jaybar6
XS650 Addict
I don't have a lathe or a milling machine, so i thought I would buy some oversize pistons and file the cylinder out until the piston slides in smoothly. Maybe a grinding head would be quicker with a drill. any thoughts?
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can you do a re-bore with a file?
- Thread starter jaybar6
- Start date
I don't think that could be done in a million years but I met a man many years ago, worked in India repairing army lorries at the end of WW2 told me how they did a rebore without the proper equipment.
They cut the old piston down the middle, put the block on the ground, replaced the piston into the bore with a wooden wedge to force it against the sides and a long piece of wood as a handle, utilised river mud as grinding paste and punkah-wallahed the piston up and down the bore, patiently rotating and measuring until they had removed enough metal for the new oversize piston to fit.
Equipment and parts were expensive, labour was cheap.
They cut the old piston down the middle, put the block on the ground, replaced the piston into the bore with a wooden wedge to force it against the sides and a long piece of wood as a handle, utilised river mud as grinding paste and punkah-wallahed the piston up and down the bore, patiently rotating and measuring until they had removed enough metal for the new oversize piston to fit.
Equipment and parts were expensive, labour was cheap.
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What could possibly go wrong with that plan?
bazz
XS650 Enthusiast
Get it done by an expert - Rebores in the UK are not very expensive. Then you will need to check the ring gaps, this can be done with a feeler gauge and a "File". The direction of filing is important so you do not chip off the chrome coating the rings might have.
I used Cardiff Pistons for my rebore about 7 Years ago and it cost £150 for both cylinders. I would guess the price now would be about £300. Shop around and look for engine machine shops that specialize in reboring. Bike shops will do it but generally via a 3rd Party so you will pay a commission.
I used Cardiff Pistons for my rebore about 7 Years ago and it cost £150 for both cylinders. I would guess the price now would be about £300. Shop around and look for engine machine shops that specialize in reboring. Bike shops will do it but generally via a 3rd Party so you will pay a commission.
Max Midnight
XS650 Addict
Perhaps the Mancunian dampness has affected his thinking?
But to answer th question, yes, of course you can but you will need to acquire a special sort of file to do the job.
It looks like this....
jaybar6
XS650 Addict
Yes Raymond, that is the answer! I can use the old piston to do the same job. Brilliant!
jaybar6
XS650 Addict
That is £300 including the pistons?
jaybar6
XS650 Addict
If alan millyard can use a file, a junior hacksaw and a ball of string... so can I.
jaybar6
XS650 Addict
I could weld a rod on to the old piston and stick it in a drill. using the valve grinding paste hone out the bore till the over sized pistons slide in. 
for $100 US + postage, 533 pistons can b got from here. 447 pistons for $80 US. Quality is good. They are the go to pistons for the XS650 unless your looking for high compression pistons
https://www.cruzinimage.net/category/item/itemgenre/motorcycle/yamaha/pistons-yamaha/
https://www.cruzinimage.net/category/item/itemgenre/motorcycle/yamaha/pistons-yamaha/
Not saying you can't do it............ Precision welding and rod placement or your going to wobble.I could weld a rod on to the old piston and stick it in a drill. using the valve grinding paste hone out the bore till the over sized pistons slide in.
This is one of them conversations usually held in the pub. The more beer consumed, the more seems possible . . .
jaybar6
XS650 Addict
thanks for that skull.
jaybar6
XS650 Addict
after a pint i can do anything.
£300 and you supply them the pistons and cylinders. The bores are made slightly oversize in accordance with the piston/cylinder clearance. I have checked Ebay UK and you can buy Indian Clay which could be watered down to form Indian mud:
Indian Clay
Indian Clay
jaybar6
XS650 Addict
jaybar6
XS650 Addict
Thank you for the information, Paul. would Manchester canal mud be ok?
As Skull has mentioned above, many of us have used the pistons from "cruzinimage" and the pricing is very good. When I ordered mine they arrived from Japan within 1 week. Cardiff Pistons measured the pistons and found them to be identical - that's modern machining for ya.
Do you really need a rebore? Perhaps a gentle hone prior to inserting the old pistons with new rings is enough. A machine shop could quickly measure the cylinders and old pistons and give you a good opinion on whether new rings are sufficient.
