I killed Elsie

[dangerous]

I can see detonation damage. The "ball bearings" are the result of gasified aluminium being attracted to the spark plug. You can see the seizure marks on the pistons too

I am tending to disagree... the seizure damage you mention is on most if not all RD pistons, 4 corners seize or cold seize common and often never felt.
Same with detonation marks... you will and often should find detonation damage on the tops of well tuned 2 stroke engines.

[gijoe1313]

Ah poos and wees and naughty words! Sorry to hear and see such a sight!

I think this is one of those times where I didn't want to see the piccies!

Do keep us informed of any progress on the rebuild? Replacement?

[Kickaha]

I haven't rebuilt a bottom end before but I'm guessing it'll cost a fair bit to do Any ideas?

Do it once, do it right, you wont have to do it again, do you want to take the chance of a secondhand crank doing the same thing?

http://www.pjme.co.uk/acatalog/Onlin...250LC__60.html
http://www.yambits.co.uk/catalog/ind...4b212c3931543e

Anyone know how different a TZR bottom end is? I have one sitting around.

Different enough that they won't fit and depending on who you talk to neither will the banshee crank with out modification
http://www.wiseco.com/PDFs/Wiseco-Ya...rankshafts.pdf

[ajturbo]

http://stores.ebay.co.uk/Janets-Bike...QQfsubZ0QQtZkm

try this big boy

[geoffm]

LC rods have 1mm narrow bigends than RZ/YPVS/banshee crahnks. I know people have used RZ cranks but surgery is involved. The RZ parts are usable for LC cranks IIRC, except the crankpins are 1mm longer and need shortening.
Geoff

[Skunk]

I'm amazed it wasn't making a horrific racket before it died.

I was having a miss fire problem for a few weeks before she died but other than that no noises that she hasn't made for the last year or more.

Caused usually by incorrect ignition timing (less likely nowdays with electronic ignition). Or a lean mixture (air leaks on the engine side of the carb is a sneaky cause. Or even sneakier is switching from autolube to petroil); or maybe a wrong spark plug (especially if this is a racer).

None apply in this case.

I think the bits in the transfer ports are remains of the bearing cages.

Correct

Only thing you will need, is a flywheel puller. You can't improvise it.

Got one.

na, damage is all caused from debris from the bottom end.
yip... thats a bloody good job done Skunk, the ball bearings stuck in the spark pulg is a nice touch too.
So for some reason the botom end gave up the ghost and in turn screwed the rest You running the pump or pre mix?) well the cranks are in 3 parts I think 350 and 250's are the same. Good luck and hows bout a pic of the entire bike

Correct about the damage from the bottom end.

Skunk...Looks fucked...give it to me if you don't want it

Take a long week off the shortest pier...

poor baby... you aint getting ya mitts on MY Elsie anytime soon
but ya gotta get her back alive again, you just GOTTA!

Damn right! I'm going to get the frame powder coated while she apart.

I can see detonation damage. The "ball bearings" are the result of gasified aluminium being attracted to the spark plug. You can see the seizure marks on the pistons too. But some of the damage is "battering" from lower end debris being flung around.

The cranks are in 5 parts (plus seals). An outer web at each end, an inner web for each cyclinder with the crankpin integral, and a central shaft . All parts are obtainable. As are rods and big ends. Cost a few $$$ though, hence might be cheaper to source a second hand crank or complete engine.

Ah two strokes. It's what they do. Is why we luvs them so

Thanks for the info.

Do it once, do it right, you wont have to do it again, do you want to take the chance of a secondhand crank doing the same thing?
http://www.pjme.co.uk/acatalog/Onlin...250LC__60.html
http://www.yambits.co.uk/catalog/ind...4b212c3931543e
Different enough that they won't fit and depending on who you talk to neither will the banshee crank with out modification
http://www.wiseco.com/PDFs/Wiseco-Ya...rankshafts.pdf

LC rods have 1mm narrow bigends than RZ/YPVS/banshee crahnks. I know people have used RZ cranks but surgery is involved. The RZ parts are usable for LC cranks IIRC, except the crankpins are 1mm longer and need shortening.
Geoff

I have a complete TZR bottom end; rods included. I just haven't measured anything as I can't actually find it at the moment...

Thanks for the links I'll start checking it all out. Give me a shout if you find a crank eh?

[Ixion]

There is enormous confusion about this. I believe that the difference is between the YPVS models and the earlier non-YPVS. In NZ , the YPVS was called the RZ , and the non-YPVS the RD-LC. But in other countries the YPVS was also called the RD-LC. I'm not sure which Mr Skunk has

If it is YPVS I think the Banshee crank either fits or can relatively easily be made to do so. To use a YPVS crank in a non YPVS the crankcases need machining. To use a non YPVS crank in a YPVS the crankcases need stuffing (but it is not recommended anyway)

I think that the big end parts for the RD cranks will fit the LC (and RZ too , maybe). But the crank end is different because of the water pump and electronic ignition.

But, regardless, new parts are available for all models. So it is not necessary to munge unless one has a crank sitting around that one wants to use.

[Skunk]

I have the 82 RD250LC, not the RZ YPVS. I'm pretty sure that the parts won't fit but was hoping someone would confirm otherwise. I was thinking along the lines of using the conrods to sprocket off the TZR and the head, barrels and pistons off the RD until I can rebuild the RD properly.

[Skunk]

Parts from Yambits will cost around $645 plus freight from the UK. Not too bad - if I had that sort of money...

Start saving... I'm still going to BoBTT though.

[Grub]

I have seen Elsie's innards tonight - it was not a pretty sight, I've had to come home, taken two panadol and had a lie down.

[F5 Dave]

Sorry to hear, could be several reasons for this. Perhaps a twisted crank has altered the timing on that side, or a shifted flywheel & one side was closer to the edge than the other. Or a leaking crank seal on that side. My RZ killed that side as the oil pump drive seal was leaking & starving oil to cylinder, alternatively the carb injection could be blocked, minor seizure twists crank etc.

All things to think about but all should be addressed by rebuild. Can borrow my leakdown tester when all back together. Reedblocks etc can leak. If we can bung up the carb hole with some rod & a plate over the exhaust port then the spark plug fitting of the tester will work.

Pity the LC & YPVS cranks are different as I have a low mileage YPVS one after putting a stroked Banshee billet crank in my new RZ.

[Kickaha]

Pity the LC & YPVS cranks are different as I have a low mileage YPVS one after putting a stroked Banshee billet crank in my new RZ.

They will fit with a bit of modification, if I remember rightly the cranks are slightly wider, so you either have to machine the cases or machine the crank webs so it will slot in

[mitchilin]

This is not going to help,but I thought these things were "unkillable".Had one for 18 months and tried.Had some issues with the waterpump(put water in it)but hell,what a reliable bike.Great to see some people keeping them going.Air cooled bikes I spent hundreds on before "learning"

[Skunk]

I've removed the crank now and there's more damage than it first looked. One of the main bearings is only half there. It run smoothly though. Odd.

I freed up the big that was jammed. It's missing half the needles and the cage is gone. Now I need to press it apart. Best quote so far is $160.

[skidMark]

The R in the plug name means resistor. cant use resistored plugs on 2 strokes.