Troubleshooting overheating problem

[knee deep in it]

took my 04 ProX 700 VES out for a ride a week ago. A buddy was riding it and he kept the throttle at a constant position (newbie) on the trail up to the cabin. When we stopped, there was steam coming from the hood and coolant on the engine bay. There was also a bunch of coolant on the trail.

The cap may have not been on correctly. I don't recall but it is zip tied to the steering post and that nterfered witht he closing. I have moved it and that is no longer an issue. The cap is on correctly now.

Didn't ride it much that day because I was worried about overheating it again. Filled it with water and rode it back to the staging area (10 km ). It didn't overheat and didn't lose any coolant.
How do I proceed? I have to change coolant because it is too thinly mixed now (too much water). Should I fire up the sled and wait for it to overheat to ensure no coolant leaks? Can I just drain about 1/3 and add enough coolant to get it to the 50/50 mixture?

Any tips to ensure no air bubbles in the line? Any other advice?

 

[snojunkee]

I definitely would not try to overheat again.test it with a cooling system pressure tester(any garage has one)then loosen the bottom hose to allow enough coolant to escape & add antifreeze.test this with a coolant tester so that it is safe for cold temps,u'll have to start the machine and let coolant circulate,set the front of the machine higher than the rear ,this allows for air to escape the haet exchangers.feel these to see if coolant is circulating,they will b warm if yes,cold if no.