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Andy B · 21-12-2018, 03:25 PM

Hi guys,

Been putting this job off for nearly two years now. The missus rides the monster whilst I follow behind on the Guzzi normally (and I get to take it out when she's not looking)... Once thing I have noticed is puffs of blue smoke when she pulls on - not all the time, but more than i'd like anyway.....

Last few months its been a big boggy when pulling on too - I assumed crap in the carbs, plug starting it always a pain in the ass....

So, I thought I'd pull the heads and barrels, expecting to replace the rings and hope the barrels are ok...

Front cylinder is definitely the worst culprit - was a right bugger to get the barrel off as well as the case studs had built up a fair old bit of corrosion (vertical cylinder just pulled straight off no hassle), and the head was carbon'd up something rotten....

Started cleaning with a wire brush to get the worst off...

Leak down check with some carb cleaner failed...

And top of the inlet valve was coked up too...

So anyway, I've cleaned up as best I can with the valves and started lapping them back in - planning on getting the heads and barrels vapour blasted so not going to use too much elbow grease on them... but taking the piston off, any tell tales for checking worn rings?

I bought a set of rings from Germany via ebay after a bit of research and i'm not sure i've gotten the right things... (https://www.ebay.co.uk/itm/291624459815)

these are the new rings, but they are slightly different... I'm assuming i'm not going to be lucky enough that they are interchangeable?

Also noticed some light scoring on the piston skirt, there's no major scoring on the barrel, but again, there are some slight marks...

At least the piston cleaned up nice enough....

And then just to add a bit of drama - bloody cam belt tensioner guide bearing on the front cylinder decided to grab some ali right at the tip and damaged the thread all the way down (D'oh!)

I'm hoping I can re-dress the thread or at the very worse use a timesert....

So big questions i guess are - piston rings - If they're the wrong'uns - is there anyway i can tell if the old ones are even shot? and If i can't sort out the threads in the barrel - does anyone have a spare horizontal barrel going?

21-12-2018, 03:25 PM	#1
Andy B Registered User Join Date: Sep 2014 Location: Bromborough Bike: M900 Posts: 94	Heads off Hi guys, Been putting this job off for nearly two years now. The missus rides the monster whilst I follow behind on the Guzzi normally (and I get to take it out when she's not looking)... Once thing I have noticed is puffs of blue smoke when she pulls on - not all the time, but more than i'd like anyway..... Last few months its been a big boggy when pulling on too - I assumed crap in the carbs, plug starting it always a pain in the ass.... So, I thought I'd pull the heads and barrels, expecting to replace the rings and hope the barrels are ok... Front cylinder is definitely the worst culprit - was a right bugger to get the barrel off as well as the case studs had built up a fair old bit of corrosion (vertical cylinder just pulled straight off no hassle), and the head was carbon'd up something rotten.... Started cleaning with a wire brush to get the worst off... Leak down check with some carb cleaner failed... And top of the inlet valve was coked up too... So anyway, I've cleaned up as best I can with the valves and started lapping them back in - planning on getting the heads and barrels vapour blasted so not going to use too much elbow grease on them... but taking the piston off, any tell tales for checking worn rings? I bought a set of rings from Germany via ebay after a bit of research and i'm not sure i've gotten the right things... (https://www.ebay.co.uk/itm/291624459815) these are the new rings, but they are slightly different... I'm assuming i'm not going to be lucky enough that they are interchangeable? Also noticed some light scoring on the piston skirt, there's no major scoring on the barrel, but again, there are some slight marks... At least the piston cleaned up nice enough.... And then just to add a bit of drama - bloody cam belt tensioner guide bearing on the front cylinder decided to grab some ali right at the tip and damaged the thread all the way down (D'oh!) I'm hoping I can re-dress the thread or at the very worse use a timesert.... So big questions i guess are - piston rings - If they're the wrong'uns - is there anyway i can tell if the old ones are even shot? and If i can't sort out the threads in the barrel - does anyone have a spare horizontal barrel going?