I killed Elsie

[Skunk]

I did it. It was me.

I'm not too sure what I've done yet but I shall discover.

She's had a miss-fire ever since I changed a dead plug. I didn't have a B8ES so I used a spare BR8ES. Worked fine for a week or so then came the miss. Swapped the plug to the other cylinder and the miss moved as well.

Swapped that plug for a new BR8ES and the miss came back half a k down the road.

Asked around and got told that she has a separate generating circuit for the coils (as I checked the battery charging circuit and it's mint) and that this may be dying. Purchased a new B8ES and she ran sweet all the way to work and 98% of the journey home.

Big spit out the exhaust, a miss, one on one then stop.

Can't turn it over.

Ah well, another engine to strip down. I have spare barrels and odds and ends but I'm hoping it's not that bad.

Oh, and the side stand bolt snapped at some stage the same day. Went to put it on the side stand and the head and shank of the bolt fell out.

I love old bikes. Really I do.

[Trudes]

Ahhh, crapola!!!!
I'll help you if you like (doing what I don't know, handing you tools, handing you drinks, mopping your brow, acting as a centre stand.....)

[Mom]

Ahhh, crapola!!!!
I'll help you if you like (doing what I don't know, handing you tools, handing you drinks, mopping your brow, acting as a centre stand.....)

You forgot the most important bit mate.....looking pretty!

[surfchick]

.... acting as a centre stand.....)

a gift indeed!!

[Trudes]

You forgot the most important bit mate.....looking pretty!

Ummm, have you seen Skunk's bucket factory?? And for some reason everytime I leave there I'm caked in grease, petrol, oil and shit!! Not a lot of room for looking (or smelling) too pretty there!! I'll leave the looking pretty to Skunk Control, she does it better than me (and makes a mean coffee!!)

[Skunk]

After being told to get off my arse and strip it down I have.

I didn't just kill her - I butchered her. She's fucked.

It won't turn over because the right side big end is seized.
The left side big end is toast (1.5mm free play side to side).
Both pistons are buggered.
Barrels look OK to me but I'll get them checked.

Some I need to pull the crank apart...

Two things:
What things could I have done wrong to do this? Don't want to kill another...
I haven't rebuilt a bottom end before but I'm guessing it'll cost a fair bit to do Any ideas?

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

Those aren't the rings sitting in the transfers; the rings are complete. I guessing they are the big end bearing.

[The Pastor]

dude. thats just not cool.

[xwhatsit]

What are those ball-bearing looking things up around the spark plug?

[CookMySock]

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

DB

[martybabe]

What are those ball-bearing looking things up around the spark plug?

Looks like melted piston to me. either way I think an, oh bugger, is called for.

Hard luck mate .

[Ixion]

Bugger. And double bugger.

Pre ignition and detonation.

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) .

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

Fortunately the bottom end strip is no big deal. Heads and barrels off, engine out of frame, remove flywheel, remove clutch and associated clobber, lots of bolts on the bottom case and it all lifts off. Only thing you will need, is a flywheel puller. You can't improvise it.

(EDIT: TZR crank won't fit without much munging. You can get all the bits to rebuild the crank but you need a 20 ton press and quite a bit of skill. Maybe a secondhand crankshaft ? . You can also get aftermarket cranks (ex USA) for the Banshee trike, which fit (there may be an issue with the oil pump drive- not certain but its not hard to fix). The Banshee is 350cc but the 250 and 350 cranks are the same (not absolutely technically correct because of balance - the pistons are different weights, but close enough for the real worls )

[dangerous]

Looks like melted piston to me.

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

[Slingshot]

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

[Rashika]

poor baby...
you aint getting ya mitts on MY Elsie anytime soon

but ya gotta get her back alive again, you just GOTTA!

[Ixion]

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

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