[Ducati] 748 overheating

[Moto Star]

I just have to say it.....

That was a great post Larry!

Reet
'98 Honda RS125
  (CCS/USGPRU #67)
'01 748S
'96 900ss/sp
'76 BMW R90cafe
'72 Yam RD200/400
'71 Yam R5
'73 Kaw S2350cafe
'88 BMWK100RS (for sale in Italy: 
http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&item=230008335759)



>From: Larry Kelly <ljkelly at san.rr.com>
>Reply-To: Ducati Owners Group <ducati at ducati.net>
>To: Ducati Owners Group <ducati at ducati.net>
>Subject: Re: [Ducati] 748 overheating
>Date: Thu, 13 Jul 2006 08:26:14 -0700
>
>
>On Jul 12, 2006, at 4:30 PM, S Rudloff wrote:
>
>>I have a 2001 748 that overheats the red light does not come on  neather 
>>does the fan. what is the regular temp that it should run at.
>
>TOO HOT?
>
>The temperature gauge displays the range of expected operating  
>temperatures. The midpoint is selected to correspond to the nominal  design 
>operating temperature.
>
>If you're at speed on a warm day you should expect to see  temperatures 
>between the gauge midpoint and three-quarter point,  (usually 100°C for 
>water-cooled bikes) where the maximum gauge  reading indicates the boiling 
>point of a pressurized 50/50 mix  coolant, the temperature at which the 
>pressure relief cap will likely  discharge coolant to the overflow tank.
>
>When you get stuck in stop-and-go traffic, the temperature will  naturally 
>begin to rise because now there is reduced airflow through  the radiator 
>cooling fins. During these traffic conditions,  temperatures in the upper 
>quarter of the gauge display should be  EXPECTED and not necessarily be a 
>cause for alarm or an indication of  cooling system problems.
>
>If it gets too hot your Ducati's fuel injected engine management  computer 
>automatically retards the engine ignition timing so as to  run well at this 
>higher temperature, but at a reduced power output.
>
>An engine should be at its design operating temperature to make good  
>power. Higher temperatures are more thermodynamically efficient, but  run 
>at too high a temperature and you exceed the thermal expansion  design 
>basis of critical components and raise fuel octane requirements.
>
>Ducati fuel injected motorcycles use engine management computers  
>incorporating a coolant temperature sensor to retard the engine  ignition 
>timing to compensate for any increase in octane requirement  when operating 
>temperatures increase. Retard the timing and you  reduce power.
>
>Most stock-engined sportbikes are designed to produce their best  power 
>when coolant temperatures are close to 200°F/95°C.
>
>Duane Mitchel reported that he ran a series of tests to establish  optimum 
>running temp for a race bike and found that (185F) 85ºC is  perfect. Over 
>that, they lose horsepower fairly quickly (down about  15 HP at 100ºC) and 
>below that the same (down about 6 HP at 65ºC).
>
>Your first step is to straighten out any bent radiator fins and cover  them 
>with protective screening.
>
>This is an easy do-it-yourself project for a superbike. After you  
>straighten any bent radiator fins, cut a piece of aluminum window  
>screening to fit leaving 4-5 inches on top to make some tabs to bend  over 
>the top and back of the radiator. It conforms easily to the  curved 
>radiator shape and the wind pressure holds it firmly against  the radiator.
>
>Remove the V-shaped lower cowl and attach another piece of screen to  
>protect the oil cooler. Fasten it to the back of the panel with small  
>self-tapping screws and washers at the four molded holes. Silicone  
>adhesive or double-sided tape also works.
>
>Any screening will reduce airflow somewhat, of course. The smaller  the 
>mesh, the more protection against smaller debris. I can only  offer that 
>common aluminum window screen works fine in desert  temperatures with no 
>noticeable effect on 916 coolant temperatures.
>
>I wish I thought of it right away before fin damage occurred. After  20,000 
>miles, I still haven't had to replace it. I used window  screening simply 
>because it's cheap to replace and has a fine-enough  mesh to spread out the 
>impact load (and keep bugs out), but if you  prefer something different, 
>check out the McMaster-Carr web site.  When they sell mesh screening, they 
>define the percent open area that  tells you about its ability to flow air.
>
>If you want even lower coolant temperatures, change from a ethylene  
>glycol/water 50/50 coolant mix to WaterWetter and water, but I  caution you 
>that this will often make the bike run at temperatures  below the gauge 
>midpoint, too cool for efficient operation.
>
>
>Larry Kelly
>'95 916Ducati On Line thanks its sponsor and friend, Cycle Cat, maker of
>some of the most beautiful products ever for Ducati's.
>Visit http://www.cyclecat.com/
>
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