Derestricting my TZR 250 3XV RS

[AndyYam]

Plus Gas is the English equivalent, it's very good.

50/50 acetone and ATF is the ghetto equivalent, it's very dangerous.

+1 for plusgas, thats what I've always used. I just bought some little needle tip applicator bottles to use mine with as the plastic screw top bit has torn and I've been wasting loads pouring it everywhere whilst trying to pin point a bolt/thread.

Freeze and release sprays can also help in conjuction with heat if used carefully. It can just get it to exapnd and contract enough to break that corrosion seal.

https://www.eurocarparts.com/p/normfest-super-crack-ultra-ice-rust-remover-400ml-NOR28944421?type=shopping&gclid=Cj0KCQjwwY-LBhD6ARIsACvT72PmeQ0Hvj8PGOh3Z5ZIHtcOTArZTXUQiYFOXtJ_EIN4lr6xgOR5F-MaAsmREALw_wcB

[SouthCoastRich]

Thanks Andy. That freeze spray looks really interesting too! I now have the right tool for the job that came in the post today via Royal Snail  (see pics) and will give this a go tomorrow... with care and a lot more knowledge from the advice of all here!

[SeaR1ck]

Oh your trying to split the case. I would have dropped the engine from the frame. It's a whole lot easier that way. The engine isn't that heavy like 75 pounds.

[SouthCoastRich]

Oh your trying to split the case. I would have dropped the engine from the frame. It's a whole lot easier that way. The engine isn't that heavy like 75 pounds.

Yes, I'm being guilty of not following the advice of the more experienced  I thought I'd drop it if I got stuck, but so far (15 bolts to go) I haven't. I suspect I still have a chance to regret that decision and had the rear cylinder head not come off the barrel that would have been one point I'd have bit the bullet.

[Warwick]

You can replace the crank/rebuild top ends easily enough with the motor in situ, but removing the motor first means it's easier to clean things up properly before starting. And when rebuilding you can get at everything more easily and you can ensure no debris drops into the motor while working more easily etc. If there's the time available, I would always drop it out myself.

Given that you've split it uncleaned and in situ though, you'll just need to take a little extra care to avoid dirt and debris ingress when rebuilding it.

[SouthCoastRich]

Given that you've split it uncleaned and in situ though, you'll just need to take a little extra care to avoid dirt and debris ingress when rebuilding it.

Yes, that's a critical thought 

[SouthCoastRich]

The correct length and selection of 5 & 6mm hex bits, a selection of extension bars and all is good. The last 15 of these crusty critters are out. In fact only a few on the left hand side (upper) were this bad. Now I have a split crankcase with a crank in it.

The 6mm hex bolts either side of the conrods were nice and easy to get out thanks to a helpful engineer 30 years ago making cut out for a snug socket 

[SouthCoastRich]

So (apart from trying to get the crank out of the case) that's all the disassembly done.

Onto cleaning and inspection.

Looking at the right side (lower) it's possible it wasn't the gearbox side oil seal as much as it was the bearing... looks a little odd in there and the other side is spotless.

[SouthCoastRich]

(full pic for context)

[SouthCoastRich]

The gearbox side crank seal that came out looks good but I guess there's no way to really tell. The crank bearings run ok, but I'm no engineer. Centre one seems a little rough though, but hard to say with the centre seal. Big ends don't appear to have any longitudinal movement, just a little side to side, and the bearings there look good too.

So no obvious signs how gearbox oil was getting into the right pot. Judging by the black sealant around the crankcase faces at weak points only (like the bolt holes) and not all over the faces, I'd say this hasn't been apart.

However - The right side crankcase has definitely had a gut punch. No materials in there so it may be an old ring nibble from long long ago, but there's definite scuffing on the conrod and what looks like torn material on the crankcase where it runs.

What's the recommended way to fix this? Or should I just leave it?

[Steveog]

Hi Rich.

As you may know, I've had three major nip-ups that gouged out both sides of my 3xv crankcase. I was advised by the gurus here in 2018 to sand/down the high spots (top of photo), but, later a wrist pin did far more damage and caused the lower crater (highlighted by arrow).

I decided to "FILL" all the gouges as best as I could. The lower one took using a Dremel with a 45 degree attachment to even out the raised areas of aluminum. After that, sandpaper and Heavy ScotchBrite cleaned it all up. Then all thoroughly cleaned with Acetone and stiff brushes. Dried with compressed air then applied JB Epoxy before any dust had a chance to collect. It takes a full 24 hours to cure. It was then sanded and contoured back to its original shape and sealing properties. This case has since been opened and checked with no sign of the filler breaking loose.

Hope this helps if you decide to work on the divot.

Good Luck.

Steve

[SouthCoastRich]

As you may know, I've had three major nip-ups that gouged out both sides of my 3xv crankcase.

Yes, I know! I've been looking through the wrist pin and project pheonix threads saying to myself - well it looks better than that so I should be ok!

Credits to AndyYam who suggested putting some oil in and see if it went away - so a bit of blu tac engineering and tested that. The oil did disappear

So I whipped out the gear box and bad news - it's been punched through.

[SeaR1ck]

Oh that sucks some engine cases on yahoo right now. I know it could be repaired but it won't be cheap. I would rather get a set of cases myself.

[SouthCoastRich]

Oh that sucks some engine cases on yahoo right now. I know it could be repaired but it won't be cheap. I would rather get a set of cases myself.

There's one on eBay, I've emailed the seller to get more info. 

I guess (trying to look on the positive) I have the option of sealing the leak on the gearbox or crank side... 

[yanw]

I think maybe take it to an engineering shop and get them to drill it to get some nice oil free metal,  then TIG the hole up. I suspect it would be cheaper than new cases and IIRC you should get matched pairs.