Engine Temp

[CARider49]

I thought I noticed something funny a week or so back and then I was able to confirm it when I rode to work one morning this past week. We have cooled off here in CA and my morning commute is generally done in 55 degree or lower temps. I have a temp gauge that will rise to the point that I would expect the thermostat to open and then when it opens will drop once it drops it will rise again. This cycle repeats for the entire 15 mile trip to work. I know she runs cool but should I be concerned about the constant temperature fluctuations causing undue metal fatigue?   

[Alpha One Nine]

I know what you mean on the temp fluctuations.  My KLR650 was really bad until I installed a Thermo-Bob.   Now it gets to proper running temp quickly and there is no fluctuation unless it’s hot out and I’m climbing steep trails low speed.
It’s a very popular item in the KLR community and some have said their oil consumption has been reduced since adding it.
Watt-Man has one for the older Connie now and I'm considering geting one.

http://shop.watt-man.com/Thermo-Bob-1-Universal-Kit-with-One-Inch-Fittings-TB1.htm

[T Cro ®]

Considering that these bikes have exhibited this characteristic since new (86) and many of those original bikes are still on the road today I'll go out with saying that while it is an odd behavior it is not harmful to the longevity of the motor. An easy way to help stabilize this would be to block off part of the rad with cardboard.

[CARider49]

Thanks Tony - That's all I needed to hear. I am glad I am not the only one this happens to, thought I was loosing my mind for a few when I first saw it occurring.

[T Cro ®]

Thanks Tony - That's all I needed to hear. I am glad I am not the only one this happens to, thought I was loosing my mind for a few when I first saw it occurring.

Yep it is a fairly common annoyance... Another option is to replace the T-Stat with one that has at least an 1/8" bypass hole in the body this may help reduce the cycling.

[connie_rider]

In some past discussion I recall seeing a note about drilling a small bypass hole in the T-stat.
My memory sux but I thought it was done to ensure you didn't leave trapped air in the cooling system when changing coolant?
(Tony correct me if I'm wrong)

Bottom line; Ithink it would help  both the trapped air and temperature cycling.

Ride safe, Ted

[JDM]

In some past discussion I recall seeing a note about drilling a small bypass hole in the T-stat.
My memory sux but I thought it was done to ensure you didn't leave trapped air in the cooling system when changing coolant?
(Tony correct me if I'm wrong)

Bottom line; Ithink it would help  both the trapped air and temperature cycling.

Ride safe, Ted

It also keeps the water pump from dead heading against a closed thermostat and puts less strain on the o-rings thus cutting down on potential leaks in the system.

[RFH87_Connie]

From the parts conversion chart, I got a Stant brand thermo from a 1983 Hoda Accord (192 or 195 degree) and it works great.  Cheaper, and it has a weep hole already in it.  If you do replace the thermo, order at a minimum, both o-rings before you dig into it.  the large one is usually the consistancy of black bubble gum if it is old.  They would be 92055 and 671 in the picture below.  92055C is the o-rings for the cooling log to the head.  Murph sells a kit for these for a great price.

The big o-ring:
http://www.murphskits.com/catalog/product_info.php?products_id=435
Cooling log set:
http://www.murphskits.com/catalog/product_info.php?cPath=1_105&products_id=428

It you think your fan switch is suspect, you can get one from a 1991 Honda Civic DX.  Also inexpensive.  when you change this (quickly) you only loose a few ounces of coolant, so you don't need to drain the system down.  If you want OEM, Murph carries it too.
http://www.murphskits.com/catalog/product_info.php?cPath=1_107&products_id=484

I mainly added this info for others reading this thread.  Sounds like you are OK with your gauge (which is pretty normal).

Now, watch out for hurricane Sandy!

[F-106]

I had the same thoughts when I got mine a few years ago. I too ride in calif and the temp changes play havoc with the bike from season to season. Mine ran this morning to work next to the first line white line all 30 miles. It did clime a bit once off the freeway but in the 50's like we are having thats just were these Connies like to run.

[SteveJ.]

RFH 87, I think you will like the way the hotter t-stat works out for ya. I put one in a coupla years ago and like how it functions, keeps the engine a bit warmer in the cold weather.

[RFH87_Connie]

I put it in last spring (1.5 year ago) also to help keep the engine a little hotter which I think should make it a little for fuel effiecient and keep moisture out of the oil better.  I did it all at the the same time my fan switch quit working.  Coolant, switch, thermo, log o-rings, hoses, all at once.

[timsatx]

I wouldn't think in a place like South Texas you would want a hotter thermostat. It rarely gets cold enough for that to be an issue. Up north I could probably see it.