Well, Crud - the oil burning returns

[SteveFord]

Compression check:
140 - 190 - 180
added a little oil to cylinder #1 and it went up to 180.

Guess I found the problem. 
I knew I was in for it when I opened the air box and saw the filter was full of red sand dust from the original owner riding it off road in Florida. 

[SteveFord]

New valve guide seals, one "new" piston/liner, 3 sets of new rings and I'm back in business.
Quite the project but it sounds and runs much, much better than new.

[Lee337]

Out of curiosity, how easy is it to replace the liners?

I have a spare engine which probably needs all the liners replacing & I'm debating whether to rebuild it (as a project) or keep it for spares.

[SteveFord]

Having the motor out will make it a lot easier.  No intake parts, radiator or exhaust to deal with I trust.
It's remove the valve cover, align the timing marks (cylinder 1 TDC compression if I recall correctly), remove the timing chain tensioner, oil feed line, chain guide, remove the camshafts, remove the head and then you can fabricate a puller using three OATEY 33402 3" plumbing pipe test plugs, a threaded rod, two nuts and a stack of washers.
You just put the puller up on some pieces of board and they pop right out.  They're only held in with a bead of sealant.
Here's a nice write up and some pictures:
https://www.triumphrat.net/sprint-forum/945238-cracked-pistons-whats-the-path-forward-2.html

Smack the head bolts with a brass drift and a stout hammer to shock the suckers loose and just follow the manual step by step and to the letter.

I only replaced one piston and liner assembly with a used one from a breaker and ran a FlexHone through all 3 liners and then new rings and circlips.  Try as I might I could not find an aftermarket source for the Triumph rings which are stupidly expensive.

To replace the liners it's put some Hylomar on the stepped section where it mates the block and then you have to wiggle the liner over the rings, no ring compressor is used.  Weird set up but it works with enough patience.

[Lee337]

The top of the engine is already stripped down, so it's likely to be a long term project. From what you say, it's less daunting than I thought although sourcing replacement parts could be a challenge.

Thanks for the info & link, given me something to think about.

[SteveFord]

You're welcome.
Just take your time, go by the factory shop manual as the steps are really specific and mark everything with a Sharpie (magic marker) so it goes back in the same place it came out of. 
I like using cardboard egg containers for all of the parts in the cylinder head.