crf250 10 snapped proX connection rod

[mattila]

40 hours hard driving, not any warning siqns , oil changes 1-2 hours

http://imageshack.us/photo/my-images/534/img9181g.jpg/

http://imageshack.us/photo/my-images/199/img9185p.jpg/

http://imageshack.us/photo/my-images/823/img9194.jpg/

http://imageshack.us/photo/my-images/823/img9194.jpg/

[Berm-Saw]

wow that looks bad, no doubt about it your gonna need a new cylinder and piston! how is the crankcase? did your top end survive?

[Charlie C]

I feel your pain. Been there before. Check this one out. 09 CRF450.

https://www.thumpertalk.com/forum/showthread.php?t=910275&highlight=

[mattila]

thank god cases didnt crack , in top end exhaust valves and sparkplug went only.i was sure its gonna take whole new engine cause it blew in full throttle in 3gear , your pics looks so much worse and expensive charlie!

[Ron Hamp]

like smokey use to say pay a little now or a lot later

[Charlie C]

like smokey use to say pay a little now or a lot later

Ron, I'd be willing to bet there's only a handful of people that know who Smokey is! You're showing your age buddy, but so am I!

Smokey Yunick.

[Ron Hamp]

30 + years of building 4 stroke race motors from road racing to dirt track singles way before the evolution of 4 stroke mx bikes and i think i would be safe in saying way before any of the top 4 stroke engine builders curently building 4 stroke engines for top riders .So yes im showing my age and Smoky yunick was the man Smoky actually spoke with me and a freind of mine very aproachable person always had a story remind you of somebody .Eric Gore gave me the compliment of a life time this past winter @ the dealer show we were discussing a book that i was supose to be involved in and they wanted to use my name to market it i refused because of the content of the book it was sugested that i wright my own book because i have an editor and a company to publish it And Eric said do it your like the Smoky Unick of motorcycles thats putting me on a pedestal a little higher than i see myself but a very nice compliment.every one should read Smokys books.

[36MotoMarc]

And Eric said do it your like the Smoky Unick of motorcycles thats putting me on a pedestal a little higher than i see myself but a very nice compliment.every one should read Smokys books.

And coming from EG that is a huge compliment as he has a huge following and successfull business here in the rustbelt.

[Charlie C]

?

thank god cases didnt crack , in top end exhaust valves and sparkplug went only.i was sure its gonna take whole new engine cause it blew in full throttle in 3gear , your pics looks so much worse and expensive charlie!

It was both, but that's what happens when a connecting rod breaks. Luckily, it happend after my kid landed a 120' jump and not at the face! I'll never forget the sound it made. After I seen what happened, I made a different sound.

[mattila]

?

It was both, but that's what happens when a connecting rod breaks. Luckily, it happend after my kid landed a 120' jump and not at the face! I'll never forget the sound it made. After I seen what happened, I made a different sound.

wow after 120ft! gnarly thing seriously. i can imagine that sound. my rod breaks 2secs before 90ft double luckily it stops before the lip.

[Charlie C]

wow after 120ft! gnarly thing seriously. i can imagine that sound. my rod breaks 2secs before 90ft double luckily it stops before the lip.

That had to be a scary feeling.

[woodswpn]

I did not need to see that!

[Charlie C]

I did not need to see that!

Sorry!

[woodswpn]

Its okay-luckily I am not a hard core racer. Its just amazing to see that much damage.

[Charlie C]

Absolutely no sign of fatigue either. Just had the top end off and the engine was spotless inside. No play in the rod at all. I wasn't going to pull it apart until 100 hrs but I wanted to see how it was holding up. Had around 80 hrs on it so I installed a new CP piston and that was it. Boom it went a few hours later. I priced out the parts to rebuild it and it came in around 1200 my cost. I found a bottom end that was "Kevin Windham's" practice bike engine without the top end for 1200. I didn't but it from Kevin Windham so I don't believe it. Had a complete Hinson clutch kit with the Hinson cover, Boyseen water pump and a bunch of cool other stuff with it. I couldn't see rebuilding the blown engine for that amount of money when I can buy a complete bottom end for the same amount. It supposably had less than 10 hrs on it when I bought it. No proof of anything, so it is what it is. Still running strong!

[woodswpn]

So maybe a guy should just go ahead and do the crank/rod assembly and the piston all at once, depending on the hours and type of riding. The crank assemblies seem relatively cheap. Granted, it is a lot more work as well.

[Charlie C]

On a 250 if you ride the hell out of it, I'd look at 60-80 hrs. Trail riding and just beating around, 100+. Different stories from different folks, but I've heard of some people getting as high as 250 hrs with the stock crank and as little as 10 hrs also. Where you stand is anyones guess. There's no telling. My kid ran the hell out of the 250 and I was usually changing the crank between 30-40 hrs. It usually went before 40.

[woodswpn]

Good info Charlie. Trail riding and beating around is what I do, although I do work the low end pretty hard. I am right around 100 hours, and although the bike runs perfect(except for the occasion starting issues)I think it is time to pop it open.

[ds66]

Any news on 2011 crf250r showing the same signs of breaking cranks?

[Charlie C]

From what I've seen and read, the 11 and 12's are holding up real good. I have yet to change a crank in an 11 yet. They've been out for some time now and no bad news to report from my end!