Mark,
Yes, you are likely boiling off the overfill of the system. About 10mm over the core is correct.
The less antifreeze in the mix, the better heat transfer BUT lower boil point. 60/40 water/coolant is a good mix, or just use a premixed coolant like engine ice. Don't use automotive coolants(Toyota coolant is OK) as they usually contain abrasives for cleaning the cooling systems during long term use. Just drain, flush with water, and refill.
For 4-strokes with boil over problems in tight woods we have run the EVANS waterless coolant with great results in several bikes. Its the only stuff I'd put in a new 4-stroke.
|