Weird overheating issue

[guatemalaman]

Got a 1999 Royal Star Venture. I've asked this question before but it's happening again.

 

Changed the fluids and burped did this overnight and two or three different times added a little bit of fluid but not much maybe two cups

 

Start of day ,  idled for 20 minutes fan came on never got radiator red light

 

Then  Road for 45 minutes highway speed as well and stop and go through a small town ...no red light. Turned around and headed back.  

 

Rode another 20 minutes at highway speed went to a stoplight... red light comes on. Turned around then ... at highway speed after 3 or 4 minutes red light goes off.

 

Got home  slowing down in the housing addition.  red light comes on again and stays on when I get home

 

 

This same scenario happened to me last week when I went for a 2-hour ride one way it's like an increasing heat and then once it got up there... the temp,  the red light would go on...if slowing or stopped ...and off... if I increase the speed and cruise

 

Final thought for the first hour and a half I rode the bike starting to stop highway speeds everything's fine no red light then after like an hour and a half I get into the same situation that before no red light but now I get red lights constantly it's like it's building heat over time I'm thinking of stuck three quarter open thermostat maybe I don't know

 

Any further ideas thank you.

[Freebird]

I. honestly. don't know. but I. think I would start with a new thermostat.  

[BlueSky]

Maybe verify the radiator temperature with an infrared thermometer if it isn't boiling over.  

 

[Marcarl]

Might be the bypass valve if there is one.

[KB2RWW]

I have what seams to be the same problem with my 1999 RSV. Light coming on for a while but it’s not boiling over. Changed flued and burped air thinking it’s the problem. Fan is working. Thinking it’s ether time to check valve clearance due to never been performed since I got the bike, change thermostat, pull and test sensor or see if water pump impeller has gone bad.

[bpate4home]

4 hours ago, KB2RWW said:

I have what seams to be the same problem with my 1999 RSV. Light coming on for a while but it’s not boiling over. Changed flued and burped air thinking it’s the problem. Fan is working. Thinking it’s ether time to check valve clearance due to never been performed since I got the bike, change thermostat, pull and test sensor or see if water pump impeller has gone bad.

On my '06 I had something similar to this.  Drove me nuts for about 6 months.  Then one day I would see the fan on and then it would shut off pretty quick.  I replaced the fuse and the problem went away.  I don't know why but it did.