Coolant temp light coming on.

[F6Ghostrider VRCC #32501]

A little background first. I live and ride in and around Bakersfield, CA. Summer temps get as high as 108 and the Winter lows in the high 20's. I ride my Dad's 98 CT with 112, 650 miles on her. He's been carried on the to the highway in the sky so I can't ask him.  I ride about 350 miles a week to and from work, usually 9 1/2 to 10 months out of the year. My best guess is that I started noticing it somewhere around last August or September. Speed nor RPM's don't seem to affect when the temp light comes on. It's intermittent and comes on anywhere from 1 to 30 seconds. So in mid February Dad's Valk developed a minor coolant leak. BUT IT'S STILL A LEAK! The first weekend in March I pulled the radiator and replaced the two seals behind the thermostat housing. The thermostat rubber did'nt look good so I eplaced that too. While I had her apart, I tested the stat according to the manual. If I remember correctly it said the stat should start to open around 183 degrees or so. Well, it began opening at 203. I put her back together (even pointing the hole in the back of the stat in the correct direction, . . .yea me!) with new Honda coolant and took her for a test run. It didn't leak until the next day when I got to work. Not bad, maybe 3-5 spots the size of quarters. So every morning for 6 or 7 commutes I would top off the radiator (about an ounce or so). I would and can still smell burning coolant. Well, about the 8th commute, it quit leaking, but I could still smell burning coolant. So my question is, "Do I have to remove the carb bank to change the other 2 seals leading into the heads?" I think that must be where it is/was leaking from. So if the stat is bad, will that cause the light to occasionally come on? Or is it maybe sucking air causing the light to come on? I love his bike and I will be devastated if anything happens to her. Any and all help is greatly appreciated. The readers on the VRCC are the best source of information I have ever seen and read. Thanks to all! RIDE ON!

Jeff

[Patrick]

If a 180-185 degree thermostat starts opening at over 200 degrees, my thoughts are the 'stat is lazy/defective.. That may well be why the lite is coming on.. The coolant temp sensor/switch could also be bad, but, I'm leaning toward the 'stat.. Can't help you with the leak, you just need to locate it and fix it..

[Bobbo]

While I had her apart, I tested the stat according to the manual. If I remember correctly it said the stat should start to open around 183 degrees or so. Well, it began opening at 203.

I'm curious as to how you tested the thermostat.  If you put it into a pan and started heating the water, the thermostat will have a slight "lag" while it heats up.  Also, if you measured the temperature at the top of the water, it will generally be hotter than the bottom.

[F6Ghostrider VRCC #32501]

I tested the stat just like the manual stated. I suspened it using a wood skewer and a bread tie suspended in a 4 quart pan. I started with cool tap water and heated on high until it was completely open. I used a digital spike type thermometer at the depth of the stat. I tried to take out as many variables as possible (that I could think of at least).

I'm kind of leaning towards replacing the stat. It's $30 at the local Honda dealer. Sometimes I'm kinda thrifty, or just old school (ya know, if it ain't broke, don't mess with it).

I'm mostly sure the leak is coming from the tube on the clutch side, as there is/was a considerable amount of coolant sitting on top of the block. I'm just dreading the thought of removing the carb bank. I think I have a sticking float anyway. Might be a good time to pull the bowls and checker out.

Thanks for the input guys!

Ride safe.

Jeff.

[98valk]

its fully open at 203 and starts to crack open at 176-183. that crack is very small and u have to look at it with an eye piece to actually see it crack open.
did u burb the system of air after replacing the coolant?

[Valker]

The Car Quest thermostat perfectly replaces the Honda one for about $5. Jeff K's generic parts.

[Mr.BubblesVRCCDS0008]

Is your fan kicking on when things start to heat up? I found out the hard way my fan switch was bad in houston traffic. Waiting on new switch now I wired my fan up thru a toggle switch to put the wire at the radiator to ground and kick the fan on in heavy traffic. I have temp guage so I can see when she's getting hot and act in advance.

[Valker]

There is a faulty sending unit that does this also. Mine will come on for anywhere from 1/4 second to 15 seconds. When I finally get tired of it happening, I'll replace the $40 part.

[Tundra]

F6Ghostrider, What year and model is your Valk?  (I'll reply tonight when I get home.) Never mind, I reread your post and see the model and year.

The temp light flashing on and off is a fairly common problem with your year. The fix is the indicator unit. It is located under the left side cover. I will try to locate it in the microfische. It worked for me as well as several others I used to ride with. The part number below is from HDL, their link is http://www.directlineparts.com/  you want to scroll down and go to the OEM on-line parts.
Order:
Qty.    Part Number    Price Per Item    Special Order    Product Name
----    -----------    --------------    -------------    ------------
1    38710-MZ0-003    $50.99        No            Honda - INDICATOR UNIT


As far as your coolant leak, I can't help you there. The only coolant leaks I've experienced were at the cap (seal wore out) You may be smelling residual coolant burning off the hot block??

[Tundra]

Bump

[F6Ghostrider VRCC #32501]

I'm pretty sure I burped the system correctly after replacing the coolant. I tried to follow the maual as closely as possible.

Is your fan kicking on when things start to heat up? I found out the hard way my fan switch was bad in houston traffic. Waiting on new switch now I wired my fan up thru a toggle switch to put the wire at the radiator to ground and kick the fan on in heavy traffic. I have temp guage so I can see when she's getting hot and act in advance.

My fan rarley comes on. Mostly in the hot summer afternoons.

What is Jeff K's generic parts? And would you maybe have a cross reference # for that stat?

Good lookin out on the info for that indicator unit. I'll definitely look into replacing that.

I'm seriously thinking my leak is coming from the clutch side seal on the coolant tube that feeds the head. There's nothing else there that I know of that could leak. My cap seal is good. I would see some kind of coolant around that area if it was leaking from there.

Thanks once again for all your input guys. I'll be in touch after I tear into her to find that leak.