Hi, Friend bought a new Montesa 4rt but third time out he drowned it in a river, we got the water out of the air box, exhuast and barrel and thought it would be best to get the bike going and warmed up to get rid of any water left in it (dont know if this was the right thing to do). Surprised how quick we got it going but noticed a light knocking sound, also seemed to lack top end power. My friend is skint after buying the bike so are trying to find out what the problem might be and how much it will cost. Has anyone got any ideas, one guy told us it may have bent the valves through water compression but I thought it wouldnt run at all if that had happened. Any ideas much appreciated and thank you for your time.

Nick

Change both oils and all filters (flush with petrol) .. and ride..... if no noise. . . no problem

Probably best to take it to Sandifords they have a 4RT expert who can put your friends mind at rest

Change both oils and all filters (flush with petrol) .. and ride..... if no noise. . . no problem

I agree. I've never heard of bent valves due to water ingestion. It's possible in some older engines to cause rod, piston or possibly kickstart damage with a hydraulic'ed cylinder, but rare in today's machinery (usually the only way to bend the valve is if it's open, which would allow the water to escape, therefore no built up chamber pressure). Don't forget to drain and add new, fresh petrol to the tank. Not quite sure what it would do to the electronics, but you would imagine those to be relatively waterproof.

Jon

I would think it would be easy to bend the conn rod if you packed the top end with water. Be careful to measure that the piston is coming all the way up to the top, if not, the rod is bent and will break in the middle, wiping out the cases!

Better to save it now than take the risk!