KH 500 Twin: cylinder overhauling and spares

[MartinL]

Hi All

The short story:
Is there currently any way of finding out whether there are any standard-sized cylinder liners and pistons for my KH 500 Hunter Twin in the Club's stock of spare parts and whether there is any chance of obtaining some in the next few weeks?
I know that the twin spares are currently in a handover from Rob Jameson to a new volunteer and that this process is not yet finalised.

The long story:
I am in the process of having the engine of my KH 500 Hunter Twin overhauled. My cylinder head has already been overhauled by a specialised company that Markus Nikot gave me the name of.
I then sent the cylinders, pistons and connecting rods to a renowned specialist company in southern Germany.

At +80, the pistons are oversized to an extent that is actually (no longer) available. Therefore, new piston rings that would be needed at least, are not available.
The idea so far has therefore been to have the pistons coated, the cylinders honed and new piston rings made. That adds up to a nice sum.
Probably, the better option would be to bring the cylinders to standard dimensions with cylinder liners and use new standard pistons. That would be part of the next overhaul anyway.
Unfortunately, Draganfly doesn't have the cylinder liners or the matching pistons on offer at the moment.

So I'm hoping that the club still has suitable spare parts in stock.

Martin

[dave.owen]

For pistons and liners go direct to IMD Cheshire
For any size rings use
Cox and Turner

Dave

[Julian Murphy]

For rings.

Always helpful.

https://www.coxandturner.co.uk/piston-rings/

[nevhunter]

Lot of Money Involved there. Perhaps try for a Better second hand Barrel that hasn't been bored out so much. I think 500 triumph twin pistons will fit with a slightly different pin bush.. Nev

[MartinL]

Thanks for all the hints.
On their website IMD does not list KH pistons. But I found some suitable at Ebay. But as long as I can`t get the liners it does not make sense to buy them now.
Maybe I have to wait, until liners and pistons are available at Draganfly (backorder status) or Spares for 4 Stroke engines are offered at AOMCC again.
Meanwhile, I also will keep my eyes open for a cylinder in good condition.

Martin

[david.anderson]

Martin
For cylinder liners try Westwood in the UK. They are very good to deal with. While they do not list a liner for the KH, try the Triumph speedtwin liner as it is the same bore as the KH. See this site
https://westwoodcylinderliners.co.uk/pr ... 249-498cc/
They will also make liners to your specification.
If however your bore is not shot and new rings will do the job then, as your bore is +.080 just use rings for a 75mm bore but quote the width of the rings and the radial depth. You will find that rings should be readily available.
David

[MartinL]

Update:
In response to my enquiry, Draganfly wrote that cylinder liners and pistons were available after all.
I have now ordered them and arranged with Motoren Graf near Freiburg to install the cylinder liners. They will also check the connecting rods for cracks.
Martin