C3 heated bars - dead heading

[cbc76am]

I make my own heated bars and generally use a C3 thermostat. On my last yz450 I had the water pump seal fail form what appeared to be too much pressure when turning the bars off when they got too hot. C3 states on the website that hydrolocking the pump like that is fine.... as i'm building my next bike i'm wondering if I should try it again with a single bypass that you shut off when the bars are too hot, or make my complex dual loop setup again.

Just curious if other guys are blocking the heated bars loop and not having any issues of coolant blowing out of the weep hole on the pump.

 

[M5-]

I have home made bars on my 2011 YZ and the water pump failed, It has a dual bypass system which is always partly cracked open. I don't think the failure was related to pressure as much as it was related to engine hours. I'd have to look at the log book but it was around 130 hours or so. My 2018 YZ has the full C3 setup, which I basically never shut off completely for that reason. In the end I'm not convinced it makes any difference one way or the other, the water pumps just wear out. I should actually order a rebuild kit for my 2018 now that I think of it just to have on hand.

M5

 

[Iceland cat]

I made my own heated bars and have used them for 3 years without problem, in the beginning I was concerned with my water pump seal so I tried a loop(blue line) that goes up besides the frame and back again and it is always full flow, then there is a secondary loop(yellow line) where I can open the flow to the handlebars, note that the blue line is still and always open, yet the handlebars are quick to heat up. I also switched my plastic throttle tube for an aluminium one for quicker thermal conductivity, makes big difference

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[byeatts]

I make my own heated bars and generally use a C3 thermostat. On my last yz450 I had the water pump seal fail form what appeared to be too much pressure when turning the bars off when they got too hot. C3 states on the website that hydrolocking the pump like that is fine.... as i'm building my next bike i'm wondering if I should try it again with a single bypass that you shut off when the bars are too hot, or make my complex dual loop setup again.

Just curious if other guys are blocking the heated bars loop and not having any issues of coolant blowing out of the weep hole on the pump.

What's really needed is a diverter valve so when bars are turned off the flow redirects back to the engine inlet, I dont install the shut off valves anymore because of rider error allowing it to dead head which also causes hot spots in cylinder until T stat opens., when engine is hot the T stat is open and circulates however ewe stop for awhile and T stat closes and will dead head if rider doesn't open the bar valve. This is a flaw in the design and its pretty easy to fix using a diverter valve instead. The sport is new and this part will be mainstream soon, Its not rocket science and they already exist for other applications.

 

[Shady84]

It's a yamaha problem, I have an 18fx and the pump seal leaked before it was a snowbike. I changed the seal, it kept leaking. I changed the pump shaft and a new seal again, still leaking. But it only leaks when it's waring up in the parking lot and stops as soon as it's warm. My bar valve is always cracked open. The water pumps are not positive displacement so Deadheading isn't really what's happening. There is a bleed hole in the C3 thermostat that allows flow all the time and it's actually a surprising amount. Run a hose from the thermostat into a pail and see for yourself.

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[byeatts]

It's a yamaha problem, I have an 18fx and the pump seal leaked before it was a snowbike. I changed the seal, it kept leaking. I changed the pump shaft and a new seal again, still leaking. But it only leaks when it's waring up in the parking lot and stops as soon as it's warm. My bar valve is always cracked open. The water pumps are not positive displacement so Deadheading isn't really what's happening. There is a bleed hole in the C3 thermostat that allows flow all the time and it's actually a surprising amount. Run a hose from the thermostat into a pail and see for yourself.

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The bleed hole is very small and is not enough flow to keep even cylinder /head temps and its purpose is to bleed the air out of the system . This problem exists on all brands , The pump will cavitate without flow and is not good on any seal . We have had several failures and all due to the rider forgetting to open the valve when engine is below the T stats 170 degree threshold.

 

[00Tundra]

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It's a yamaha problem, I have an 18fx and the pump seal leaked before it was a snowbike. I changed the seal, it kept leaking. I changed the pump shaft and a new seal again, still leaking. But it only leaks when it's waring up in the parking lot and stops as soon as it's warm. My bar valve is always cracked open. The water pumps are not positive displacement so Deadheading isn't really what's happening. There is a bleed hole in the C3 thermostat that allows flow all the time and it's actually a surprising amount. Run a hose from the thermostat into a pail and see for yourself.

Sent from my SM-G991W using Tapatalk

I have the same bike(18 YZ450FX) and the water pump has always leaked when cold. It did this in stock form no heated bars. I have replaced seals 3 or 4 times . During the summer it does not leak at all. Drop those temps below 40deg f though and it will leak until the motor warms up. It is a Yamaha issue. Evan changed to a Boysen pump. I believe it is the material that the seals are made of get hard when cold.

 

[eric82930]

For reference the Polaris dragons and pros had no bypass on the tstat. it just dead head until it opened. But the stat was literally in the head so it would open well before things got to hot in the cyl.

 

[Shady84]

The bleed hole is very small and is not enough flow to keep even cylinder /head temps and its purpose is to bleed the air out of the system . This problem exists on all brands , The pump will cavitate without flow and is not good on any seal . We have had several failures and all due to the rider forgetting to open the valve when engine is below the T stats 170 degree threshold.

Do you have some pictures of the cavitation? I've looked and can't see any evidence of it on mine.

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[cbc76am]

Well that is enough go around for me to go with a dual value system, unless I can find a diverter value that will work. Thank you guys, confirmation that it is common is enough of a reason for me to plumb up the overly complex setup once again.

 

[cbc76am]

this will do it for me: https://www.mcmaster.com/three-way-ball-valves/panel-mount-threaded-diverting-valves/

I don't use that push to fit crap, and run npt barb to silicone hose - so this valve will be the solution I need, good chat as always byeatts

 

[daloof]

I too was concerned about this when i first converted over to coolant heated C3 bars..... so i looked it up and this info is on their website...

________________________________________________

link:

Heated Bars + Thermostat Bundle!

Heated handlebars and thermostats go hand in hand. Thermostat keeps your engine warm and our coolant heated CenterFlow handlebars keep your hands warm.

c3powersports.com

then click on Bars FAQ tab.


Copied from their website:
I heard it's bad to dead-head the bike's water pump?

Where did you hear that???

4 things:

1. A C3 thermostat + bars setup can never be deadheaded. Our thermostats are built to our custom specifications with a small bleed hole, so there is a built-in bypass system at all times.
2. Even if you could, "dead-heading the pump" is not a swear word or even a bad thing at all. Ask anyone who's worked in industry - it's a very common and very widely used method to throttle centrifugal pump flow and control complex systems.
   1. The reason that you may have heard as a warning against deadheading pumps is if the same liquid is churned around in the same space for an extended period of time (typically hours and hours straight), the friction will eventually build up enough heat to straight-up vaporize the fluid ("cavitation"), and those pockets of gas are indeed bad for the impeller and bearings. There are some applications where this is a legitimate concern, but clearly that's not the case in a motorcycle engine scenario where any liquid friction heat is negligible (to say the least) compared to the internal combustion occurring in the cylinder inches away! And it is ESPECIALLY not a concern in a system where the thermostat itself inherently acts as a safety control valve, sending up to 100% of coolant flow through the radiators if the coolant temp gets even remotely close to boil point. So all good! At least when you're talking centrifugal pumps like on bikes ("positive displacement" type pumps, that's a different story)
3. If for some reason you are still concerned, with the valve conveniently located directly ON THE HANDLEBARS with all your other controls, you will have no problem maintaining a perfect level of warmth on the fly without ever closing it entirely, if that is what you choose!
4. If for some reason you are still scared or apprehensive, we will add the fittings for you to elegantly plumb in another bypass circuit to your next order for free.

What about "hot spots"?

See above about A) the optimized "bleed hole" ensuring the proper slow circulation (never stagnant), and B) the cylinder of course heats up all coolant uniformly - definitely don't worry about "hot spots" in C3 systems.

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anyhow, ill always leave the valve slightly open anyways.... ?‍