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quallman1234
21st February 2008, 14:46
I put my new pistion in, turned it over slowly and the pistion skirts got stuck on the crank? and stopped it from turning over. I pulled the pistion out and managed to save it all! and it still turns over now.

Did i do something wrong? Or is the skirt length too long? :sweatdrop

Sully60
21st February 2008, 15:29
I put my new pistion in, turned it over slowly and the pistion skirts got stuck on the crank? and stopped it from turning over. I pulled the pistion out and managed to save it all! and it still turns over now.

Did i do something wrong? Or is the skirt length too long? :sweatdrop

If the skirts to long the chick's the legs are probably too hairy! :dodge:

Sounds like you've got the wrong piston son, better get a real good one i.e the proper one!

I would machine the skirt off if it was a 4T piston but I'd be checking that on a 2t. Ask F5Dave.

quallman1234
21st February 2008, 15:34
If the skirts to long the chick's the legs are probably too hairy! :dodge:

Sounds like you've got the wrong piston son, better get a real good one i.e the proper one!

I would machine the skirt off if it was a 4T piston but I'd be checking that on a 2t. Ask F5Dave.

Hmm very odd considering it has "AX100" on the side of the box and thats what i ordered. I could easily get it sliced off a bit on a lathe at work. Im going to measure my old pistion and compare.

Ocean1
21st February 2008, 15:36
Stab in the dark... Is there an arrow or a wee triangle on the crown?

boostin
21st February 2008, 15:38
Hmm very odd considering it has "AX100" on the side of the box and thats what i ordered. I could easily get it sliced off a bit on a lathe at work. Im going to measure my old pistion and compare.

That is the strangest thing, I am putting my CB125t together right now and found exactly the same thing, just put the piston in the vice and waiting on a grinder to free up. Of course I know that these are not original pistons so I have been expecting something like this.

boostin
21st February 2008, 15:39
Stab in the dark... Is there an arrow or a wee triangle on the crown?

I assume that points to the front, right?

Sully60
21st February 2008, 15:40
Stab in the dark... Is there an arrow or a wee triangle on the crown?

Yeah, worth checking dude, the two sides of the piston could have different lengths. That's not at all unusual in an oil burner.

Ocean1
21st February 2008, 15:40
I assume that points to the front, right?

Never seen one pointing backwards...

Sully60
21st February 2008, 15:42
That is the strangest thing, I am putting my CB125t together right now and found exactly the same thing, just put the piston in the vice and waiting on a grinder to free up. Of course I know that these are not original pistons so I have been expecting something like this.

Are you using C70 pistons?

Ocean1
21st February 2008, 15:42
Sure it's the skirt hitting the crank?

Not the ring hooking up on the bottom of a port?

boostin
21st February 2008, 15:44
Are you using C70 pistons?

Yes...did you just watch me stab that screw driver into my thumb installing the C clips?

quallman1234
21st February 2008, 15:44
They measure up the same? Im going to go ahead and pop my old pistion in (Not using circlips - gotta save em hehe) and see if the same thing happens!

quallman1234
21st February 2008, 15:47
Sure it's the skirt hitting the crank?

Not the ring hooking up on the bottom of a port?

Def the skirt hitting the crank. Can't be the ring hitting the bottom of the port because the cylinders not even on it when i try it.

Note - I measured the length of the skirt and also the height of the hole for the guogen.

Ocean1
21st February 2008, 15:48
Ah, no cyl. Got to be the wrong piston dude...

Sully60
21st February 2008, 15:48
Yes...did you just watch me stab that screw driver into my thumb installing the C clips?

Done three big bore CB125s now. My first was with C70 pistons.
Have you machined the barrell to get the comprssion back to where it should be(ish) You'll need to take .8mm off the barrel height.
I thought mine went quite well then I got the comp right and BoYaa! She was a flyer.
I have found some pistons that make for a much easier conversion too BTW.
We just reassembled Skunks twin and it was the best(easiest) one I've done yet.

Sully60
21st February 2008, 15:48
Changed the base gasket?

That wouldn't change the skirt to web clearance.

quallman1234
21st February 2008, 15:49
That is the strangest thing, I am putting my CB125t together right now and found exactly the same thing, just put the piston in the vice and waiting on a grinder to free up. Of course I know that these are not original pistons so I have been expecting something like this.

Yes the there is an arrow on top. I put the pistion in so its facing the exhaust port with this arrow.

quallman1234
21st February 2008, 15:51
Ah, no cyl. Got to be the wrong piston dude...

No no! lol, it fits fine in the cylinder. I took the cylinder off when it got siezed on the crank. i thought i broke a ring but it appeared that it was stuck on the crank and i couldn't turn it over. I took the pistion out and it turned over.

FROSTY
21st February 2008, 16:00
Humour an old(er) man. Grab the conrod with the crank at TDC -try to lift the bike with it.--Is there a clunk?

quallman1234
21st February 2008, 16:02
Well i figured it out.

Now taking guesses'

quallman1234
21st February 2008, 16:02
Humour an old(er) man. Grab the conrod with the crank at TDC -try to lift the bike with it.--Is there a clunk?

Big end still ok.

Ocean1
21st February 2008, 16:03
That wouldn't change the skirt to web clearance.

No, old memory of a base gasket fouling a piston many years ago.


No no! lol, it fits fine in the cylinder. I took the cylinder off when it got siezed on the crank. i thought i broke a ring but it appeared that it was stuck on the crank and i couldn't turn it over. I took the pistion out and it turned over.

Dunno dude, got me fookt.

How much side-play is there in the piston on the gudgeon? Does it help if you centralise it?

quallman1234
21st February 2008, 16:04
Well ill give it a way. It appears that on a AX100, The arrow on the crown should face backwards?

Ocean1
21st February 2008, 16:06
Well ill give it a way. It appears that on a AX100, The arrow on the crown should face backwards?

Well I'll be fookt...

quallman1234
21st February 2008, 16:07
Sorry nevermind i take that back gahhh. Im doing this as well speak. Ill try my old pistion now. Sorry ocean. Ill try it with the cylinder on as well maybe its just me holding it at a funny angle whilst turning it over.

Sully60
21st February 2008, 16:08
Well ill give it a way. It appears that on a AX100, The arrow on the crown should face backwards?
That would have had me too!
An "in" would have been helpful!

Do the piston ports look a bit closer to where they should be now?

Ocean1
21st February 2008, 16:12
Sorry nevermind i take that back gahhh. Im doing this as well speak. Ill try my old pistion now. Sorry ocean. Ill try it with the cylinder on as well maybe its just me holding it at a funny angle whilst turning it over.

:laugh: Gota hold yer tongue right mate.

quallman1234
21st February 2008, 16:18
There appears to be a small piece of metal on the crank, right at the point where i think the pistion is hitting the crank. Shouldn't be any damage to the crank it self, because i only have lightly turned it over since my old pistion fucked it self. Yea too right i need to relax and not rush things.

Str8 Jacket
21st February 2008, 16:20
Ah fuck dude! You're having a worse time than me..... Bet your not throwing a tanty though eh?! ;)

quallman1234
21st February 2008, 16:20
Ah fuck dude! You're having a worse time than me..... Bet your not throwing a tanty though eh?! ;)

Completely relaxed

Str8 Jacket
21st February 2008, 16:26
Completely relaxed

Sweet. Good luck!! I'd tell you that mine will hopefully be sorted tonight but that would just be mean! :D

quallman1234
21st February 2008, 19:47
Was only hitting the crank by the tinest amount, a quick but gentle use of a file and it was going up and down lots with plently of clearance. Only problem was in the mean time i need new circlips.

Anyone know of someone who might stock em. I think its a 14mm Gugenon pin slot. - Nevermind i got some sorted.

Ocean1
21st February 2008, 19:59
Try SAECO on the Hutt rd, or SKF down Seaview.

Check the thickness too.