I have also faced lot of problems in overheating my M-800 (MPFI).
1. In Pune (05-04-2014) - Temperature Needle raised to H and coolant was thrown out of radiator.
a) With help of local mechanic, checked all the hose which were all right.
b) Thermostat was removed, as per him it is not needed in our climatic condition and coolant will get free flow after removing it.
c) Radiator choke-up removed (If any) and all springs were removed from radiator for free flow (Laxmi Radiator Works - Pune).
(06-04-2014) Vehicle was driven back to Nasik successfully without any overheating problems.
2. In Nasik (26-04-2014) - Same incident as in Pune on 05-04-2014.
a) Checked with Laukik's Motor Care, after giving history of such problem and work done in Pune, the mechanic investigated and came to conclusion that the Head Gasket is blown and must be replaced and advised not to run the car.
b) Immediately asked them to get it replaced.
c) Head was machined and cleared all pores on it.
d) Elbow and all Hoses were replaced.
e) Head Gasket was replaced with all the packing covers (MGP).
f) Time Belt Replaced (MGP)
g) Coolant replaced.
After a long test-drive, it was found that car is not over heating and coolant level is maintained. It seems that my overheating problem is solved.
Surprisingly, It has come to my knowledge that in MPFI Engine the Head Gasket Fitment is of Carb model.
Please go through above and reply your valuable suggestions for the work done.
Thanks & Regards,