Piaggio Skipper (leader 125 engine), bottom end knocking?

I heard these engines go on forever, but my old (10K plus miles) engine had developed what sounded from experience like a big end knock (loud at low idle, fades with revs), and had become quite sluggish. I swapped it for another engine from the same year (2004), but from a scoot with only 60 miles on the clock - the engine had likely done much more than that though as it had been an alternative fuel test-bed at a university, but it was clean and OH SOOO quiet by comparison to the original when I fitted it, and was notably quicker both top speed and acceleration.

2,000 or so miles on, and it has developed the same knock, *exactly* the same that is, and it seems to have started getting a little sluggish too, and the noise seems to be getting worse at a noticable rate...

I've heard these engines should do 50K plus on a bottom end so I'm rather puzzled...

Anyone got any insights for me? I've just spent a good deal of time stripping off and replacing all the old body work, lights, forks, switch gear etc. and wheels for the 'new' stuff from the donor scoot and now this, ugh...

TIA for any help folks,

TRS/Shaun

 

DoOoD this engine was immaculate when it went in 2000 miles ago, ran smooth as anything, nice and 'nippy' and quiet as a mouse! Can't be going and buying another s/h engine already, and def. no budget to get another scoot esp. not since we have a baby on the way now. Maybe I should just start saving up for that full Malossi one eh (http://www.scootershack.co.uk/threads/malossi-engine-not-a-cylinder-kit.32029/) should have it by the time I'm about 70 y/o ',;~}~

 

It's still running, just the worrying knock at low idle and slight loss of power and top speed (from max. 70mph indicated down to about 62 or so), and as I said got no budget to spend on this ATM, just really curious if anyone else has heard this same fault and knows what the cause is.

Cheers!

Shaun/TRS

 

my runner did the same, but i had my vario explode at full throttle, which i suspect put the bearings out, my oil light came on when it was idling too. i ended up swapping the engine for an earlier air cooled unit.
one thing that helped mine was some stuff called ZX1 its an oil additive, made a considerable difference to the noise, but the oil light always came on at idle.

 

Have you actually had the top end off yet and checked to see if there is any play in the big end bearing? It's not a difficult job to do, just a bit time consuming. I'd look at the old engine first obviously as it could also be a crank bearing gone lumpy or a clutch bearing if you've swapped parts over from one to the other.

 

Oil and oil filter replaced, chain and tensioner/clearances etc. not checked - too involved for me I'm afraid, and I paid to have a load of things checked on the 'old' engine and all came up as it should be.

I've NOT concluded anything like the engine needs replacing, in fact not concluded anything at all - just trying to get to the bottom of this 'new' engine noise so far. When I get my camera back I'll record the noise and post it here see if it's familiar to anyone.

Cheers!

Shaun/TRS

 

Getting inside the engine is beyond me these days mate - not got the time, the space, the tools or the energy.

BTW no parts have been swapped between engines, not even carb.

For now I'll just have to keep running it and 'see what happens' but as I said in prev. reply when I get chance I'll record the engine noise and post it here.

Cheers,

Shaun/TRS

 

YUP! First thing I did mate but I didn't find anything that sounded the same.

Cheers,

Shaun/TRS