Troybilt pressure washer stopped running, won't restart, pulls HARD

I bought a troybuilt pressure washer several years ago that has a B&S 175cc motor 11P902-0127-B1.  It is supposed to put out 2700psi @ 2.3 GPM.  It has maybe 90 hours on it.  It worked fine for the first 89 hours.
 
Yesterday it sped up a few hundred RPM and ran unevenly for a few seconds, so I shut it off.  I could see nothing wrong, so I restarted it and it ran fine for half a minute or so, then it just shut down as if the I/O switch had been moved to O.
 
After checking some more, when I pulled on the starter cord, it spun over as if there were no compression at all,... like the spark plug had been taken out, or a valve was stuck open.  The spark plug is clean.
 
This morning when I tried again, it acted as if it had 28:1 compression.  It felt like I was trying to start a diesel motor.  Very difficult to pull through.
 
It has a spark, and half a tank of gas. The oil level is good.  The airfilter is clean.
 
Before I try to start it, I always make sure the hoses are hooked up, the water is on, and the hoses have been purged of air by squeezing the trigger in the handle letting gardenhose pressure push water through the hoses for a minute or so.
 
Got any ideas?

AVB
First diesels are rarely have more 18:1 compression ratios; usually around 15-16:1.
 
Without compression test you don't actually know the amount of compression. But before check that pull the valve cover and verify that the push rods are even still in the rocker arms.
 
To be it sounds the governor/oil slinger failed first and if a push fell down inside to may have took out the camshaft gears or worse. Either it sounds your in for a engine tear down to find what failed and to see if damage is too bad. If the govenor/oil slinger failed there is a good chance of aluminum transfer from the connecting rod to the crankshaft journal can cause extreme fiction causing what might seem extreme compression.
 
Just be aware that repairs can easily exceed to cost of a replacement pressure washer as this a vertical mount setup.

I was exaggerating just to make a point when I mentioned the 28:1.  The compression is obviously way more than the original 8:1 or whatever.  You are right, I don't know what the actual compression is, although I do have a compression tester somewhere in a box in the workshop.  I don't really care what the compression is in absolute terms, ... I just know it is waaaaaayyyyy more than normal.
 
Thanks, I'll pull the valve cover and see what I can see about pushrods and rocker arms.

From the youtube videos, it appears replacing the ACR requires major disassembly.
 
Curiously, when I took the valve cover off, the valves appear to have a few thousands clearance on the intake, and no clearance on the exhaust.  The exhaust rocker arm never did get loose as the engine was pulled through.

I set the valves. Pretty simple job.  They are working normally it appears,.. both closed during compression stroke, exh valve open just prior to TDC, etc.
 
Looks like an ACR issue.  I could replace it myself, but I'm not entertained with that kind of thing anymore.  What would a typical shop charge to replace/repair it, assuming there are no loose bits and pieces in the crankcase that have "schrapnelled" the insides of the thing?
 
I'm afraid it would be more than the whole pressure washer is worth.