Napa thermostat (what did I do wrong this time?)

While the coolant was out for that nightmarish valve adjust, I put in the Napa thermostat. It fit great, and it has a much smaller spring than the stock one. The install was trouble-free, all the o-rings were in good shape and Lankee helped me remember to use lots and lots of vasoline lube. It's important. :biglaugh:

But the bike still goes to to the red on the gauge before the fan turns on. Just like it did before.

I replaced the coolant by the manual, is there a chance I missed something? Like, could there be an air bubble or something? On my Concours you have to watch that when you put the coolant in, is why I ask.

Anybody else put on a Napa thermostat? Did it change anything for you, because it's still letting my Vmax get way too hot.

It's not so much the thermostat as the temperature sender that regulates when the fan comes on.. That sender is located behind the right-hand scoop.

But before you go tearing into the sender, a couple of things:

- when you did your valve job, did you take the opportunity to flush your cooling system?
Often a clogged up rad is the culprit, and a good flushing agent followed by copious amounts of fresh water will clear things out.
- the water temp gauges on our bikes aren't always the most accurate. They can sometime be a little optimistic..
- the Max usually runs 'warm'. My '86 sits at 2/3 of the way up all day on the highway, but as soon as I'm in traffic it'll shoot up and the fan kicks in. I do have a lower temperature switch fitted though, but I don't think it's such a good idea.

CB, do you know a guy with a lazer temp, may be a good idea to verify it's not just a 'trick' gauge lying to you.

Did the same thing happen before the valve job?

This Vmax had 31k miles when I got it, within a week I did a radiator flush. I did everything motor-related I could think of, as fast as I could, because I had no service records and wanted clean everything in my bike to start all over with. What was in the radiator was very clean and it was obvious from the hardware that this flush had been performed before.

Why do you think the manual switch is a bad idea? I was going to do that next...it gets very very hot here in GA...

Danny as a matter of fact I can take the bike to my buddy who had the '86, he has one of those high-speed laster thermometers. What temp am I looking for?

Should I install an oil temp guage or something?

coffee_brake said:

This Vmax had 31k miles when I got it, within a week I did a radiator flush. I did everything motor-related I could think of, as fast as I could, because I had no service records and wanted clean everything in my bike to start all over with. What was in the radiator was very clean and it was obvious from the hardware that this flush had been performed before.

Why do you think the manual switch is a bad idea? I was going to do that next...it gets very very hot here in GA...

Danny as a matter of fact I can take the bike to my buddy who had the '86, he has one of those high-speed laster thermometers. What temp am I looking for?

Should I install an oil temp guage or something?

Click to expand...

Gonna have to defer you question to more knowledgeable folks Jenn, but I would guess 195 or so, just a guess tho.
I put on oil pressure gauge on, that will give you a lot of information that is related to engine temp also.

I put a manual switch on, but actually to disable the fan!

That's because I have this lower temp switch installed (187.5 is where it kicks in I believe), and because of it my fan would basically be on all the time once the engine's warm.
It sounded good for the Florida heat, and my temp gauge would never go above half-way, but
I found that since I installed the manual override to turn it off while doing 80 mph+ on the highway, my mpg increased by 10 miles per tank! My battery's also happier about it..

Hi CB...

One of the first things I did as a 'mod' was to install a manual fan switch...its a 'flat-rocker' type, with a small red led light on the top, so you know for sure when it's 'on'...placed on the l'side top of the neck cover.

Mine also, got way up in the 'red zone' often when in traffic, or slow riding conditions before the fan would kick on...that just seemed wrong to me...but rather than changing thermostat, I simply installed that switch, and when the needle drifts up a little over the 'halfway mark', reach down and engage the fan... disengage when you build enough road speed to let it cool normally.

On our hottest, humid, FL summer days, the temp always remains stable now... Cheap n' easy fix... Switch from WalMart automotive was about 3.50 or so, and a couple of those easy clamp-on connectors to run jumpers from the stock fan switch over to the manual one.

Philthy

I'm going to have to be the voice on the other shoulder.
Not trying to confuse you Coffee.
Just trying to set your mind at ease.
I spend almost everyday day in an hour long commute. And in the summers, it is the extremely hot Florida heat and stifling humidity, stuck in stop and go traffic twice a day.
And yes my temp gauge gets to the top of the black line, but has never gone over into the red. And I have done nothing as far as switches and thermostats. It's all bone stock with over 30,000 miles on it.
If you want to cool the motor down for comfort reasons or for peace of mind, by all means do it.
But in my opinion... If it's not getting into the red your fine, it's not something I would be greatly concerned about.
My motor is still good and strong. It's putting out a RWHP of 107.2. Which beat out 2 other stock VMax's at the dyno shootout. So by letting it get to the top of the black line on a regular basis, has had no ill effects on my motor.

Now the one thing I did do is switch to engine ice for coolant. And the only difference I noticed is that once I get moving out of stop and go traffic the temp comes down faster than when I had the regular coolant in my Max.

What oil weight are you using? I noticed mine generally runs warmer with the thicker weight oil.

Thanks all, I'm listening...

I'm running 10/40 non-synthetic, just changed it this morning after the fiasco with the valves (shattered the drop light bulb in the open top end, yikes! Figured maybe there was powdered glass running around in there and was worth the peace of mind to change it).

What would be the correct operating temperature, and what is the top limit? I.e, just how hot is OK and what temp is too hot?

From what I have seen, the gauge isn't that correct. I have had two Maxes and the temp seemed to vary. One of my friends has a completely stock 2006 and his gets close to or into the red every time he rides. We compare temp gauges and his is always at least an eighth to a quarter inch closer to the red than mine in exactly the same riding conditions. There are now 5 in my riding group (down from 7) with Maxes for their daily "fun" rider and all have varying temp gauges with none seeming to have a overheating problem. Check that little drain valve on the tube on the lower half of the front of the engine to be sure it is in the right position. It is difficult to see the mark to set on.

It gets really hot here in Texas so I added the manual rocker switch to control the fan also. It does not affect the automatic function of the fan but you can turn the fan on early and it does help keep the temp down. Really haven't used it that often though as I don't ride in slow or rush hour type traffic often.

From the sounds of what you all have to say, putting a little switch on there would do no harm and make me feel better in traffic. The day I brought her home is was through Atlanta rush hour on the interstate. By watching the temp gauge climb up and up instead of the road, we nearly didn't come home at all!

I can't find a small, high-quality switch around here, I'll have to look.

And I've never installed one like this, that makes a jumper in the circuit. I know it's simple but...if anybody has pics or a diagram I'd sure love to see it.

There's a fan on the Vmax?.:ummm:........JK,...
It actually scared me the first time It came on ,..it was about 26c (79f),..and i was cruising around town before going home.
At a stop light i heard a sound and thought "WTF"...Ah,....sounds like the fan...the gauge was up round red , slowly dropped ,...whew....lol.
CB, I don't think putting a manual fan switch would hurt...if it gives a piece of mind. But I've heard good things about "water wetter" keeping things cool..purple ice is another brand of additive for the coolant ,....
As for me ,...unless I go down there for a visit ,..i should be overheat impaired..:rofl_200:

Python Motorsports sells a kit to add the manual switch that cost me $19.95 plus $2.95 shipping. I got it off eBay but they sell it on their website also I believe. Works great. The auto function works as normal. The fan does not come on without the key being on so you won't run your battery down by accident. Just make sure wherever you install the switch there is enough room behind it. I put mine on the same plastic panel that surrounds the ignition switch. Worth the $23 just to have all the parts and instructions in one package.

FWIW I'm running a Stant thermo ( #13758 180F ) and a Borg Warner fan switch ( #TFS545 or 40-5035 ). Nothing wrong with a manual fan switch - I just like it thermally controlled - one less thing for me to look at. My fan now kicks on just above the *dot*. Had to use the original o-ring though, the BW was too thick.

I was just browsing E-bay and ran across a replacement thermoswitch that turns on at 179 degrees F. Their site says the oem switch is set for 216 degrees. That would make a difference I'm sure. Apparently it is standard equip for max's shipped to the equatorial nations. I'd give that a look.

coffee_brake said:

While the coolant was out for that nightmarish valve adjust, I put in the Napa thermostat. It fit great, and it has a much smaller spring than the stock one. The install was trouble-free, all the o-rings were in good shape and Lankee helped me remember to use lots and lots of vasoline lube. It's important. :biglaugh:

But the bike still goes to to the red on the gauge before the fan turns on. Just like it did before.

I replaced the coolant by the manual, is there a chance I missed something? Like, could there be an air bubble or something? On my Concours you have to watch that when you put the coolant in, is why I ask.

Anybody else put on a Napa thermostat? Did it change anything for you, because it's still letting my Vmax get way too hot.

Click to expand...

Is the needle going into the red or the space between where the black line ends and the red begins? If it is the space, then that is what mine has always done and I think it is normal.

I actually installed a relay for my manual fan switch. The relay turns the main fan feed on and off. My switch just has a low power + that energizes the relay. I felt this would be the safer and more reliable way since that fan takes quite a bit of current..

Good idea!

The simplest safest switch to add to the system is done by "jumping" the sending unit under the right scoop. This way you are using the factory relays and not having to run any additional power wires.

Simply take one switch and 2 sections of wire (I like to mount my switch into the plastic that surrounds the key). Run both from the switch to the sending unit (the one with 2 prongs). Leave the stock wiring in place. I use male spade connectors and push them into the factory plug from the backside just on top of the stock wires. This way the factory circuit works like normal but you can override the fan. Then when you shut the bike off the fan shuts off too and you won't end up with a dead battery because you forgot to turn the fan off (this is easier to do then you think when you have a loud bike).

If the wire falls out for any reason nothing shorts out since you aren't using the powered side of the circuit and it will still work like stock. No backfed current from using a different power source. Takes all of 20 minutes to install.

Sean

damn I never thought that the factory circuitry already used relays duh!

Ah well at least in my system I'm using both the temp switch as an automatic feature, and my manual override to turn it off when it does need cooling, eg on the highway.