind where you stop at the top and wait to see if everyone makes it and lend a hand, if needed.

The XC 200 ran like top all day, cleared the hill climb and I pulled clear of the trail and shut it down to wait for the others.

After we got everyone up, I got back on, kicked the bike over, it fired then shut off suddenly. No noise, just shut off suddenly, as in , locked up. The kick start was solid, no movement at all.

I put the bike in 6th gear and rolled it backwards. The engine turned over easily in reverse, rolled it forward and it did the same.

Got back on and it fired right up but was making a terrible racket. It sounded and felt like the crank was broken or something.

We were so far back in the boonie's that I would've probably just pushed it off the trail and left it for dead if it quit running, but I clicked it in gear and all seemed fine except for the noise. The other guys worked with me to get it back to the truck. We just maintained a slow steady pace that didn't require me to rev the engine too much.

Suddenly, just before getting back to the truck, the noise stopped and all seemed fine. Like nothing had ever happened.

It has no oil leaks, coolant level is fine & the plug shows no damage and is a perfect shade of light brown.

At first I thought maybe the reed valve had broken and wedged it self betwen the crank and crankcase, but after doing a search on this forum, I suspect the crank stuffer bolt(s).

I just got home yestrday evening so I haven't dug into it yet. I'll report back on what I find when I dig into it.

RB

[pscook]

Mechanical clattering sound (like shaking a coffee can full of bolts), or exhaust/intake rattle? I'm interested to hear the issue, mechanical issues don't typically randomly resolve on their own. Intriguing. I'm thinking stuck power valve or stuck reeds, but intermittent issues are hard to trouble shoot.

[Neil E.]

The usual suspects would be:
1) loose primary nut
2) broken clutch plate
3) crank stuffer bolt

[Harry]

Mine made a horrible bucket of bolts noise when the main crank bearings went, due to corrosion from long term storage.

[RBrider]

Thanks for the tips, guys. I hope to start looking into it today.

RB

[gasgasman]

Originally Posted by Neil E.

The usual suspects would be:

3) crank stuffer bolt

+1
Pull the cylinder off and have a look see.

[RBrider]

Originally Posted by Harry

Mine made a horrible bucket of bolts noise when the main crank bearings went, due to corrosion from long term storage.

Mag side crank bearing went out. The cage came apart and damaged the piston and cylinder, too. Not bad, but enough that it'll take a new piston and re-plating.

Could of been worse, I guess.

RB