'05 WR450F - Cracked Crankcase Assembly...NO!!!

Here is my sad, sad tale. Hopefully somebody at TT can help me at least figure out how sad it really is...

I'm out for my 6th or 7th ride on my new '05 WR450 (less than 200 miles on it) and having a serious blast with my ridin' buddies. We're riding up this semi-steep, yet deep sandy climb. Near the top, I hit one of the only sizeable rocks on the whole climb and bucks me off. The bike squirts forward and hits the only other rock on the whole hillside. No kidding. Anyway, I go to pick up the bike and oil is GOUTING out from the crankcase area just adjacent to the shifter arm. Uh Oh.

Anyway, we break the chain and tow back to the truck. Now, I've got a missing chunk of crankcase (about an inch diameter) just below where the shifter lever enters - it's as though the shifter lever torked DOWNWARD (think way overzelous downshift into 1st gear) and blew off part of the crankcase.

How screwed am I? I can send pics to any gurus who might give some advice, but I'm not sure if I can post the pics here. Any advice or thoughts would be welcome.

Sounds like my luck, pictures would realy help though to see how big of chunk is missing.

First of all; posting pix is easy. Just use one of the free digital photo storage sites on the web to upload images to and copy/paste the URL for your pic into the body of your post. The most important ? is....do you still have the chunk of case that came out of the engine? If so, then a good TIG weldor can patch it back in. If not, things get hairy. I've seen cases that have been repaired by slowly building up aluminum which has to be done slowly over time in order to keep from putting too much heat into the case, causing warpage. Oh, and method 2 requires splitting the cases and emptying them prior to the procedure. Gawd only knows what a replacement set of cases costs for a WR. That's how hosed you are.

$386.14 for the '03 cases from Zanotti ('05 probably the same). Probably similar from the TT store. I wouldn't repair the case unless you can do it with 100% confidence. Imagine how screwed you'd be if the case started leaking and you lost all the oil without knowing (similar to loosing the drain plug). Even to repair it (if you can) you're going to have to split the cases. Since you caught it before riding it further the damage at this point is limited to the cases and a few gaskets. Also the case halves are a matched set so don't try to replace just one side from a junker.

Ok, so looks like I need the 2 case "halves", gaskets... also some transmission stuff? It looks like the shift shaft is what really did the damage to the case - acting as a lever in tandem with the shift pedal when it struck the rock.

I will post the photos as mentioned above so there will be a visual...


The case halves come as a set so that price was for both. It looks like you'll probably need a shift shaft as well.

If your shifter shaft is bent, and it looks that way, make sure you measure the shift forks. They most probably will be bent too. If you remember what gear you were in when it happened check that fork well. If you don't get them right, you may eventually have trouble with the bike jumping out of gear because of worn dogs.

Shift forks are probably ok since they don't directly connect to the shift shaft though it certainly wouldn't hurt to check them out.

Hmmm. I posted my first reply before I saw the pix. Since the shift shaft ripped out the missing chunk of engine case; it should be assumed to be bent. A good TIG weldor now must also be a machinist to fix that mess. Yikes! I'll go with PBDBlue's recommendation to replace the cases. It's a pretty big job to replace the cases; and unless you've been down that road before (successfully) you might consider seeking out a Yamaha tech to do the job. It looks like one of those freak accidents that could've happend to any of us. You have my sympathy dude.

Thanks for the replies thus far guys. Yep, I'm bummed. But, sounds like it can be fixed - even if it needs to be fixed by a Yamaha Pro (read: spendy?).

Two obvious questions (for a neophyte such as meself):

First, (and I know this is asking for pure speculation) what's chances of the transmission being hammered vs. just the case and shift shaft?

Second, can you just buy a short block (cases with all internals in place like in an auto) and bolt THAT up to the top end? "My old man is a television repairman, he's got this ultimate set of tools. I can fix it." (Fast Times @ Ridgemont High)

My guess is that just the shift shaft that is bent. The transmission is pretty much a seperate component as the shift shaft only operates the shift drum and does not connect directly to any other transmission components. I bought my '03 with a grenaded motor in pieces in a box so I'm pretty intimate with the internals. As far as I know there is no short block option available.

The job CAN be done by the inexperienced...we've all got to learn somehow. Just take your time and follow the book. The book calls for bunches of special tools...you really don't need 'em. If you can't figure a way around 'em, post up here and we'll help you. The only things you'll need for sure (in addition to "normal" tools) are a flywheel puller, internal and external snap ring pliers, a ring compressor, and, if you don't have an impact gun and sockets, a clutch holding tool.

Also, check e-bay for cases. Sometimes ya get lucky for cheap!

I had a similar situation years ago. Before tearing the cases apart, I decided to try JB welding the broken piece to the case. It worked and ran for years after that. Assuming there's no internal damage, you may consider this option.

This topic brings up another question........ Insurance.

Years ago when I raced moto x, my race bike was stolen....I didn't have insurance on the bike and was just out the cost of the bike ($4000) back then.

Since getting back into biking, I have insured all of my machines.....would insurance cover this type of thing? If you were in your car and slid off of the road and hit a rock, this damage would be covered.

If it were on a boat, and you hit something that caused this type of damage....its covered.

What about a bike? and if thats the case (no pun intended) why don't more people insure their bikes? A $250 or $500 deductable isn't bad when faced with this kind of repair.

Good point. If you have comprehensive coverage I would think it would be covered as it was the result of an accident and not simply a mechanical failure.

This DOES bring up a good point. Homeowners insurance would not work for me in this case, would it? You'd have to buy accident insurance for the bike SPECIFICALLY, right?

Which brings me to my last question (for the time being): how much do you guys think this will run, "ballpark estimate"? Cases, Shift Shaft and Gaskets plus Labor? Has ANYBODY had to do a job like this specifically recently - what did it cost you?

Thanks again...

I am not sure about the cost but you might save some cash if you take the motor out yourself. If you know how to do a top end you can take that off and just give the guy the bottom end of the motor. The more work you can do the more you save. My previous bike was an XR400. I put a hole in the case and I think it cost about $700 but I had a buddy that is a mechanic do it for cheap and I replaced the bearing and top end too.

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