1987 Honda 600F Hurricane, just got carb cleaned, new fork seals, new brakes done....

When I left the repair shop, test rode it around the neighborhood, runs great like new! But... When I hit the highway going 50+ mph, my Thermostat needle jumped from near the C right over to the border line of the H,

When I finally got home, checked for any leaks, there were none, but can smell some antifreeze and very little smoke came from the bike.

Does anyone have any suggestions?

 

Well Im really new to the motorcycle world so I cant tell you for sure, but knowing things about cars, I would say you have a leak. If you can smell antifreeze its coming out somewhere. If your 100% sure its not a leak, make sure the thermostat works properly. If it's neither of those, I would take it in and have it checked out. Better to be safe than to have to buy a new engine cause you over-heated and blew yours.

 

If you have or know someone who has a temp gun shoot the engine to see what the temp is. If its under 180 or close to that after running your guage or sending unit could be bad. Im not a bike tech but know how guages work and if it was overheating the guage would climb at a slow steady rate and it should happen after minutes of idling also. Smelling antifreeze is not good though.

 

I "burped" the cooling system, I took the radiator cap off, drained the coolant system and a reddish pink substance came out, (not coolant color), must of been old coolant, wonder why it's reddish? anyways, hit the throttle to 4-5 rpms 4-5 times and refilled coolant at the radiator cap and put back radiator cap, took it for a ride and instead of heating to the "H" in 5 minutes, it took me about 10 minutes. I've been told to check the Thermostat, any other suggestions on what it could be?

Thanks.

 

Is there enough air getting to the engine? Other than that I cant think of anything.

So overall here are the things I can think of:
1. Leak
2. Bad thermostat
3. Engine is actually overhearting

 

you know, my temp gauge normally reads right above the C, when i took a ride out of town the other day, once i would hit 70+ the needle started jumping from C - H and back down very very rapdily. i am sure this was just a malfuncion, one thing i did notice was there is a terminal connector that connects from the radiator, lower left corner sitting on the bike. mine had come off, i have not had a chance to check this to see if that is what was causing my problem or not since i cant ride my bike right now, but thought maybe you want to check something like that.

 

Yeah I had a good idea for checking for leaks last night when I opened up the bike and drained the cooling system, Question: If it is the Thermostat - what exactly am I looking for? and if I need to replace it do I need a special one for my 1987 Honda CBR600f Hurricane?

Appreciate all your advice

 

Do bikes have water pumps? I'm pretty sure when a car does that its the pump, (tyhe wild temps), mine goes fron just above c then to about 1/2 then once I start to ride it goes back to just above c. Also while were on the subject, in my dirt I use this specialized coolent, can you do the same on sport bikes?

 

dont know about the coolant, but yes bikes have water pumps too. and when i put that tab back on my radiator, my temp gauge stopped jumping.

 

Ok, I "burped" the system by draining the old coolant fully and revving the throttle 4-5 times w/o any coolant in it, then filled it w/ 50/50 coolant like it said in the manual, and in the manual, it just says to check the thermostat, so I opened up the bike again and I have the thermostat, but I have no clue what to look for, can anyone help with this?

Thanks