2016 pro power loss after overheat

[braaapbraaap]

Sooo I have a 2016 pro 800 163 with silber turbo 7# boost half av gas half 91. 1500km and was running mint... then I blew a coolant hose and got her real toasty. 115C when I looked at gauge before shutting down on its own. Seen coolant had drained then towed to truck. Patched hose, refilled and tried riding a few days later. Now I’m experiencing terrible lag, and rpms dropped from 8500 WOT to around 8100rpm. The sled ran very slobbery before, plugs would be wet and exhaust smoked a lot. Now the plugs and exhaust look real lean, but sled isn’t detonating or anything. Idle rpm is same as before 1700rpm. Compression same as before 110 per side. Starts idles and reverse fine. Not burning or leaking coolant. Changed exhaust springs and donuts. Pressure tested exhaust, intake and crank case (no leaks). Checked turbo impeller, turbine and shaft (ok), disassembled and inspected blow off valve and aneroid valve (ok). Changed plugs as well.
Was running 74g weights and switched to 68s and only gained about 150rpm and didn’t help nasty slow lag. Seemed to sometimes stall out for a moment around 6500rpm when under good load. This made be think exhaust valves, cleaned and inspected exhaust valves but made no difference.
Rode the sled 3 more days like this with out any changes to performance or compression.
Anybody have any thoughts on what else I can check that could do this after a over heat? Ill be checking tps and probably replacing the head seals either way, but any other ideas would be greatly appreciated.

 

[TRS]

Did the anti freeze cover/drench everything under the hood?

 

[braaapbraaap]

Nope. Lower coolant hose drained through bottom panel. Now the coolant doesn’t leak and stays at the proper level.

 

[willjogervais]

I would do a leakdown test just to verify you didn't scorch a piston. That is very hot...

 

[2XM3]

yup leakdown, rings,pistons, head,
one has a issue

 

[braaapbraaap]

Completed cylinder leak down test and crankcase leak test. Cylinder test results compared to another axys and were all the same. Don’t think my issue is cylinder or compression related..... still no idea..

 

[509_Colton]

Do the test hot or cold? Could have lost temper in the rings

 

[braaapbraaap]

I tested hot and cold... but I was also leaning towards a ring issue.... maybe sticking once the engines actually running.... gonna pull the top end apart when ever I get some free time over the next week or 2 and have a good look. Will update when I know more ??

 

[willjogervais]

Good luck figuring it out!

 

[braaapbraaap]

Cylinders and pistons look like new. Both top cylinder orings had a bad area which may have just been leaking under boost. Didn’t leak when pressure testing crankcase. Will reseal and retest.... hopefully this season.

 

[braaapbraaap]

Forgot to update after I retested a few months ago.... resealed top end and went through clutches again. Still had major power loss. I’m gonna try swapping turbos with my buddy when we get a chance. If that don’t work I’ll just change rings. Will update again eventually.

 

[Sheetmetalfab]

Wonder if the lack of cooling scorched the turbo bearings?

 

[Teth-Air]

If it is running leaner now than before it is either getting more air or less fuel. This is not what I would expect with a compression loss. It is something fuel or sensor related. Maybe your exhaust temperature sensor got fried and the ECU thinks the engine is needs less fuel now? A bad reed will also cause it to bog but likely you would have noticed a difference per side when you had the head off.