Stripped out oil check hole...done right

mxracernumber1 · Jul 9, 2009

I know there has been lots of talk about this in the past, but since no one has ever really documented it, I'm going to take a swing at it. If swapping your outer case for one of those fancy red aftermarket ones with a sight glass (and a bunch of your greenbacks) is not the option you pick, here is the correct fix for this problem. My bike came from the factory with a Helicoil-type thread insert installed in the oil level check hole (weep hole in layman's). As the combination of me + 95 deg. summer days and near 100% humidity destroy oil faster than King Abdullah Bin Abdul Aziz can make it, I change my oil a lot. Now, I know that there are some folks that measure it out and put in the reccommended amount and never use the check bolt, but I grew up changing oil on a YZ125 and that's just the way I do it. Fact is, it took me nearly 2 years to tear-out that helicoil. Most likely, it will take another 2 years to tear out this one, at which point in time, I will either buy the fancy high-dollar case with the sight window or the bike will already have a new owner. If Husky comes out with a new 2-banger engine anytime soon (not that there's anything wrong with the current one) I will have enough of an excuse to buy a new WR-300 and won't have to worry about it anyway.

With all that out of the way, if you're stripped out and don't want to pay for the fancy cover, or your dealer $400 to do this, here's how it goes down. Takes about 20 min. to tear-down and about the same to put it back together.

Step 1: Make sure everything around the perimeter of your side cover is clean. I never put my bike up dirty. If I have a really nasty ride, I wash the crust off before I put it up, then I give it a thorough later on in the week, so it's almost never that dirty, but wipe down the perimeter around the side case very well. Make sure there's nothing than can fall off of something else when you open it either. Spend at least as much time cleaning around the side case as you do performing this fix. When it looks pretty clean, clean it some more.

Step 2: Drain the oil. Replace the plug immediately before you get into anything else. I can be easily forgotten when you're in "disassembly mode".

Step 3.) Remove the case-saver, brush guard, rock guard, whatever you call it-take it off. These bolts are hard to get to. You'll need a small 8mm driver. 5/16" works as well.

Step 4.) Remove kick starter. There is a single flat-head allen screw and a special alum. washer on the end of the shaft.

Step 5.) Remove the brake pedal. Remove the moutning bolt first (red arrow), then unhook the spring (green arrow). The piston comes out of the master cylinder with the pedal. It's kind of pointy and looks like you just brok something. Don't worry, it just fits up in there. Put the pedal in the bucket and keep moving.

Step 6.) Remove the oil line. The fitting is alum. so it's not going to feel like it's very tight. Remember that when you're puttin git back on. There are 2 alum. washers. Note that one is on top of and one is beneath the fitting. Screw the fitting back in to keep from loosing it or the washers.

Step 7.) Removed the oil filter cap. There is one really long bolt (red arrow). This bolt is part of the bolt array that holds the case to the engine, so it's got to come out anyway. If you don't want to remove the filter, just take out the long bolt, but if you haven't replaced the filter in a while, now is a good time to do so. I did, so I removed the entire filter cover.

Step 8.) Remove the clutch cover. You don't have to do this to get the outer case off, but you need to remove it at some point. It sticks up high enough that it will be difficult to retap the hole if it's not removed. See pic below.

Step 9.) Now you can start to unbolt the outer case. There is one screw out of all of these that in longer than the rest. Mark this hole (red arrow) with a Shaprie to remind you where it goes during reassembly, or you could drive yourself nuts wasting time trying to find the right hole.

Step 10.) Remove all the bolts from around the perimeter of the outercase. They're not torques especially tight so the socket driver will suffice for removing them. Pull the case off straight. Admire the beauty of the work that all that $9/quart Thumperlube has been doing for your engine-clean as a vissel! There are 2 o-rings here. Mine probably did not need replacing, but they've been in there for nearly 2 years and I had it open anyways, so I replaced them (green arrows, red arrow is the locating dowel). The smaller one is not in the pic. I had already removed it when I remembered to take the shot. These seal the flow of oil to the channels in the outer case. They're cheap-you're right there at 'em anyway, so replace them.

Step 11.) Now that we're off the bike, we can see the striped out hole (red arrow). Notice how close the hole is to the clutch cover (green arrows). This, plus the hieght of the cover make it hard to tap with the cover on. Get it off.

Step 12.) Drill out and tap for an M8 X 1.25 thread insert. Wether you use a Helicoil, Timesert or whatever, doesn't matter. Follow the directions for tap-drill size for the insert that came with the kit. You're not going to want to do this by hand you need a milling machine to keep it square, so if you don't have one, take it to your local machine shop like I did. I can do this myself, but it takes me longer to find everything I need in my buddy's machine shop than it does to do the work, so I just let him do it. Plus, he did it for free. My advice would be to just let them do it. It should not cost you more than $30.00.

Step 13.) You're going to need a M8 X 1.25 X 8mm long socket head cap screw. I ordered a bag of them from McMaster-Kerr in stainless steel along with a bag of stainless lock washers. Cost me $15.00 delivered. I don't know what to do with the rest of them, but I didn't know what I'd do with one of them until I needed it. Just keep them, you'll need them for something later, or just ask me and I'll mail you a couple of mine. By the way, you have to have a socket head cap screw and the washer that fits it because a hex-head is too big to go beside the clutch cover. The bolt is part# 101-02-10-03A206. THe washer is part# 101-02-05-72A132.

Don't forget the Gasket and o-rings. Hall's has them in stock. They'll run you about $30.00 altogether. Don't even THINK about using the old gasket. Remember-we're doing this properly.

Gasket part#: 8000 A5906 (table 10)
O-ring part#: 8000-99855 (table 10)
O-ring part#: 8000-66525 (table 12)

Step 14.) Put it all back together. When reinstalling the gasket, align it properly with the dowels on the engine. There is one dowel in the engine. Most likely, the other is still in the outer case. Not to worry. Align it as well as you can. Replace the o-rings, wetting them with a little engine oil to make them stay in place. There is a bushing on the kickstarter shaft. This bushing has a slot in it. That slot has to go over the spring where the spring goes into the shaft. If the slot in the bushing isn't properly located over the spring, the case will not go on. See pics below. In this pic, it was hard to see the slot becuase my wife's old crappy camera just washed it out with the flash, so I drew it in to make it vivible. I pulled it out some so it could be seen.

Here's another look. Sorry for the photo quality, but at least you'll know where to look. Bushing is all the way in-in the installed position.

Go ahead and screw the bolt into the oil level check hole. It sticks out just a bit on the inside. No, it will not hit anything.

Align the case with the dowel holes and the gasket. Slide it over the kick starter shaft. If it's properly aligned, you'll be able to push it nearly all the way closed without any mallets or bumping. If it's right, it wil go up flush.

You can torque the bolts to spec. if you like. Do not just tighten them with a socket. Chances are your socket doesn't fit anyway-that's why I'm using the driver. Hand-tight with the driver is good enough. Remember the long bolt goes in the hole you marked on the case. Put this one in first to avoid confusion. Snug all the bolts in a circular manner, then go around again tightening hand-tight.

Step 15.) Put the extra-long case bolt back in the oil filter cover. Hand-tighten with the driver.

Step 16.) Reattach the oil line. Remember, one washer underneath the fitting-one on top. Reinstall the clutch cover. I sanded the grunge off of the case where the clutch cover bolts up before I reinstalled the case. It looked as if it would help reseal the clutch cover to get that crap off of there. I did not replace the clutch cover seal. It's easy to get to later if need be and a little leak is easily noticable. Just make sure the sealing surface there is clean and any grit wiped away before resintalling the outer case. Hnad-tighten with the driver.

Step 17.) Reinstall brake pedal and kickstarter. Don't forget the rock guard.

Step 18.) PUT OIL IN THE ENGINE!!! Don't forget this step. If you want the inside of your engine to look like mine after 2 years and you live and ride in some extremely hot weather, use Thumperlube 20W-50. Spend the $9.00/quart. Afterall, you just saved yourself about $300.00.

So, if you're not slobbering on your keyboard with little button indentions in your face at this point, I'll summarize as long as you're reading:

The short and long of this subject is-Don't be scared of a stripped hole. This job really isn't that bad. It seems like a lot when you're reading it, but (sadly) it would have taken the average reader as long to read this post as it would the average dirt-bike owner to do this mod. 20 minutes to take off, get it tapped, 20 minutes to reinstall. Don't be afraid to do this yourself. Take it apart on Monday and order your parts. Get it retapped, get your parts on Thursday, reassemble Friday evening and be ready to ride on Saturday. Hope this was useful to someone. Now, I' must digress before I wind up slobbering on my keyboard with red button indentions on my forehead.