So finally I fixed the cold running temperatures during autumn, winter and early spring. With COVID keeping me from going to the office this winter, I took the shot and ordered a second hand 2010 Dorsoduro thermostat (part no. 834232). This thermostat has a opening temperature of 85oC instead of the default 65oC. It was almost a drop-in replacement for the existing thermostat. I just had to order a straight piece of radiator hose that has a 19mm ID, instead of using the 22mm ID. This piece replaces the piece that runs from the thermostat housing to the rear cylinder. It is a bit of a snug fit on the cylinder connection, but with some cooling fluid it slips on just fine. The most painful part is getting the old thermostat out and the other one in. It's just suspending mid-air and held by the radiator hoses, but it's a real tight fit to get it through the frame and connect the hoses back up. Normally you'd have to remove the petrol tank, airbox and everything else in between to get to it. Anyhow, I've driven it in 6oC ambient today and temperature climbs quickly towards a comfortable 86-90oC. This is exactly the 20oC difference I would expect compared to the old thermostat. I noticed a lot smoother driving in these ambient temperatures compared to before. But that would make sense because it now switches to the more lean fueling map at 82oC. Imho this is how Ducati should've designed it for north European countries. Now we wait till Dutch summers that hardly ever exceed 30oC ambient to see how it holds up. But since the thermostat is fully open at 85oC it should not behave any different than before. The radiator(s) are more than capable for keeping this machine chill.
Seems like a very worthwhile mod - would be quite interested to try something like that on my Enduro.
Cool running is a complaint with nearly all water cooled Ducatis. This mod should be doable on most that use the the same thermostat, which is nearly all of them from the S4 to the Monster 1200. https://www.bike-parts-ducati.com/ducati-motorcycle/assignment_spare_parts/55340041A
I still can't comprehend why Ducati (and Aprilia) would use 65oC thermostats. It has more downsides than upsides for most people. Sure, you get a bit more headroom before fans kick in when you are in front of a traffic light, due to the thermal mass. But contrary what many people think does it not help in driving conditions. If it heats up from 85oC to 110oC in driving conditions, it will do the same from 65oC. It's bad for your lubrication, because your oil will never hit 100oC+ either (this was biggest problem for me). But it's also bad for mileage and drivability because of the richer fueling. I hope many more water cooled Duc owners will attempt the same thing. It's a cheap mod that pays itself back in consumption and maintenance costs.
Do you know what sort of improvement to expect in fuel efficiency? I'd imagine the richer running may not be so good for washing oil off the bores, so long-term durability of the engines could be affected. I'd actually very much like to try this myself.
An interesting comment. My Multistrada has been running rich for about 30,000 miles and the horizontal cylinder bore wear that lowered compression, is why I decided on an engine rebuild. Note to self : get the bike dyno’ed again. Andy
Could be worth a go, my 13 runs rich, black around Termi end can tells me that, plus the smell. Engine rarely gets above 60 degrees this time of year.
Hard to say right now. It all depends on riding style and other parameters. I think for me it's about an 10-15% improvement. Maybe even more? I noticed that the displayed average fuel consumption was way off during winter times, and only a little off during summer times.
I’m actually debating running the bike with something over the radiator, to see if I notice a difference. It might be possible to slide something under the Evotech radiator guard.
I did this last year, duct taped about 60-70% of the radiator and all of the oil radiator. It did eventually help, but did not really heat up as fast as it does now. Even the cold passive air (no driving air) can be enough to really cool down much of the air. Covering it up all around will probably help a lot because it will keep the heat trapped inside. Biggest downside for me was that the fans were not able to keep it cool any longer when the radiator was covered. They were not able to suck through enough air when it's (partially) covered. But doing anything is better than doing nothing at all! Just keep your eye on the temperatures.
This is something we have discussed in the past and was always a real bugbear of mine. Its great to see that someone has actually gone ahead and carried out this mod and with such success.
Good for you, couldn't agree more. This is a mod I wanted to try but never actually did, even though Derek actually pointed me at what is probably exactly the same thermostat you are using. More power to your elbow. More power to your elbow.
I raised this mod with my dealer and was told that mixture mapping is more complex in terms of inputs than just temp so they wouldn’t recommend changing the stat cut-in point. I think I may have been fobbed off but am open minded to the debate.
It would have been useful if they could have told you at what coolant temperature the ecu ceases to provide a rich mixture, the suspicion being that the oem thermostat is forcing the engine to run at a temperature lower than that cut-off point. If so, this means increased fuel consumption, maybe some power loss and maybe some oil contamination.
Decided to follow in Fricorico's footsteps and with a coolant change due, decided to fit the Aprilia 834232 thermostat. As described very tricky to fit with the change in pipe diameters, but can confirm it's achievable, just needing the new pipe for the rear cylinder (19mm ID, cut slightly shorter than original to 140mm long to accommodate the longer stat). Parts used ... Ebay for the Aprilia Dorsoduro thermostat Part number 834232 and for the 19mm ID tubing Prior to installation, my 2013 Multi would run at 60oC, unless stuck in traffic. Ticking over in the garage, the new stat appears to be opening at 80oC, holding at around that temp until the radiator heats up, then gradually rises to just over 100oC when the fans kick in and temp drops. Took for a test run today at 8oC outdoor temp ... in town, appears the stat is working and maintaining 80-82oC. This dropped on the road to between 70 and 80 - I guess due to the oil cooler working and the cold air. No black on the exhaust tip on return, so looks to be running leaner. Will update with any change in mpg once the weather improves. Overall - a worthy mod IMO Pic of Original (smaller stat above the replacement) And the coil removed to gain access to the stat behind
My own bike is a 2007 1098S full 70mm exhaust system and race ECU, which I bought last year with just 20,000 miles, recently serviced with new plugs. Within 300 miles the oil level had fallen from the top level mark to the bottom mark and dropped onto one cylinder. The plugs were both completely oiled up. Out came the engine and I found both bores lightly scored and dark grey in colour, along with a fair bit of piston slap. Re-bore/re-plate along with new pistons and rings sorted the problem. However, the bike now runs very cool typically 60C – 65C on the open road with an ambient temperature of 20C, but I just rode 200 miles in 10C ambient temperature and the coolant was in the low 50s – rising only in town or slow-moving traffic. My concern now is that running cool and rich could damage the bores and rings again although from my research it appears the bigger risk appears to come from idling the engine with a rich mixture. “If an engine is allowed to idle in an overly-rich condition for as little as 30 minutes, this can cause sufficient cylinder wall damage where the wall may exhibit a dull, dark grey color. If this occurs, the engine will likely require complete disassembly and fresh honing.” Source https://auto.jepistons.com/blog/how-to-break-in-an-engine Long story short, it is important that we run our engines in the correct operating temperature range and it amazes me that it appears Ducati do not use a thermostat which can control this properly in all the ambient temperatures the bikes encounter. – I’m off to get the Duct tape out.
Are there any owners on here that have left it as it is and done high mileages without issue? My DVT runs at 60-65 on the open road like others do, but still gets 48 mpg on average despite my sooty exhaust tip..
