Pistons and Barrels

[Ggriffin236]

Hi everyone,

I have recently inherited a 1961 Ariel Arrow when my dad died. Unfortunately she is in a bit of a sorry state as the last tax disc 1973.

Anyway, i would like to ask for some advice to someone whose not worked on these bikes before. I have pulled the barrels off and removed the pistons with some effort. I have attached some photos below. Is is possible to just rehone these barrels as there isnt anything to catch a nail on, just surface rust and dirt? Or should I just get them bored. Measuring them, they are within spec. There is also a little section missing on the right intake of the right barrel, i believe its just a void in the casting but would this be an issue. Also, the pistons, are they salvageable. From my work on 4 strokes previously these would be manageable with some elbow grease but i understand tolerances are tighter for 2 strokes.

Thanks in advance.

[Ggriffin236]

Adding a comment with the rest of the photos.

[Roger Gwynn]

Difficult to tell from a photo but the cylinder appear to be badly rusted. The pistons do not look bad and if the rings can be freed off should be OK. First step would be to give all the bits a good clean!

[Mick D]

Hi

I think they look salvageable, start by cleaning the bores gently with wire wool and solvent/petrol, if they come back the rest should follow.
Don't be too critical of wear and finish, it's very easy, (and expensive), to go down the restore everything to as new rabbit hole.

Good luck Mick

[Bernie Blundell]

Fit old spark plugs into the heads, turn upside down, support to get heads level, fill combustion chamber with white spirit & leave to soften carbon deposits. Ditto pistons. When cleaning the barrel bore, work in a round & round motion, not an up & down motion which could leave an escape path for compression

[Ivor Collins]

I concur with the advice you’ve had to salvage without rebore and to reuse pistons.

You’ll probably have some piston slap noise when cold, don’t be alarmed by it, the sound reduces when warm and at least it won’t seize up as many newly rebored engines do. And, if at a later date you decide to go ‘the whole hog’ and do the rebore, it’s no big job to revisit.

The difficult job will be unsticking the piston rings. You’ll probably end up with some broken rings with which to scrape the ring grooves clear of corrosion before fitting the new ones

[Roger Gwynn]

Warming the pistons will make it easier to get the rings out, I once did it in a bus stop somewhere in Germany after she siezed.

[Mick D]

Hi

Those rings look like they have partially moved when they came out of the bores, if so, soaking in a good penetrating fluid, (I use ATF mixed 50:50 with acetone), whilst gently exercising the rings by compressing them with your fingers will get them moving. I wouldn't expect to break them.

Regards Mick