Initially getting the bike running was down to carb set up which has all been sorted now. The bike is running roughly again due to the oil leak fouling the plugs. In short, two completely different issues.
Essentially, yes. The bike ran fine until the oil apparently worked its way up past the piston into the combustion chamber. New pistons ordered so well wait and see!!!!
When you send the barrel in hopefully they will discover something prior to refurb, it would be nice to know the root cause.
I'm back with an update... Ordered, received and installed a set of JE pistons, and following installation, swilled out the exhaust pipes with meths in order to remove the majority of the oil deposits that were still in there. Turned her over with the kill switch off to build some oil pressure prior to ignition. Kill switch on choke on, and off she went. One pot first that the second chimed in almost straight away as i knocked back the choke. Ran her for 5 mins to burn off the oil and rebuild deposits then shut her down. Had another good look over and fired up again. Guess what? zero smoke no leaks nothing! Having congratulated myself on a job well done, I sat with a brew and had a good look over the pistons I had taken out. Although the two pistons are both Airas they are different patterns and different model numbers. One has a three piece oil ring (vertical cylinder) one the older ring and spring arrangement (horizontal). The front (older) piston also weighs approx 50 grms more than the newer rear cylinder piston quite a difference in terms of balance. I have a sneaking suspicion that the front Arias piston was one that was present when the bike originally shat itself and has never been touched. What I do know is that following the "explosion" the engine was dismantled, inspected and rebuilt so the piston is likely to have been within tolerances and ok to reuse. The components were replaced in the rear pot and engine rebuilt. The bike ran fine and was taken abroad on several trips without incident. Then the oil leak started all the evidence pointed to the rear pot being a fault hence the replacement head, cylinder, and apparently a single unmatched piston. So it now appears that the rear pot was fine all along and the issue has been the horizontal cylinder and piston at fault. Now iv'e replaced both pistons with lovely shiny forgings I'm well pleased. Either way, I don't care as my bike now runs smoke free and is oil tight. Its been emotional but the piston kit appears' at the moment to be the best, £290 iv'e spent. On the upside, I have had an opportunity to Inspect oil gallery plugs, bearing conditions, check for freeplay, bore condition, replace valve stem oil seals, o'rings, gaskets and give her a wipe over. All that remains is a Test ride and to run her in again like a new machine. Phew!
Glad you’ve got it sorted, Boris has even been good enough to lift the lockdown enough for you to run it in, so have you figured out why you were getting oil in the rear cylinder? (If I’m remembering correctly)
From what I can tell, the oil tracks may have been blown up into the rear cylinder but i'm speculating. I really cant be sure, suffice to say the oil traces led me on a merry dance for quite some time... Who knows for sure? it may have been both pistons playing up and just needed the whole job doing rather than pissing in the wind guessing. Suffice to say ill be keeping an eye on anything unusual. On another note, Iv'e just treated her to some new clutch plates.
Fingers crossed and tentative Congratulations Dave, finding the odd pistons is pretty crazy plus modern oil scraper rings huh.. it's the future..
Update. New clutch plates and steels in. Clutch bled, Chain adjusted, tyres kicked, 22 mile gentle test run... she is oil tight strong and extremely responsive. Still starts, albeit temporarily, on one cylinder on choke but otherwise spot on. No longer a "hangar Queen" . Thanks everybody for your input. Just need to re torque the heads and adjust the tickover down a tad and shes a good un. One thing I have learned throughout this experience, is not to go down rabbit holes when following oil trails. I never even considered the front pot as being the problem as it had never come to the fore as being the issue. The piston replacement exercise appears to be the final piece in this very puzzling issue which at times was like trying to peice together the picture of the tiger on the frosties jigsaw puzzle.
Its official, shes back! 110 miles of the running in process completed. The engine is strong long legged and beautifully fueled. response off the throttle is crisp and clean and she rolls on without hesitation. Not revved her past 5500 yet but at around 500 miles it will be an oil and filter change and then the shenanigans can progress a little more. I forgot just how much fun this bike is. I'm so pleased....
There’s something about them isn’t there, so basic I think maybe that’s it, no nonsense, nice handling, torquey, love riding mine.
