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C3 thermostat leak

Bntlever

New member
Lifetime Membership
Jan 8, 2013
5
1
3
2016 KTM 450XC-F. Installed C3 thermostat with coolant heated bars and trail tech temp gauge. Works great, except for one leak. Coolant is leaking past o ring where thermostat plugs into water pump fitting. seems like I need a thicker o ring. Thanks for any thoughts, ideas. Merry Christmas
 

GKR

Well-known member
Premium Member
Nov 26, 2007
502
177
43
57
Edmonton
Never had one leak past that o-ring unless you cut it putting the thermostat in. You can use Teflon tape on the threads of the adapter going into the head but definitely not on the o-ring. Do you have it pushed into the adapter all the way? Lube the o-ring before install, make sure its seated all the way, and make sure the retaining clip is seated fully. If you nicked the o-ring you will need a new one. if you try a larger one the tstat will not seat in the adapter.
 

C3 PowerSports

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Lifetime Membership
Jan 27, 2010
109
181
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Sicamous B.C
www.c3powersports.com
2016 KTM 450XC-F. Installed C3 thermostat with coolant heated bars and trail tech temp gauge. Works great, except for one leak. Coolant is leaking past o ring where thermostat plugs into water pump fitting. seems like I need a thicker o ring. Thanks for any thoughts, ideas. Merry Christmas
I believe you are having problems getting the thermostat housing into the stainless steel mounting coupler that goes in the engine and then when you insert the thermostat housing into the coupler it is actually not going in all the way.

We have had a couple of other customers call us with this and we have found that the spec is out on the stainless coupler. We checked the couple hundred we had in stock and found a few more that we out of spec and threw them in the trash.

If anyone else is having issues and the thermostat does not go all the way in easily please contact use so we can send you a new one ASAP. info@c3powersports.com
 

C3 PowerSports

Well-known member
Lifetime Membership
Jan 27, 2010
109
181
43
Sicamous B.C
www.c3powersports.com
Never had one leak past that o-ring unless you cut it putting the thermostat in. You can use Teflon tape on the threads of the adapter going into the head but definitely not on the o-ring. Do you have it pushed into the adapter all the way? Lube the o-ring before install, make sure its seated all the way, and make sure the retaining clip is seated fully. If you nicked the o-ring you will need a new one. if you try a larger one the tstat will not seat in the adapter.
Thanks for this good reply GKR
 
M
Jan 14, 2004
3,079
1,390
113
I'm having a different problem with my bars. I'm getting an intermittent leak from under my left grip. It seems to push coolant when the thermostat is closed. This is the third season with these bars and the first two were perfect. I haven't taken anything apart yet but I'm curious, is there a plug in the end of the bars that could be leaking or is it welded.

Thx M5
 

matchrocket

Well-known member
Premium Member
Mar 2, 2016
209
69
28
Boise
I believe you are having problems getting the thermostat housing into the stainless steel mounting coupler that goes in the engine and then when you insert the thermostat housing into the coupler it is actually not going in all the way.

We have had a couple of other customers call us with this and we have found that the spec is out on the stainless coupler. We checked the couple hundred we had in stock and found a few more that we out of spec and threw them in the trash.

If anyone else is having issues and the thermostat does not go all the way in easily please contact use so we can send you a new one ASAP. info@c3powersports.com
Just installed my kit, and I have a slow drip @ where the thermostat goes into the aluminum adaptor. The clip is fully seated (Can't pull it out), but the entire ASSY is loose. I can move it side-to-side... I had a REALLY hard time getting this pushed in all the way to get the clip installed. Will send an email with details.

1669907453643.png
 
Last edited:

matchrocket

Well-known member
Premium Member
Mar 2, 2016
209
69
28
Boise
I fought a number of leaks with this kit at this point.

Eventually I had to remove all the thread tape I added and the crap it came with and used loctite on all the blinds, temp probe, and fittings for the heated bars. Both on the bars and on the tstat.

I emailed this feedback to C3.. I am now finally leak free.

I don't know if the powder coating is causing issues or if the taper is wrong or what.

Honestly for the cost this is pretty disappointing.

Now that the leaks are solved, I am happy with the product, but the amount of effort to get there at the price point isn't really acceptable in my opinion.

Sent from my Pixel 4a (5G) using Tapatalk
 
S
Nov 27, 2007
294
9
18
Kaslo,BC
Just installed my kit, and I have a slow drip @ where the thermostat goes into the aluminum adaptor. The clip is fully seated (Can't pull it out), but the entire ASSY is loose. I can move it side-to-side... I had a REALLY hard time getting this pushed in all the way to get the clip installed. Will send an email with details.

View attachment 396397
Did you get it sorted? Mine is the same….leaked after I install it…. Sealed up the threaded stainless pc again…..installed it….has a slight movement side to side…..not filling with coolant it till it’s sorted
 
S
Nov 27, 2007
294
9
18
Kaslo,BC
2016 KTM 450XC-F. Installed C3 thermostat with coolant heated bars and trail tech temp gauge. Works great, except for one leak. Coolant is leaking past o ring where thermostat plugs into water pump fitting. seems like I need a thicker o ring. Thanks for any thoughts, ideas. Merry Christmas
Did you get it sorted? Not a great design….too many places for potential leaks
 
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