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British Bikes / Re: BSA L29
« Last post by cardan on August 19, 2019, 11:52:30 PM »

Alloy I think, judging by the look of the corrosion. I use a stone lubricated with kerosene (paraffin I think you call it) on cast iron pistons, but only ever a new file on an alloy piston. A used file often has shards of steel that can end up embedded in the soft piston.

R gives excellent advice. Can I add a warning? There is a mistake that many of us have made once - once is enough - that should be avoided at all costs.

With a one-piece cylinder and head be extremely careful if you put the loose piston and rings inside the cylinder. Do not push the piston up to the top! If the rings go over the top of the bore they will pop out into the combustion chamber, and getting the whole thing out again is extremely difficult. It's one of those "oh no" moments.

Have fun.

Leon
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British Bikes / Re: BSA L29
« Last post by R on August 19, 2019, 11:34:32 PM »
P.S. I should have first asked if that piston is iron or alloy ? It looks iron ?
Iron can withstand stronger treatment, including fine filing.
And is less prone to emery particles embedding in the surface.
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British Bikes / Re: BSA L29
« Last post by R on August 19, 2019, 11:00:07 PM »
Yes you have to be cautious using emery cloth ANYWHERE inside an engine or on components,
the particles can remain, and turn into grinding paste !

The corrosion on the side of the piston if machined off would cause the piston
to have more clearance and thus piston slap - but won't affect compression.
I use a well blunted stainless steel wool - give all your saucepans a good clean with it first,
to blunt all the sharp edges. Polish in small circles, so you don't wear grooves in any particular direction.
Watch that it doesn't produce any visible scratches, in which case its not blunt enough.

The carbon on the top of the piston can mostly be scraped off using a blunt instrument - I mostly use a
sharpened wooden stick !  The aforementioned stainless steel wool also works well here.
Again watch that there are no scratches -  the piston top is not really a working surface,
although the finish is often less than pristine from previous owners attempts !
Smoothing off any previous scratches is a good plan, you don't want lumps or bumps becoming hot spots,
and possibly causing pre-ignition.


And the reason I mention STAINLESS steel wool is that ordinary stuff leaves tiny bits of steel wool everywhere,
which soon rust if exposed to dampness anytime - the last thing you want inside engines. (or outside for that matter).
Stainless wool  mostly breaks into long strands, which are easy to spot - and obviously kept away from inside engines.
have fun !
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British Bikes / Re: BSA L29
« Last post by robbsa on August 19, 2019, 09:39:06 PM »
Good news, I have obtained a split washer, connected up the spark plug and attached the magneto to my drill......and have a spark!

Thanks for the help.

I've built myself a jig to help me work on the engine whilst I work on the frame. and the next step is to get the piston and cylinder head back on. The bore looks okay in the cylinder but since been left in the garage, the piston has got a bit of surface corrosion and also has some carbon build up.

The surface corrosion looks like it could be taken off with a bit of emery paper, but I'm guessing this will possibly ruin my compression?should this be machined? not sure how to get the carbon crust off without damaging the piston. Any further top tips?!

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Japanese Bikes / Re: The rarest Honda in the world for sale! Dream MF350 from 1956
« Last post by terecha on August 19, 2019, 11:29:35 AM »
Hi

I had couple of interested persons from Saudi Arabia, India and South Africa, but decided not to ship to those destinations. Mentioned countries are unstable and bike could be stolen during transport.
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Japanese Bikes / Re: The rarest Honda in the world for sale! Dream MF350 from 1956
« Last post by iansoady on August 19, 2019, 11:18:40 AM »
I seem to remember you were trying to flog another very rare Honda last year for a huge price. How did that go?
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Japanese Bikes / Re: The rarest Honda in the world for sale! Dream MF350 from 1956
« Last post by terecha on August 18, 2019, 10:49:41 AM »
Have this adjuster, but forgotten to install :D

Will ask Honda Museum, thank you for the advice.
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Japanese Bikes / Re: The rarest Honda in the world for sale! Dream MF350 from 1957
« Last post by Rex on August 18, 2019, 09:12:10 AM »
A lot of work's gone into that, but the wiring under the headlight could do with tidying up, and the clutch cable adjuster lock nut is missing... ;)

Aren't Honda interested in buying it for their museum?
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Japanese Bikes / Re: Thassos island Greece with Yamaha Tenere xt660z
« Last post by R on August 18, 2019, 05:32:33 AM »
Nice resort doco, thanks !
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Japanese Bikes / Re: The rarest Honda in the world for sale! Dream MF350 from 1957
« Last post by R on August 18, 2019, 05:31:28 AM »
I hate to say this, but that would have been a spectacular bike if it had been merely repaired and kept in its original condition.
Original bikes are rare survivors -  I love original bikes...

Good luck with the sale, thanks for showing.

https://obrazki.elektroda.pl/1467556800_1566063104.jpg
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