2007 Honda CR85RB Build

[Paul_E_D]

Zero traction and no rear brakes! Felt pretty good though, just wanted to get it through the gears and on the pipe to break it in some.



Well, no. I popped a bearing, installed the new center axle tube & spacers, then added a washer again to get enough clearance. So basically back where I started.

Ah, just run it. Ain't nobody got time for that!

[Tekime]

Well Dubya replied a few moments after that post and they're sending out a new RM/YZ spacer to try out (presumably at no charge). All else fails the setup is fine, just needs an extra washer in there.

[Tekime]

A bit puzzled here. There's a tiny hole on the right crankcase cover, below the water pump, and it's weeping oil. Pretty sure it's just clean trans oil.

The service manual and the parts fiche make no mention of this hole.

Google search reveals a lot of people saying it's in a void space, and/or that it's a coolant weep hole to keep a leaking pump gasket from dumping into the case.

Far as I can see, this section of the crankcase is *not* a void space or separated from the transmission. The water pump essentially sits on the outside of the right case cover.

Searching eBay/Google images, I see a few case with a screw or plug in this hole - but I don't see any threads.

Random eBay pic, the hole is on the bottom right of the crankcase in this pic:



On this pic (eBay auction) there is a threaded bolt in that hole:



In this crappy image, it looks like a closed section leading to the pump bearing:



Any thoughts? This is basically right where the main water pump shaft sits and presumably is lubricated by trans oil.

My only conclusion is that this is supposed to be plugged?

[Kurlon]

That's a tell tale weep hole. It's telling you the oil side seal on the waterpump is failing. The hole is plumbed to where the bearing sits, what comes out tells you which seal is letting go, oil side or water side.

Honda PN 91201-035-015 IIRC

[Tekime]

You are the man! That makes a lot of sense. I was just poring over photos of the build and found a nice closeup of the plumped hole and that is exactly the case. So looks like there are two seals mated there, and either I bunged it up or completely left it out.

Judging by the fiche, I *think* I can check it via the pump cover.

[number9]

That's a tell tale weep hole. It's telling you the oil side seal on the waterpump is failing. The hole is plumbed to where the bearing sits, what comes out tells you which seal is letting go, oil side or water side.

Honda PN 91201-035-015 IIRC

You should have your own sub-forum on NESR tbh

[Tekime]

Kurlon's Korner

[tls25rs]

Kind of a cool design feature.

If your oil seal on the water pump goes you see oil out the weep hole, if the water seal on the water pump goes you see water out the weep hole. Keeps water from getting in the oil or oil from getting in the water.

My YZ has eaten a few water pump seals over the years, all on the water side due to corrosion but still cool to see how the engineers solve issues like driving the water pump from the crankcase side of things without the possibility of cross contamination for anything less than a catastrophic failure. Or, as can be seen in the photo with the bolt in the weep hole, a better idiot comes along and completely defeats that engineering that went into the design.

[number9]

Kurlon's Korner

Winner winner chicken dinner

[Tekime]

Really cool engineering indeed. When I first saw it dripping I thought damn, a gasket already? Did I overfill it? I noted it during assembly but never saw anything in the Honda books about it. Then after looking at eBay trash it really had me confused. Tracked it back to the bearing, but obviously there are no galleys as there's no oil being pumped.. what in the &#@?

Two seals. Goddamn beautiful.

[Tekime]

Fixed. I had left the oil seal out, and to add insult to injury the service manual very clearly covers the installation of both seals. Live and learn.

[Paul_E_D]

I think all of my 2 strokes have had this design?

[MHenry600]

So, I happen to have a mini lathe, and a small mix of hss and carbide insert tools. I'm not the best machinist (I'm an engineer who sits at a desk all day), but could try to take a wack at it on the side.

I just went back, but couldn't find your sketch of the spacers in the posts anymore, unless I'm just missing it.

I could either look to make aluminum, or could try some steel ones. I need to check at work, but I might be able to find some small scraps of nice 15-5 or 17-4 cres.

If you give me the dimensions/sketch I can take a peek if you want. Not looking to make much money, but would need to at least cover materials costs. If I can find some scrap drops at work, should be cheap.

[Tekime]

Probably a common design - my first two stroke build so new to me.

Snow melted a tiny bit here so I took it out yesterday, noticed it rapidly losing power to the point it was just bogging out under any kind of load and only revving to like 80%. Still started and idled no problem. Bit of a panic, checking the coil ground, fuel flow, carb settings, etc. but no luck. It reminded me of the time I left my exhaust plug on my KTM... checked the exhaust and almost no flow at all.

Turns out there was a giant petrified nest in the expansion chamber. Must have been fused to the chamber and come loose, completely clogging up the pipe. Spent a wonderful hour with some Purple Power, kerosene, mineral spirits, and an extended grabber claw pulling the most vile, heinous wads of carbon scorched slop out bit by bit. Hay, acorns, hair, dirt, fishing line, cloth, and to top it off an entire mouse.

Bike feels frigging amazing now.

[Tekime]

So, I happen to have a mini lathe, and a small mix of hss and carbide insert tools. I'm not the best machinist (I'm an engineer who sits at a desk all day), but could try to take a wack at it on the side.

I just went back, but couldn't find your sketch of the spacers in the posts anymore, unless I'm just missing it.

I could either look to make aluminum, or could try some steel ones. I need to check at work, but I might be able to find some small scraps of nice 15-5 or 17-4 cres.

If you give me the dimensions/sketch I can take a peek if you want. Not looking to make much money, but would need to at least cover materials costs. If I can find some scrap drops at work, should be cheap.

Thanks for the offer man! Dubya is sending out a new left spacer so I should know if that works by next week. Will definitely keep this in mind.

[Paul_E_D]

To clean a chamber, spray in oven cleaner, drop in a handful of nuts and bolts (not acorns) and shake vigorously. As it says on your shampoo bottle, rinse and repeat.

[Tekime]

New RM spacers came in. Can't explain why, but I swapped both sides and they fit perfectly.

[Tekime]

Rear brake master rebuild:





Hour meter installed few days ago and put the OTC to work:

[joshk1025]

Rear brake master rebuild:





Hour meter installed few days ago and put the OTC to work:

What did you do to get that so shiny?

[Tekime]

Brass brush + wire wheel.

[typeone]

dammit, i need to work on my carcass ! excellent stuffs :erectthumb:

[Paul_E_D]

Get that thing out on some ice tires!

[Paul_E_D]

It would absolutely slay it out there.

Sent from my SM-G930V using Tapatalk

[Tekime]

Read my mind. My brother and I are scheming for a day of ice fishing in the midcoast and I'm dying to take the CR out. Especially since I don't fish. Need to find some screws and decide if I'm going to go for another set of tires...