overheating

Hi
my safari with 2.25 petrol overheats, doesnt quite boil but is very bothered.
new rad, replaced waterpump 4 months ago. First happened a month ago, thought a stuck thermostsat was problem. replaced with 89 degree t'stat on saturday, and now doesn't boil but runs so hot the heater works.
but this is a cruel irony when the weather is hot......
ideas?
runs Ok, idles a bit fast, but occasional bang from exhaust on overrun.
ideas?

bypass housing has a large hole on most ,restricting hole by tin gasket with 1/2 hole helps push more coolant through rad

I always thought series landrover thermostats where 74 or 82 degrees?

The occasional bang on over-run could be either you have been running rich and have a carbon build-up, so check your plugs.

You could also be running a little bit too advanced, so check your ignition timing and that the dizzy is working as it should.

I agree with Blackburn, you should have at most an 82deg thermostat. probably with a small bypass hole in it.

You possibly need to flush the block with some proprietory agents as well as the water jacket could be clogging up with lots of crud from over the years reducing the heat exchange surface.

Mine had the same a few days ago.
Blown gasket -former owner did put a copper one inn- between 1st and 2nd cilinder.
That brings me to an old discussion here; If you have an engine with
8:1 ratio, never use a copper one! It simply can't handle the stress.

I thought popping on overrun was too far retarded...i.e. vac advance not working when throttle completely closed.

I had a lot of overheating problems last year - I hadn't noticed that the PO had blocked the rad grill with a piece of corrugated plastic - good in winter, not in summer...

sometimes it's a daft problem, like no airflow to the rad!

Overheating has always been a problem when pushing de engine to its limits. Our militairy landies were all equipped with an oilcooler and better vents to prevent overheating.