I have had trouble with the 1050 suddenly dumping its coolant out of the overflow (and once down my leg) . The rad cap was replaced last Sept and it behaved until about six weeks ago when the scalded leg incident occurred whilst sat at lights. I replaced the cap again and it only lasted until last Thursday when it did it again although less violently. The thing is, it releases all the pressure in the system, this allows the water to boil as it is almost certainly at 100c or more as the fan doesn't cut in until 103c. Lings are sending me another cap and although she said they are not aware of a problem but they have sold 30 so far this year which seems rather a lot for an item which should last the life of the bike. I have looked at a 955 manual and see that the fan on those cuts in at 95c and I'm wondering whether to reduce the cut in temp on the 1050 and if so what too. Anyone who has had experience of this problem, your thoughts will be gratefully received.
Don’t want to alarm you too much but when my 955 started spewing the coolant out of the overflow it turned out to be a leaky head gasket. The water jacket was getting pressurised by combustion gasses. I think it had been getting worse for a while until I had it on a dyno and it properly blew. When I stripped it down, the head had warped slightly (about 5 thou) so I had it skimmed. No problems now, the coolant level is staying spot on at MAX in the expansion tank
WATER boils at 100 - non-pressurized COOLANT (50/50 mix) boils at 108C - and when under pressure (std cap is 1.2bar) it would raise it further to over 118C BP No, a 955 is also fan-on temp at 103C as std. Several things to check: 1. Does your fan actually run? And are the blades in good shape, not twisted/melted? Can you spin it freely by hand? 2. Is your radiator clogged with crud? Thoroughly wash out the debris if so, to ensure good air flow through the cores. 3. You need to ensure you have no air pockets in the system - very easy to get these after a fill - I always run to temp where the thermostat will be open (about 85C) then shut motor off, allow to cool adequately then top it up. 4. Is your pump OK? If doing a flush anyway, it's good just to check on the condition of the vanes and again ensure the impeller moves freely. 5. Ensure your Thermostat is actually opening - if necessary remove it and test in a pan of water bringing it up to boil - if you have a thermometer great, otherwise just bring water to boil by which time it should be fully open a fair bit in advance of that. The engine should run comfortably even up to 103 - you can reduce the fan-on temp with TuneECU, but that will just make the fan run more frequently - if you already have a coolant-puke situation it is unlikely you will resolve with a lower fan-on temp.
To be fair to KG @D’Ecosse, my Triumph manual for a 955 (up to 2001) does state fan on temp as 95 degrees. The Haynes manual states that it’s 103C from 2002 on.
Yes - that is indeed what it says in the gen1 manual - however that is NOT the actual case; indeed for the T509 & T595, the fan-on temp is even higher at 106C Not the only place the manual is wrong Do you have TuneECU @freck? Your Daytona of course has an analog temp gauge - but you can read the actual temp in TuneECU and see exactly where it cuts on - as well as being able to see the fan-on temp value in the MapEdit Screen already anyway (it's actually 100 for a Sagem MC1000 00-01 S3/Daytona); 2002+ 955 Triples are 103.
My diagnosis for what it is worth, is that crap is being drawn back out of the expansion tank and lodging under the valve, preventing it from sealing and causing a lack of pressure in the system. Coolant then boils in the head after the engine is switched off and overflows out of the expansion tank. I've flushed the whole system out and cleaned expansion tank as best I can and all seems well. Ran it until the fan cut in and switched off with no dramas. I'm just wondering what I can use to dissolve the rest of the crap out of the expansion tank. I tried kettle descaler but it didn't do much.
I used hot water and caustic soda to clean my tank, scrubbing with a long handled brush. It got rid of the brown sludge that was caked in the bottom of it. Just make sure you wear gloves and eye protection
