Buying a bike with a left cracked case... What I should know before repair?

[dakynz]

Hi guys, I'm helping my brother out on this purchase and will be the mechanic on this fix. Basically there is a steal on a bike, a 2007 YZ450 for cheap. Only problem is that it has a cracked case where the clutch assembly goes into the left side of the case. It definitely will need a new case and not a JB weld fix. Other then that the bike is pretty mint.

So here's what I need to know. First, is it worth it. The bike is about $2000 bucks and a new left case will be about $600. I want to do the job myself. What should I know before going into this???

Anyone that has done the left case replacement... please help me. I really need to know if this is a fairly easy job. I'm expecting to pull the engine, buy a manual etc. But I want to know if I just need a left case and gasket or is there more to this.

Please help... Really want to help my younger bro out but would hate to make this purchase and not be able to fix it.

[426 NOOB]

Hi guys, I'm helping my brother out on this purchase and will be the mechanic on this fix. Basically there is a steal on a bike, a 2007 YZ450 for cheap. Only problem is that it has a cracked case where the clutch assembly goes into the left side of the case. It definitely will need a new case and not a JB weld fix. Other then that the bike is pretty mint.

So here's what I need to know. First, is it worth it. The bike is about $2000 bucks and a new left case will be about $600. I want to do the job myself. What should I know before going into this???

Anyone that has done the left case replacement... please help me. I really need to know if this is a fairly easy job. I'm expecting to pull the engine, buy a manual etc. But I want to know if I just need a left case and gasket or is there more to this.

Please help... Really want to help my younger bro out but would hate to make this purchase and not be able to fix it.

from what I understand yamaha only sells cases as a complete set because of the way they are machined. One side that is new may leak when bolted up to the old one due to deformities that one may have and the other doesnt. When bought as a set they are exact.

[grayracer513]

Both crankcases do have to be replaced as a pair, and it is because they are machined as a set, but it has to do with the fact that the shaft bores are all cut at the same time so that they are perfectly square with each other. They are only sold in pairs, and if the dealer gave you a price, that's what it was for.

It is nearly as big a job as can be done on the engine, as you will be completely disassembling everything other than the head, carb, crank, and trans shafts. Take your time.

[MXKyle]

I had problems getting some of the bearings out of the old case halves. Be prepared to either buy some new bearings or the special tools required to get the old bearings out.

I actually tried to cut the bearings out of the cases after I threw a chain on my '03 but I found it impossible to clean out all the aluminum filings and bought new bearings anyway. Maybe you can do a better job than I did. Or when you get to that stage post here and someone may have some tricks that I didn't know about.

At any rate changing the cases isn't any more difficult than it was with any other bike until you start aligning the cam chains as you are putting it back together. Take special care to get the right index marks where they belong and you wont have any problems with that either. FOLLOW THE MANUAL!

KT

[dakynz]

thanks guys, appreciate the feedback and I'm definitely uncertain. I feel mechanically inclinded and have done everything on my bikes for the last 3-4 years. However, I've never done a engine out procedure though. This sounds like it has a potential do be a bad experience. If I already owned the bike I would do it in a second because I'm all about doing it all on my own. But be it its a new to me bike, its quite a risk at the tune of close to 2800 bucks.

[grayracer513]

If you're saying he wants $2800 for it with the broken case, he's delirious. If you're saying that's what you think you'll have in it when the smoke clears, it's a good deal.

You should be able to find a good running '07 for $3500 or less these days. If you take out $650 for the cases, and cover the incidentals with another $250, you're looking at $900. Your labor is worth something, because the only substitute for it is contracted professional labor, so add another $500 to be charitable, and you've got a used bike with a $1400 dent in it, making it worth no more than $2100, tops. If he won't go $2000, pass on it.

[dakynz]

If you're saying he wants $2800 for it with the broken case, he's delirious. If you're saying that's what you think you'll have in it when the smoke clears, it's a good deal.

You should be able to find a good running '07 for $3500 or less these days. If you take out $650 for the cases, and cover the incidentals with another $250, you're looking at $900. Your labor is worth something, because the only substitute for it is contracted professional labor, so add another $500 to be charitable, and you've got a used bike with a $1400 dent in it, making it worth no more than $2100, tops. If he won't go $2000, pass on it.

Actual asking cost is $2000 + new cases.

I think with talk and cash it could be $1500-$1800 for the bike not including cases. Your right though, my time although cheaper then a professional shop is definitely worth something.

Talked to my brother and we both are feeling tentative. Craiglist's search is underway to see what else is out there for comparison at the same price range.

[dakynz]

bro just emailed. 2007 450r for $3500. Never been raced.

[TIG88]

I say buy the bike. You said you would do it anyway, if it was your bike. This would be a good learning experience for the both of you.

[mike_dean]

I'd be a little worried that the bike was not run after the cases broke or something else in the engine was not damaged. You more than likely have not heard the engine run, or whether it has all the gears, I wouldn't spend more than 1500 for a non running broken bike.

[dakynz]

i have not heard it run. So it is definitely a risk. The guy that is selling it is quit the racer so the bike has probably been ran hard as well

[ace402]

I'd be a little worried that the bike was not run after the cases broke or something else in the engine was not damaged. You more than likely have not heard the engine run, or whether it has all the gears, I wouldn't spend more than 1500 for a non running broken bike.

+1 ?