Coolant bubbles-Overflow tank empty

Dear Shed Heads
84 VF1000F sheds “any” coolant in the overflow tank filled to the cold line.
Runs normal about one third warm on the Temp gage…Come to a stop at traffic and if I filled to the line will “puke” out the “extra” coolant. Bike coolant will “bubble” in frame after a ride.
Ordered a new thermostat to start.
Am I on the right trail?
If not the thermostat…head gasket?
Eric in Lempster NH USA

with a car engine it normally means head gasket or in this case gaskets :’( :frowning:

Sorry to hear the news

The good news is…this has been going on since I’ve owned it for 15,000 miles.
Like riding a gernade with the pin coming out around every 80mph corner.
Still looking for rebuild parts for my Showa MB6003 rear shock
I have Honda tech help, just need the parts…
Any help please…
Eric in Lempster NH

My VF also used to blow out water from the overflow bottle in traffic on hot days. You don’t mention the temperature when in traffic, but I assume that is high? Assuming the bike runs well and the fact that overheating in traffic is common with VF1000’s, I would suggest head gasket are not necessarily the problem .

I decided on the “fan temp switch/over ride” route and to a large extent this fixed the problem by stopping the coolant getting too hot before switching on the fans.

It’s inexpensive to do, and might be worth a try if the thermostat doesn’t fix it.

See my post some time ago,503.msg1986.html#msg1986
If the link doesn’t work type “Subaru” in the search.

All the best

Good to hear you have the had the same deal.
Temp gets well into the 3/4 range and maybe the fans kick in too late…but
my overflow tank is “always” MT. If I fill to cold, just pisses it out.
Lets face it, a switch is a lot cheaper than a head gasket after 45,000 miles.
Any help on a rear shock rebuild kit?
Lets ride on…

I am speaking as a Car Mechanic here, Can the Cooling System be pressure tested from the Radiator Cap not the expansion tank, if it can when the Bike is hot so that the coolant has expanded as much as it can, check the Pressure in the cooling System if it rises and continues to do so it is Head Gasket. You could also try a Head Gasket testing Fluid that Turns Yellow if there is any Carbon entering the Cooling System from the Combustion Chambers. Adding a Switch may solve the Problem for a while but if the Head Gasket has gone it has gone, and cause more problems and expense in the long run.