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My Overheating problem is back!

Athosch97

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Hello everyone! Unfortunately my overheating problem is back and this time it's really weird.. Somehow when the bike is stationary and in traffic my temperatures are close to normal, only reaching 102 celsius, however today when I got into highway,
the bike reached 110 celsius, it dropped after that but maintained temperature at 105 celsius which in my opinion that is really warm for a highway. I changed my coolant just this morning because I suspected it before taking it for a ride, EngineICE is what
I'm using which I believe that's what everyone suggests. Any ideas? P.S. I changed my exhaust which I don't think that matters but it's worth mentioning, My exhaust is now to the side instead of the back like the factory. Any help is appreciated! I am waiting for the bike to cool down and flush it with some water and let it work for some time to see how it goes.
 

What have you done (fully) in the past to fix it?

.
I did a very thorough radiator clean, took it off let it in vinegar for 2 days i changed all the hoses got new ones when i put on the radiator, flushed it and it worked like a charm. Bike was perfect for so much time! Even now when I don't go into highways it won't overheat it runs very cool. I will get myself a new radiator cap just in case that's the problem, if not thermostat, then water pump. If none of that works i guess im busted ahaha might be compression from the head going into the radiator??
 
A head gasket failure is rarely one-way. If your head gasket had failed the oil in your engine would have a milky consistency to it and the coolant would also be contaminated.
Honestly Gary! That is music to my ears, changed the oil 2 days ago and it was clean! I really hope I can get away with a radiator cap! Also noticed that mine is changed, so the previous owner must've changed it too. Thankyou for the fast reply! Hope I get her running perfect soon, haven't ridden in weeks I've been working 7/7
 
In order for efficient heat transfer from the engine to the coolant the engine water jacket must also be clean.
There are reasons there might not be good transfer. Things to check are coolant characteristics/properties. The thermostat may be open enough at lower rpm but not open enough at higher rpm where more heat is being created by the motor. Same thing with the water pump impeller. Is the impeller efficient enough to produce higher volume movement of coolant at higher rpm?
Also we had a member who also had an overheating problem with his Daytona 675. Turns out some one who had the bike disassembled spilled oil on the radiator and when the bike was reassembled and he road it overheating started increasing as days of riding increased. When I inspected the radiator I could not see light through the cooling fins. The oil created and perfect medium for collecting dirt/dust as the air flowed and eventually cause very little air to flow per the volume of cooling needed at highway speeds. We used dish soap to wash the oil and dirt out and it was the bee's knees.
 
The T stat is located on the rear of the cylinder, accessible from the port side.

It can be removed W/O removing the throttle bodies(as stated in the manual).

It is in a tight spot but do-able.

I changed mine about a year ago and some ding dong (from the factory as I knew the original owner)
RED loctited the housing bolts into the block... I could only get heat to one area, the other side just back and forth, back and forth.

My T stat was fine... Just the change in seasons showed a difference in temps...
 
Thankyou all for the replies, I am changing the radiator cap today, if that doesn't work im going straight for the thermostat, I hope I won't have to go further than that.
 
Hello again everyone, Just ordered the thermostat but I need help understanding something, Say my thermostat doesn't work. Wouldn't the temperature rise while the bike is also stationary? Why does it pop up only in highway after 140kmh? (Excuse my questions I don't know if they're dumb or not just trying to understand everything going on and this Head Gasket fail chance has made me SO paranoid..)
 
I'd think the engine is making more heat at more RPMs.

If the stat isn't opening fully/restricted, heat would eventually rise as you don't have enough water flow
at higher speeds.

.
Yep it makes sense, I also read again what Motogiro said which he actually explains it. Hope thermostat is the issue. Thanks all again!
 
Hey mate I've been having the same issues with my bike, the fan doesn't seem to bring my temps down and the fan constantly comes on at highway speeds and holds around 101 celcius. Have you had any progress with your issue? I've done about 5 coolant flushes but to no avail. My radiator fins looks fine from the outside but i suspect it's clogged internally.
 
Hey mate I've been having the same issues with my bike, the fan doesn't seem to bring my temps down and the fan constantly comes on at highway speeds and holds around 101 celcius. Have you had any progress with your issue? I've done about 5 coolant flushes but to no avail. My radiator fins looks fine from the outside but i suspect it's clogged internally.
Hey there @hun7ter ! Unfortunately no progress, also did alot of flushes, took a loot at the thermostat doesn't look too good, ordered a new thermostat and a radiator but where I live delivery takes ages, I might get the parts in a month or so, and I ordered everything 15 days ago. I bet you're also hoping it's not a head gasket failure too.. let me know if you have any updates aswell, I will try flushing it with a motul cleaner someone suggested I will let you know of any updates.
 
Hey there @hun7ter ! Unfortunately no progress, also did alot of flushes, took a loot at the thermostat doesn't look too good, ordered a new thermostat and a radiator but where I live delivery takes ages, I might get the parts in a month or so, and I ordered everything 15 days ago. I bet you're also hoping it's not a head gasket failure too.. let me know if you have any updates aswell, I will try flushing it with a motul cleaner someone suggested I will let you know of any updates.
Yeah mate initially i was worried it was a HG failure, but after tons of research I'm pretty sure it isn't. Fz6's are not known for blowing their HG. Also a quick way to test is to get your bike up to operating temp with the radiator cap off. If you notice bubbling at the top of the radiator then it's likely a HG failure. Also after some research, I've seen that radiator cleaners don't do much. I'm hoping a new radiator will solve my problems. I'll keep you posted on my progress. Cheers buddy.
 
Yeah mate initially i was worried it was a HG failure, but after tons of research I'm pretty sure it isn't. Fz6's are not known for blowing their HG. Also a quick way to test is to get your bike up to operating temp with the radiator cap off. If you notice bubbling at the top of the radiator then it's likely a HG failure. Also after some research, I've seen that radiator cleaners don't do much. I'm hoping a new radiator will solve my problems. I'll keep you posted on my progress. Cheers buddy.
Hmm, all I did was check the oil if it was milky didn't really do what you tried, once I head home from work I'll try that hopefully no bubbling, kind of stressed to be honest because when I was "bleeding" the bubbles out of the radiator when I flushed it it was bubbling a bit, hopefully that was leftover flusher.
 
Hmm, all I did was check the oil if it was milky didn't really do what you tried, once I head home from work I'll try that hopefully no bubbling, kind of stressed to be honest because when I was "bleeding" the bubbles out of the radiator when I flushed it it was bubbling a bit, hopefully that was leftover flusher.
I highly doubt it's the HG mate. Mine does have random small bubbles when i rev it hard with the radiator cap off probably from the liquid sloshing around in the rad. HG won't just perish like that, unless you overheated it really badly. If the max temp you've hit is 110, that's still within the safe limit of the fz6 engine. Just curious when you were cruising and your temps were above 100, was your fan running?
 
The bike went to 113, didn't get the temp sign on the dash but I still stopped and wait for it to cool. Unfortunately I did the same test you did, I won't lie, it looks bad for me I think I'm screwed, would love an opinion from someone who knows better.

 
I highly doubt it's the HG mate. Mine does have random small bubbles when i rev it hard with the radiator cap off probably from the liquid sloshing around in the rad. HG won't just perish like that, unless you overheated it really badly. If the max temp you've hit is 110, that's still within the safe limit of the fz6 engine. Just curious when you were cruising and your temps were above 100, was your fan running?
Yes, fan is kicking in normally, no matter what the temperature rises when I speed up, when I cruise normally around 100-110kmh bike stays at 100-102C
 
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