Stripped and broken oil drain question.

[brandolph]

I've got a '97 RMX 250 with a broken case. :ugg:

I bought the bike used and the previous owner had drilled and tapped the oil drain from an 8mm to a 10mm. This left about 1mm of case around the "boss" or whatever you call the protrution that the drain bolt goes in. I've been EXTREMELY careful with the thing but last night when I changed the oil it gave up. Thought it was just stripped but when I tipped the bike over the "boss thing" has two vertical cracks in it. My dad's a machinest and a master welder and pretty much said I'm screwed. He said if I split the case he might be able to weld it up for a re-tap or helicoil but didn't seem too hopeful. Anyway my plan is to Mickey Mouse it back together to finish off the season, buy new cases (big :ugg:) and send the whole mess to E. Gorr this winter.

Now my question...About 1/2 of an inch up the drain hole is a passage that leads from inside the case to the outer clutch assembly.
Is this the only way oil can get from the clutch to the inner case??
It doesn't seem like the drain bolt blocked this passage.
In order to do a halfway decent job with any kind of filler, I'm going to have to plug up this little passage and don't know if I'll be able to drain the oil out of the case through the filler hole or if oil poured into the filler hole will get over to the inner case.

Hope somebody can help. Thanks.
Sorry this got so long. I like to type!

 

[svtrb]

Try this: have someone machine a new "boss" from aluminum round bar with a threaded hole machined in it. Drain oil, fill with water, weld boss on from outside over existing hole, flush out water, refill with gear oil, run for 5 min.,drain oil, repeat until oil looks fresh after draining. It might work.

 

[Ol'89r]

Brandolph.

That is pretty common on the RMX. I just did one like that last week.

If your dad has a heli-arc welder, it can be fixed and the cases don't have to be split.

First remove all of the broken pieces. Then grind the case back to clean metal. It's a good idea to stuff some grease in the hole so grindings don't get into the gearbox. Clean the area and brush it with a stainless brush until it is shiny bright in color.

Using low heat, build up the broken area with weld bead. Bead on top of bead, around the hole until you have built the entire area back up, leaving a small hole in the middle. I use 4043 rod because it seems to stick better to the metal that Suzuki jokingly refers to as aluminum. Be careful not to cover up that little side hole that you mentioned. That hole is necessary to properly drain the gearbox oil.

After the boss is built back up, repack the hole with grease and drill and tap the hole to the proper size. Then using a spot facer, reface the sealing surface for the washer. Check for pin holes using a little air pressure and some dish washing liquid and water.

Keep the heat low and your cases will be ok.

Just my $ .02

Ol'89r

 

[brandolph]

Thanks for the input.
I might be out of luck now because in my haste to ride the next day I flipped the bike over, cleaned everything up real nice and JBWelded the aluminum drainplug into the bike! Don't think it'll be too easy to get back out for a weld. Now I'm changing the oil through the oil level hole.