Hi,
Interesting memories Bogs, I don’t recall problems with the carb on the 60 but then it wasn’t raced, well that is, pushed to the limit, and it was always hand started with a cord!! I think I also ran it on straight mix i.e. no nitro which if memory serves correct was how the OPS of the time was set up. Ah! too long ago to think about eh?
That ‘thin’ pipe I do remember and seeing it disappear – for the second time – (didn’t learn much there the first time) was a gut wrencher. The first was very close to the bank and was retrieved but no such luck the next time. One thing’s for sure they will be held much more secure this time round!!
Well despite it’s appearance and condition and after a few anxious, ‘nipped up’ moments I’m pleased to say that the engine is now stripped to it’s major parts.
Three of the head bolts lived up to expectation, the first undoing with that ‘crack’ of a well torqued caphead. The force required on the others was immense but the normal worry that the socket would open or the key would ring was not founded. It was only after I picked up the hex key to take off the front housing that I noticed the inbuilt corkscrew!!
(Sorry just couldn't resist these!!)
With the head off, the next concern - the flywheel – proved unfounded. It fell off with a single tap with a plastic faced hammer. The real sting in the tail though was the liner - an absolute sod but lots of heat, some ice cold water poured in the liner at the moment of truth courtesy of SWMBO and out she popped unscathed.
The piston was extremely tight in the top half of the liner (
interference fit 10mm from the top!!) and it turns out this was due to a virtually invisible ‘salt(?)induced glaze’, the bottom half of the piston some 2 thou bigger than the top half. Thoughts of how to true the piston diminished after dunking the piston in cellulose thinner revealed the glass hard glaze as a white deposit. A very careful scraping with a scalpel showed the deposit had broken down in the thinners and it just flaked off. A very light touch with a piece of 1200 wet and dry with lots of lube and the piston dropped back in the liner running smooth and just nipping at the top as it should. So far so good.
The main bearing had totally seized and the crankshaft shows sign of running in the bearing. The bearings were much easier to remove than expected and some replacements are on order at a local supplier.
Since this pic the gudgeon pin has been removed as the con-rod needs rebushing at the bottom end, the little end showing no sign of wear.
Does anyone know of a source of the circular wire retaining clips that retain the pin or are these specific to OPS engines.?
Well that’s it, stage one over much more quickly than anticipated. The rebuild will be much more sedate as I would like to bring it back to as new a looking condition as possible – I’m promised the use of a bead blaster to clean up the castings but that won’t be until next week.
Back soon after that then
Regards - Ramon