Yamaha TRX850 Enthusiasts Forum

What going on here?

Just run her up and there is coolant leaking from the hole in the l h cylinder. Why? I though this was a spark plug drain?

Never noticed it before - is it anything to do with looping the carb heaters together for FCRs? It almost seems to pump out?

I have my suspicions but would welcome a few replies.

Looping the carb heaters might be the cause if the loop is about the cam cover... (Also, if I rememeber correctly, the carb heaters come off a piece of metal pipe coming out of the head so a leak there would allow coolant to pool around the plug caps). Pull the tank and check your hoses... "Pumping out" doesn't sound very good though... I don't think there is any relationship to that hole and the head gasket though but to be honest, I was in too much of a hurry putting my engine back together in time for last year's race to even bother checking...

Thanks Max

I agree (or at least I think and hope) that it's not the head gasket (this ones only been on for 1000 miles or so in any event) but what bugs me is why it seems to be pumping out.

Every 10 seconds or so, it seems to push out so coolant - will go and leave it runing for a bit to see if it stops. Maybe just a build up where it has been standing for a few days?

Anyone else got some thoughts?

OK then - just left it running and I've found the problem.

One of the carb heater pipes is leaking and the coolant is draining into plug holes (and then being thrown out)

Couldn't see that as the bike was wet before from being cleaned.

Phew! I'm a happy bunny now

Probably the "pumping out" was whenever the thermo cracked open...

Glad all is good!