Running hot - - - HELP

[Hobicus]

Ok.. so my friend has an 02XX

Since he's gotten it, it seems to run hot. I posted about it before. Basically, if you start it and let it idle, it will warm up, and evenutally hit about 220, and sit at 220. In contrast, my 02XX started at the same time, hits 209. His does not cool down when you crack the throttle like mine does, and when running side by side in town, his runs from 10 to 15 degrees hotter than mine.

His bike seems to cool considerably slower than mine. When running on the interstate with full wind, his will drop to 185 just like mine, but only after about 5 minutes of clean air. Mine drops in under 2. Mine bleed heat when it gets warm.. It will burn your ankles if you're only wearing sneakers. His doesn't.

I had it here this weekend, in an attempt to resolve the issue.

So far, here's what's been done:

Flush and fill

Pulled the radiator and back flushed it. As in.. Madison city water flows through it at 60 PSI without obstruction.

Replaced the thermostat. The one that was in it wasn't closing (explains another issue, it would hang at 165 for quite a while before getting warmer, mine hangs at 176) but when I boiled the replacement and the old one they both open to the same size.

Swapped temperature sensors between his bike and mine. Same readings.

Swapped water pumps between his bike and mine. Same problem.

The entire thing leads me to believe that it's got an obstruction that's causing it to not flow water at the proper rate.

Anyone else have any other ideas?

[azxx]

It maybe running leaner, while mine is carbed and a different beast, my XR650R jetted lean makes lots of heat now jetted on the rich side I can't feel any heat unless I sit still for over 5 min, no fan on these. Ignition timing can make a big difference allso. My 2 cents.

[KA]

Sounds like you checked pretty much everything.

Did you check the hoses for obstructions? I've seen hoses that looked good but collapse when the engine ran. Might check that out.

Do the fans both kick on at the same temp? I don't have the digital dash but think there might be a pot to adjust the readout.

Good Luck

[arcticflipper]

All Grey imported bikes into South Africa has the same problem, they were not designed for our conditions. This is the reason why we try and purchase OEM Honda's.

The only way to find out if the bike is a grey import is to take it to your Honda Dealership, and have the numbers checked. If the bike is on the Database, then we can look more into this problem, else if not, then that's the reason why it's running so hot.

There isn't much that we've been able to do with regards to this on Grey imported bikes.

[nickc2s]

Do you use synthetic oil and your friend not? Synthetic cools my XX from a heat spike much faster than mineral oil.

[Ronnie]

I don't think its running hot..

[Pete in PA]

wow, that's more then I would have done, especially swapping my parts into his.

I also say it's running leaner then yours, not much else left. You didn't swap insturments though did you? :wink:

Might be better to actually stick a thermometer in both bikes coolant while running in the driveway and check when fans come on.

[bartonmd]

I too would say he's running leaner than you... yours is carrying extra heat out the exhuast in unburnt fuel and his cooling system has to take car of all of it...

Mike

[Hobicus]

Remember that the bikes are both EFI bikes. His pulls as hard as mine, which would lead me to believe that it's not a problem with fuel mixture. I can run some sea foam through it, though.

We are both running the same type/brand of oil (I did his last oil change).

I'll double check the hoses, and make sure none of them are bent. I was intrigued to find that the water pump has 2 hoses on it,a "bypass" hose and a main hose.

The only thing I can think of to do is to back flush the block, and see if there's anything blockage wise that comes out of the engine.

[bartonmd]

The difference would be you running a PC and exhaust and him running completely stock right?

Yours runs richer than his if this is the case...

Mike

[Hobicus]

Mike, both of mine have had the same behavior temperature wise before and after I put the PC III/exhaust on it. That's why I don't think it's mixture.

If I leave this bike sitting at idle, when it's 80 degrees out, the temperature will run up to 230. Usually, when that happens, you can rev the throttle and the temperature will drop 5- 10 degrees because the water pump is under powered at idle. This bike does not do that.

[bartonmd]

oh... gotcha...

has his sat for any extended kind of time? especially sat with non-purified/distilled water in the coolant?

I guess you could try and do the back-flush thing on the block next like you were thinking... I'm out of ideas... you did all the common stuff...

Mike

[Hobicus]

has his sat for any extended kind of time? especially sat with non-purified/distilled water in the coolant?

Do not know for sure. He bought it used from the Stealer, and I bet he hasn't put more than 3k miles on it, it's got 15k.

What I DO know is that both the temperature sensor and the old thermostat had some build up on it, so it's quite possible.

I was thinking that maybe a good coolant flush solution would be helpful.

[bartonmd]

that could be helpful... I guess that's what I'd try next...

Mike

[Moriartii]

I have a 97 bird with 30K on the clock. When I got it in April I did a major coolant flush on it. This involved doing Warchild's recommended procedure. However when I found out that Dex Cool may be bad I flushed it again and used the premixed bottles of Honda coolant from the stealer. I also put in the recommended amount of Water Wetter. Throughout the process I burped the shit out of the system ensuring no bubbles appeared.

My results prior to flushes where the temp gauge ran at about 3/4 of the way up the gauge when at full temp in traffic. After flushes the gauges NEVER goes over the halfway mark. I also live in Austin Texas so it gets pretty warm in traffic.

You may need to just flush the shit out of the system, use Honda coolant and some water wetter?

Kinley

[cbrxxquad]

Throughout the process I burped the shit out of the system ensuring no bubbles

Kinley

+1

[CBR-RR-XX-CESS]

Might be better to actually stick a thermometer in both bikes coolant while running in the driveway and check when fans come on.

Rich, I would use a thermometer to verify that the gauge matches the temp reading as a starting point. Or was this done already?

[Hobicus]

I've done the burp process enough times to know I've gotten that done correctly, and how to identify when it just needs burped.

I pulled the radiator and completly flushed it, so now I'm thinking that I'm going to have to back flush the block with a garden hose.

[cbrxxquad]

Just thought of something,,that damn wire loom terminators are all grounds for stuff and the lack of a good connection to the fan switch is a ground so may check for corrosion. I had a problem with my fan not comming on at the right time I traced to the one by the engine. I ended up removing both and they were bad. No more grounding problems.

You know now that I think about it that would sure cause problems with the regulator if there was intermittent grounds with all the electricals too

[tomek]

I would try swapping ECUs ,see if that changes anythink.Also I would not dismiss role of mixture and ignition timing ( pc). There is no 2 bikes that have exactly the same ignition and cam timing plus run excatly the same mixture.Unless you blueprint them.

Little things like amount of carbon deposits in combustion chambers and exhaust valve can effect running temperature.

Years ago,I and Peter run in the heavy traffic in 90 deg,his bike was all stock ( back then), mine had full system ,PC2 with 93 octane map.Mine did run cooler.( analog gauges,3/4 vs almost all the way to the high)

[rickrad]

Duder,

SELL IT!

[Hobicus]

SELL IT!

If it were mine, yea.. I would.

I'd LOVE to know what's causing it, though.

[madrazcbr]

Hi Hobicus,

I have been following your article closely. How is your friend 02XX ? Is it still the same with the temperature ?

I am very interested on things that can be done cause mine also a 02XX Euro model Red colour(could it be red). I am in Malaysia and the temp here is around 86F. I am always try to be fair so thats why I am using Motul Semi Synthetic 10-40, not mineral not fully synthetic. Fair right. Your friend symptom are the same as mine.

When I bought mine new in 02 and with the factory 50/50 coolant, the temp can sometime shoot up to 250 - 260F region. After reading article in this forum(thank you guys) I have change the coolant to ICE COOL cause I am unable to get Water Wetter. I still have problem after that which is due to the mechanic does not burp the system. After it was burp correctly the temp improve compare to using the original factory coolant.

The improvement is that it is now having the same symptom as your friend 02XX which includes taking a longer time to cool down to 190 on an open road, it will go up to 220 it is left idle and it definitely climbing, etc. yes exactly the same. I still called it improvement as it is now take a longer time to reach 250. It still reach there if the bike is in idle or in start stop traffic. It cool faster as previously it took around 1.5 to 2 hours and now around 30 minutes. It goes down to 190 in open road as oppose before it only go down to 205. I try to live with it but cannot. I wrote in to this forum.

After Joe advice that there it is nothing to worry about, I just enjoy the bike. Although sometime I do feel scared when I see a traffic jam. I cannot join a group ride as a certain time the group will need to go down to 50MPH for a period of time especially when approaching town. These will help the temp to shoot up to 250F. Whatever it is I still love my XX and enjoying it more day by day.

I cant sell it as it is very expensive now to buy another bike with 120% sales tax. So if you do find a way to improve the temp of your friend 02XX, hope you can share it with me.

I was being told cooler bike go faster.