Unless it was drowned in a spotlessly clean creek that will be a big reason for its early demise. It is just pretty much impossible to clean all that sand silt and crap out of the bearings/piston/rings bore with out disassembly.

Shouldn't be that then. I have done the same numerous times and my bottom end was still perfect when i replaced it at about 300 hours. Normally see problems (like rust) when people don't know what to do an load the bike up full of water and take it home for a few days and then off to the bike shop for repairs. drown, fix and run should burn out any moisture.

Normally the air filter prevents any sand getting through to the engine.

Maybe your buddy need gas, used it and replaced it without knowing it was supposed to be premixed

drowned
 

Ive drowned my 200 and 300 and many many hours / years later still good

As said on thumper talk, that bike has been left sitting with water in the engine, maybe by a previous owner. The corrosion in the case where the main bearing sits is severe.
Such a corrosion will not happen in a day or two, not even in a few weeks.

makes sense, why else would anyone sell a 2018 gasgas with only 5 hours!?!?
if you've ridden the bike for 5 hours you will know what an awesome bike it is, but if you are a noob and drown it in those 5 hours and don't know what to do (as mentioned above) you may get into panick sell mode LOL

I've drowned numerous bikes and got away with it.

I've also seen a few pumpkins take a lung full of slop through the filter and fail to finish the ride. One on pull down had worn the rings so far out of spec they wouldn't even hold themselves in the cylinder anymore.

Lots of variables involved.

Hmmm it is interesting - I too thought that a drown wasn't a big deal - Pumped the water out, started it up and continued on.

Drained the gearbox oil and refilled it, did that till it was clean, checked down the intake boot for any debris and it was clean.

I suspect maybe something happened early on in its 5 hours of use before mine, as Doc has said this doesn't happen over night.

I wouldn't be surprised if someone had tampered with my petrol, it was left there for a while.


Funnily enough as well - the ring end gaps on the piston rings are still within spec, one being actually a little tighter than it should be, so that tells me there wasn't a whole lot of debris going into the combustion chamber, so I feel like I can rule out dirt as a cause. The piston however was a bit undersized, another member mentioned that perhaps an undersized piston could cause some combustion to get past the rings and have some detonation on the underside of the piston (like mini combustion events happening below near the bearings) perhaps thats why they were quite dry in there?
I would have thought the rings would stop it but perhaps it can happen?

As the underside of my piston had quite a bit of burnt oil - then again all this could have just been caused by lack of oil in my gas, though if that was the case, wouldn't the top end seize up ? Surely I would have had some pretty severe scoring on the cylinder if that was the case.

Sometimes I would hear a little bit of "pipe bang" when the bike was cold and warming up, I probably should have paid a bit more attention to it.

The 2018, possibly other models also had main bearings that have plastic cages. They do fail in the 100 hour range consistently. Don't know why GG would do this other than to save a dollar. They were going through a financial crunch around that time. I've got a friend with one that just got his back together. Get the metal cage bearings to replace with.

Same issue, main bearing fail, 65 hrs...2 hrs after new piston, which is useless now. Once apart, will do the conrod also while at it, since this is how freshly honed cylinder looks like now.

It is very important that after drowning a bike you need to get the water out and get it running ASAP!! Change trans trans oil ASAP too.