Oil Temp and Viscosity : V-Twin Forum: Harley Davidson Forums

vmann7 · 09-24-2009, 04:22 PM

Hi All, quick question on oil temp,

My 07 FXST with a Fuelpak and V&H big radius pipes just started running hotter after an oil change. I was running 10W30 mobil one and just did a change to the vtwin 20W50 mobil one. Before the O/C I was at 220 on even the hottest days, today after a 30 mile ride, combination highway/suburban with no stop and go the temp went to 240. I did a search and see this is not completely in the running too hot range but I'd rather it was cooler. Does the viscosity have any effect?

One note on the O/C, when I refilled it, the bike only took 2.5qts instead of three. I believe I had a short bus moment and forgot to stand the bike up to completely drain the old oil. I did check the oil flow in the tank and it looks good plus the filter heated up quickly when started from cold so I believe the oil flow is good, did I miss anything here?

Thanks.

Just a little more info, Mobil One said

"The Mobil1 10W30 motor oil should not be used in motorcycle, it is the
improper formulation and the incorrect viscosity according to what HD
recommends. The Mobil1 V-TWIN 20W50 is the correct product but heavier then the 10W30 thus causes more drag which could be the reason of the higher temperature. As long as you are within the operating temps of what HD states is normal parameter, it is fine."

OK, I also checked the plugs and they seem fine, the front a little browner than the rear, I assume since the rear is hotter and leaner.

The air filter on the other hand was dirty, I'm cleaning that as I speak.

03GLIDE_ · 09-24-2009, 06:43 PM

I agree you should not run 10/30 in a harley. While 240* is on the hot side it's not that far away from being normal. My last bike would run that hot all the time. I put 75,000 miles on it with zero problems. I wouldn't worry about it myself. Ride it!

vmann7 · 09-24-2009, 07:29 PM

Actually its "my bad" on the viscosity, I looked on the wrong shelf in the garage, I was running the regular mobile one 20W-50. FWIW getting older blows, ya need reading glasses in the garage, this sucks!

03GLIDE_ · 09-24-2009, 11:25 PM

Quote:

Originally Posted by vmann7

Actually its "my bad" on the viscosity, I looked on the wrong shelf in the garage, I was running the regular mobile one 20W-50. FWIW getting older blows, ya need reading glasses in the garage, this sucks!

Don't feel bad i have reading glasses in my truck, work truck, bike, desk, bathroom, and garage. All drug store cheapies.

TheNowhereman · 09-25-2009, 12:51 AM

People assume viscosity with cooling too much
If you ever have seen the oil in F1 cars, you would freak out.
ITs almost like water; clear and light.
It takes care of an engine that runs most of its life at 18000 rpm.
Heavy weight oils are good for engines with looser tolerances that need some help.
Flow rate counts for soooo much in cooling capacity.
If you ever burnt your finger, you know what Im talking about.
You dont stick your finger in a glass of water, you stick it under RUNNING water.
That constant change of fluid takes heat energy away.
motor are no different.
Always run the lightest oil your engine design can use safely.
IT will give you the best cooling / wear protection and the most HP.
Today's oils have great friction control additives that do a great job.
Don't get sucked into the syn vs. dino oil thing.
If you change your oil / filter every 3k or less miles, your motor will last a long long time.
NWM

blewcrab · 09-26-2009, 04:08 PM

20/50 hd syn should run u at 200....try boiling water then stick the oil sensor in the water ....it should read 220...if it reads more than that,get a new dip stick sensor

davekp · 09-27-2009, 07:57 AM

Quote:

Originally Posted by blewcrab

20/50 hd syn should run u at 200....try boiling water then stick the oil sensor in the water ....it should read 220...if it reads more than that,get a new dip stick sensor

Shouldn't that be 212?

vmann7 · 09-27-2009, 09:58 AM

Quote:

Originally Posted by blewcrab

20/50 hd syn should run u at 200....try boiling water then stick the oil sensor in the water ....it should read 220...if it reads more than that,get a new dip stick sensor

I'll try that, thanks.

vmann7 · 09-27-2009, 01:05 PM

OK the sensor is good, 212 in boiling water.

The last few days when riding at least ten miles the temp only got to 200, of course the air temp was only 65.

The only oddity when I checked the plugs/air filter etc was the air filter. Like I said it was dirty, I cleaned it and re oiled but when I pulled the cover off the three bolts holding the filter to the box were loose. One was backed all the ways out, only being held in by the cover, one was loose and one was only snug from the uneven pressure from the filter being loose.

Knowing very little about computerized fuel injection, any chance extra air was throwing it off? I always thought the more air flow the better.

vmann7 · 09-27-2009, 02:59 PM

OK, just to be on the safe side I changed out the oil, at 10.00 per quart I don't want to be doing this too often. Of course now I don't feel any better. If you look at the attached pics you'll see the difference, should oil darken this much after only 100 miles? Keep in mind I did forget to stand up the bike the first time so some oil was left in it. I'll also post this in the oil section to see if any of the gurus there have any thoughts. Thanks

blewcrab · 09-28-2009, 09:08 AM

I dont think u have a problem

starwalker98 · 09-30-2009, 07:30 AM

my 06 fatboy started running hotter this year after a oil change. i use syn3, always did. only thing i did was change spark plugs. i use to run 180 range now i run 200-220.. my stealership manager told me they changed the oil as he got a bulletin. altho ur not using that, i give up. guess as long as im not at 250 ill let er rip.