2016 viper turbo overheating when in boost

[zx4ever]

So I purchased a 2016 viper turbo this summer off a guy. I have not had any good luck with it so far. First ride out it Vapor locked on me and took some time to start. Had to pressure the tank up to get it to go. So I added heat shield and venting to the side panel and fuel line covers to keep the heat down and seemed to work, but could have been the outside temp was cold the 2nd time out. But now the sled is running super hot and going into limp mode on climbs. In a foot of fresh at about 12 lbs of boost. The old owners said the sled had the boost it kit with Carrillo rods and low compression pistons. While I was inspecting I noticed and measured it has a .66 head shim. So that makes me wonder if it also has low compression pistons? All my reading on here points to head shim leak. So I did a leak down test on the cylinders and it was 2% on 2 of them and 3% on the other. I also did a compression test and they were all 170 lb which I’m not sure is in range with the head shim and pistons or just headshim. Anyone have any numbers of what they have with just head shim? While I was doing a leak down test there was no air bubbles in coolant and colour of coolant is good. Could a major air lock cause these problems under boost? As on the trail in low snow conditions the temps are good and the fan kicks on and cools it off. Any other ideas on what I should test before I tear into this motor?

 

[zx4ever]

Also here is a picture and specs of what it has on it.

 

[zx4ever]

Picture of it

 

[zx4ever]

So I did a block test and fluid stayed blue. So maybe it’s just a coolant airlock hopefully vacuum fill tonight and test again

 

[mbarryracing]

Extra HP produces extra heat that is taxing on a stock cooling system sized for stock HP levels.
Does that sled have extra add-on heat exchangers / coolers in the tunnel?

 

[Norse]

You need over half a tank og fuel for steep climbs or it starts to stutter and shoot, and maybe overfill oil tank or you could run into issues. If you're in deep powder then normally it shouldn't overheat even without extra tunnel cooler. Worth a thought..

 

[Norse]

Maybe head gasket? Not sure if you can see that on a pressure test. Or maybe thermostat.

 

[zx4ever]

Extra HP produces extra heat that is taxing on a stock cooling system sized for stock HP levels.
Does that sled have extra add-on heat exchangers / coolers in the tunnel?

No just the stock front heat exchanger and rad and fan.

 

[zx4ever]

Thanks for the replies guys. I think I hit it figured. I did a leak down test and it was 2%in 2 cylinders and 3%in the other. I also drained and vacuum filled the coolant system and I believe there was an airlock in there. As when I tested it in the mountains at the same location and conditions it did not overheat. Seams good to go. This thing is an animal.