Temp guage...

[shark]

Quick question, about where is normal for the temp guage to read? Mine runs about half way mark in town. The reason I ask is I noticed a "boiling" sound from the crank case after I shut it off. The coolant is full and the fan works fine. I not sure if maybe it is running on the hot side... FYI, it's a '79 GL 1000.

[virgilmobile]

My gauge will run half way and go near the top before the fan kicks in.The normal operating temp is 165-200 degrees(about).To check this I used a no-contact IR temp gauge on the head(near the intake),and radiator while running.
The gauge was from Harbor freight,about $30.I used it to find hot and cold spots in the house too.Checked the freezer temp,air conditioning,coffee temp ,etc..Pretty useful tool.

As far as the bubbling,understand first that compressed coolant should not boil until it reaches over 220 degrees or so.Also when you shut off the bike,coolant is no longer flowing past the heads.With no coolant flow,the HOT cylinder can boil the stagnant coolant at that spot IF..you are using straight water and/or the system is not building pressure(bad radiator cap).

First thing is to identify where the bubbling noise comes from.Use a 1/4" hose in the ear,like a stethoscope,to pinpoint it.Then go from there.

[shark]

I am using anti-freeze. I been riding the bike all summer... after my "carb nightmare" was resolved. I never noticed the bubbling sound until last night after a short ride. This winter I'm planning on converting it over to electronic ign. and getting rid of the points. We are planning a long trip up to the great lakes next Spring and want to make sure it is "somewhat" road worthy. Thanks for the input. jeff.

[Fred Camper]

If you have been into the coolant circuit, or if your overflow tank was empty, then it takes three long rides to purge the air from the coolant system out. So that is one possible issue. But Virgil is right that when the coolant pump stops, if the heads are hot coolant will boil for a bit. This is normal if the heads are hot.

[shark]

Thanks for the input Fred.

[mk197523]

Hello , My gauge will run half way and go near the top before the fan kicks in.The normal operating temp is 165-200 degrees.

[shark]

Thanks for the input.