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Look for tiny bubbles in the coolant recovery bottle while running and normal temp or hot. Mine never got coolant in the oil but looked like Alka Seltzer in the recovery bottle.

Couple of other thoughts... A head gasket can fail to the oil passages, to the coolant system, or to the outside air. Are you getting excessive crank case blow by? Is there any external compression leakage? Are you getting combustion gases in the coolant system? Cap off coolant system shouldn't be expelling gases or pressure. Has the coolant level dropped or increased? Does the coolant appear to be contaminated in any way? (Oily, brownish tinge etc.) Just a few things that came to mind. Good luck.

I can't mark any comment as the answer because both members that helped me diagnose this beast has provided the correct information to diagnose the issue. Thanks to both Alien10 and Joe Breaux for the help. With the information both provided I'm 100% sure there is a blown head gasket. The breach of gasket material seems to be between the coolant channel and the combustion chamber. Now all that remains is do I down the machine myself or take to shop. That is going to depend if I can get an enclosed place to work on this beast. LOL Thanks guys I appreciate the help.

I have a 2017 Massimo 500 that is locked in 4 wheel drive don’t know if the switch is working or if it’s something else does it have a fuse for the switch

A little pressure in the radiator after sitting a few days would seem to preclude a head gasket failure between the combustion chamber and the coolant jackets. Pressure would push coolant into the cylinder or if failed between oil and coolant, into the crank case. Also when running, a head gasket blown into the cooling system will certainly provide pressure into the cooling system and exiting at the open radiator fill. There is a tester that will analyze the coolant to see if combustion products are contaminating it. Not sure if you can borrow one of these from a local auto parts store or not. There used to be a radiator air pump that you'd use in place of the radiator cap. Pump up pressure in the cooling system and watch the pressure gauge to see if it holds or bleeds off. In your video, the bubbles are somewhat consistent in volume over the course of the video with the engine idling. What happens if you raise the RPMs while watching the coolant in the radiator? Do the bubbles increase in volume as you would expect if it is coming from a head gasket leak into the cooling system. This is more of a guess on what you've found so far, but maybe there is still a big air bubble somewhere in the cooling system that is slowly percolating up as the pump is pumping the coolant.

I'm gonna say that a "stuck float" is the best possible answer. The pressure from the gravity feed was likely enough to push open the float valve.

Compression test clarification question. Did you get 120lbs that then bled down to 105 in 15 minutes of sitting? Or did you do a second test 15 minutes later and only got 105lbs. Remember, rings and pistons are not complete seals, they all naturally leak. Max compression is only required to be present during the power stroke, and for a fraction of a second. If there's no coolant in the oil, what else has convinced you of a failed head gasket? You might consider additional testing before tearing into the engine.

Been there..I had to pay to get it done because I had just had back surgery. Did not appear to be to difficult but after replacing gasket we realized the head was cracked..better check yours while it's off. This is a common issue on Hisun engine.I honestly think they don't torque the head bolts during assembly. None of mine were .good luck