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Black art of keeping the Bird cool


Tom

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Hey folks, first post worst post, bike troubles :) brief introduction, started riding 2 years ago by getting myself the Bird since I always like that specific bike when I was a kid, made quite some miles on it, made my first stoppie, wheelie, traveled around and became even more of a fan of this turbine smooth easy going machine.

 

The only thing that bothered me was cooling. I know it's not the ideal bike for the city, but at times it would get to that dreadful above 120'C zone so for this year's service I gave my mechanic the new rad (aluminum ebay thing) and OEM rad cap, cap gasket and thermoswitch. He assessed that the rad cap and switch were ok so he didn't change them, they're in my parts box. 

 

I have no hands on mechanical experience nor the means to learn, I live near the city center, so giving the bike to the mechanic is my only option. I don't know if this mechanic is sloppy, but he has a good reputation (Honda bikes mainly, owned a Bird 10 years ago etc). But the bike doesn't cool good enough. For example I expected that the cruising temp. would drop a few 'C on the new aluminum rad, that didn't happen, still 84'C. City scooting was as usual, quick to go into 100'C+ and there were few instances when it would go into 110+. 

 

Also, I noticed a pattern, not sure if this means anything but on the days when I would ride open roads, cooling was a complete non issue, temps all low and normal. But if I made the bike go into 104'C and more, it would have a hard time coming down, and it would often have some sporadic fan operation, sometimes I would hear it coming on at those temps, sometimes not. Without blaming the mechanic, how the hell is this happening on the "new system", with new rad and all. Is it possible that the bike is tough to burp? Or could it be the faulty fan, since the mechanic mention something about the fan needing the replacement on my next service.

 

Today the bike went into 110'C in the city, I pulled to the side and after half a minute water started to leak from above the bike stand. How do I fix this, or better yet, what the heck do I tell my mechanic to do this time? 

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I’ve had cooling issues.

 

The XX runs hot.  Fan kicks in shortly before reaching H.  If your bike is reaching boil over before the fan kicks in, you may have air in the system, a failed thermostat, or both.  If your bike gets close to H and the fan cycles on and off, that’s normal.

 

I wired a bypass switch for the fan years ago.  When I went to Evans coolant and a new thermostat, everything worked fine.  Now my fan doesn’t come on without the bypass switch.  I can’t imagine the switch decided now to fail, but the circuit is otherwise good.  An easy test of the fan motor is to ground the sensor wire going to the switch.  If the fan runs constantly when connected to a good ground, the fan is fine.

 

It could just be a matter of a twitchy ground connection preventing the fan from working as it should.

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Is there a chance that the coolant dripping is a sign of something catastrophic (gasket etc?) and also, theoretically is the bike good to ride now if I drive it on open road where fan doesn't have to come in?

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The gauge is showing you the coolant temp at the engine, the fan switch is seeing the coolant temp at the 'cold' side of the radiator.  Because of that, seeing temps that don't exactly jive with the fan operation is normal.  I'm too lazy to do the exact conversions to Farenheit, but your numbers seem ok.  And yes, totally normal to see consistently lower temps cruising the highway vs. slow riding.  Mine will cruise at under 190F on the highway and will go over 220F in traffic, they all do unless modified.  Some people think they just have to modify it to save it from killing itself, but it won't.  Get used to seeing the high numbers and know that it's normal.  If you want to see lower city temps add a second fan and/or install a manual switch to run the fan so it doesn't wait for the high temps to hit.  You could also install a different temp sensor to do it automatically.

 

Coolant dripping is not normal.  It could just be that the mechanic over filled it and it's purging the excess from the coolant overflow bottle, or you have a leak.  You'll have to track down where it's coming from to know.  Did you replace the radiator because yours was damaged or were you just seeking lower temps?  I'd trust an old Honda rad. more than a new China rad, just assuming that "eBay radiator" means it's Chinessium.  I've seen some of the fancy all aluminum Chinese radiators cause overheating in cars and a cheap Chinese 'normal' replacement one cured them.

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50 minutes ago, superhawk996 said:

Mine will cruise at under 190F on the highway and will go over 220F in traffic

Just so others know, 220F = 104.4C and the 110C he is speaking of = 230F.  If things get hot enough, it will punk out more than the overflow bottle will hold being that it is part way filled when cold.

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My 97 runs stone cold. Even when it's over 95f + and humid, in stop and go traffic, its never overheated. Get an infrared temp gun to check the rad, cylinder head, cylinders, and water pump when its running to cross check the gauge. The sensor that trips the fans to cycle should be verified as well as the fans themselves. Inspect the radiator to make sure that the cooling fins aren't damaged or plugged with debree or insects. I installed a new Yosh system on mine the year before last and took the time to give the rad attention while I was in there working.

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4 hours ago, superhawk996 said:

The gauge is showing you the coolant temp at the engine, the fan switch is seeing the coolant temp at the 'cold' side of the radiator.  Because of that, seeing temps that don't exactly jive with the fan operation is normal.  I'm too lazy to do the exact conversions to Farenheit, but your numbers seem ok.  And yes, totally normal to see consistently lower temps cruising the highway vs. slow riding.  Mine will cruise at under 190F on the highway and will go over 220F in traffic, they all do unless modified.  Some people think they just have to modify it to save it from killing itself, but it won't.  Get used to seeing the high numbers and know that it's normal.  If you want to see lower city temps add a second fan and/or install a manual switch to run the fan so it doesn't wait for the high temps to hit.  You could also install a different temp sensor to do it automatically.

 

Coolant dripping is not normal.  It could just be that the mechanic over filled it and it's purging the excess from the coolant overflow bottle, or you have a leak.  You'll have to track down where it's coming from to know.  Did you replace the radiator because yours was damaged or were you just seeking lower temps?  I'd trust an old Honda rad. more than a new China rad, just assuming that "eBay radiator" means it's Chinessium.  I've seen some of the fancy all aluminum Chinese radiators cause overheating in cars and a cheap Chinese 'normal' replacement one cured them.

I'd find a local shop that does quality recore work, but they are getting hard to find around here now that the newer automotive radiators have plastic tanks and aluminum cores. I'm lucky to have two near me. My bird has the original radiator. It is fairly low mileage too. It just hit 25k on a trip a few weeks back.

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9 hours ago, FTM said:

Is there a chance that the coolant dripping is a sign of something catastrophic (gasket etc?) and also, theoretically is the bike good to ride now if I drive it on open road where fan doesn't have to come in?

 

Not really.  Coolant coming from the center of the bike is likely from the overflow bottle.  From the front could be the radiator or a hose.  Mid-bike on the left side could be the coolant pump.  It sounds like your system is running normally...likely don’t have all the air out.  You pretty much have to fill, run bike, file, run bike, etc. until the system runs normally with no overheat or boil over.  It’s supposed to be self-bleeding, but I don’t think it’s meant to handle that much air in the system.

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Mine has always been a scorcher, especially in traffic.  I rode mine to and from work daily, about 30 minutes each way, most of it redlights, and the heat from the engine sucks (plus seeing that gauge always creeping towards red.)  You should try drag racing.  Everybody would make a pass, head to the pits, and instantly put blowers on the bikes.  Of course, when your air temp is 90+ and you were just WOT through a burnout and a pass, I'm surprised it didn't set off thermonuclear warnings at the Pentagon.

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Something I thought about doing on the turbobird was fabing a heat shield to go between the radiator and the header.

Something louvered to allow airflow but solid enough to block radiant heat.

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Well, first thing’s first....what happens if you let the bike idle?

 

Does it boil over?

Does it get to the H but the fan kicks in, brings it down some, then shuts off in a narrow heat/cool cycle on the temp gauge?

 

There’s nothing wrong if the bike runs hot...that’s its nature.  It took me a while to learn that.

 

I could walk you through how to install a fan motor override/bypass if you want peace of mind, but it shouldn’t be necessary if nothing is wrong with the system.

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On 5/25/2018 at 8:36 PM, FTM said:

Or could it be the faulty fan, since the mechanic mention something about the fan needing the replacement on my next service.

This could be something.  I would call and ask him to explain.

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2 hours ago, Aunt Zero said:

Well, first thing’s first....what happens if you let the bike idle?

 

Does it boil over?

Does it get to the H but the fan kicks in, brings it down some, then shuts off in a narrow heat/cool cycle on the temp gauge?

 

Tested this today, went for a short ride. Expressway ride, bike kept completely normal temp like it always does. Pull up, shut the bike down, nothing happened. Then went on a slower ride, temp got up very close to fan switching level, pulled over, let the engine run, gauge was at 103'C meaning the fan should've started to operate, nothing happened, 105'C still nothing, 107'C still nothing, shut the bike off, coolant dripped out from above the center stand.

 

1 hour ago, blackhawkxx said:

This could be something.  I would call and ask him to explain.

 

Yeah, I will...don't know what attitude to take though.

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what side are you seeing the leak from?left hand side,side stand side...could be either a hose not tightened enough or the water pump seal starting to fail.put the bike on centre stand and have a look around using a bright torch for signs of any leaks.right hand side could be the overflow hose not sealing on the radiator properly.remove the side fairings if you can   

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And don’t trust what the mechanic says at face value.  It’s an easy test if the fan doesn’t work, plus it has its own fuse.  A faulty switch or switch circuit will prevent the fan from turning on.

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12 hours ago, FTM said:

Yeah, I will...don't know what attitude to take though.

Show up with an AR15 pointed at his head and demand answers.

 

Or just call him and ask what it was that made him suspect it would be needing replacement soon.

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15 hours ago, silverbird1100 said:

The heat gets talked about so much, hardly anyone ceramic coats their headers.  Is this because it doesn't work or nobody want to pay $300 to have it done right? Or both?

I'd say it's the lack of data about how much it helps and the money combined.  If coating was cheap we'd probably have more users and more data.  Since the header is so close to the radiator some exhaust heat must be transferring at low speeds, but no clue what the actual impact on coolant temp is.

 

If anyone with a totally stock FI bike wants to do temp comparisons I'm game.  From memory my header tubes dropped from around 400F to 300 at idle with the coating.  I never thought to check the temp of the radiator before/after.  This would be easy to do with an infrared thermometer, don't even have to take anything apart.

 

Header wrap made a pretty big difference in felt heat on my 999.  When I gutted the muffler it dropped more.  I assume slip-ons would drop the Bird's header temp.

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On 5/26/2018 at 12:26 AM, XXBirdSlapper said:

Even when it's over 95f + and humid

Humidity often comes up in car/bike conversations and engine heat.  While humidity makes a huge impact on what your body feels I don't think it'll change engine temps.  Your 95 and an Arizona 95 will feel very different to a person, but about the same to a radiator.

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  • 3 years later...

Hi I have just bought a bird 1999 fuel injection drove back 70mile no issues temp all good . When I stopped there was coolant coming out overflow for about 15 seconds. Bike was stood for 3years then MOT and did 100mile  and left for a year . Is this just the bike clearing it’s throat so to speak or should a check specific things? 

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