Totally and completely lost on overheat issue

[surlistyc]

I've posted here before and have gotten great and timely responses. But my problem still persists. I can only ride it about 20 minutes at a time, no matter the speed or if it's stop and go traffic.

'03 ninja250
26k miles

So here is what I have done so far
-Flushed the system and it's as clean as it gets
-Topped off coolant
-Coolant is brand new
-Found out the owner before me took out the thermostat and didn't replace it. So I recently did. (last night)
-Oil level is fine
-Radiator doesn't leak
-Radiator Cap looks brand new
-Changed spark plugs
-Adjusted valved and tensioner (whole different problem)
-I am 99% sure the water pump works fine

I just got back from a "test" ride and now it "feels" like it's hotter than before. like burning my right leg when on the foot peg.

So the guy who owned it before me was apparently the DIY type that half assed....everything. he rigged the fan to come on when you turn the ignition on, so the fan runs constantly. like I said earlier, he took out the t-stat and didn't replace it. electrical tape as a wiring harness. (literally through the whole bike)

Guys, I am so lost as to what to do, short of taking it to a mechanic and signing over my first born that I don't even have yet.

[k-os]

When you replaced the coolant I'm assuming you also bled any air from the system? Do you know that the water pump is working and pumping coolant throughout the system?

[surlistyc]

Yeah I bled all the air out.
and I am 99% sure the water pump is working. I guess I don't have any justification behind it besides after draining the coolant a few times with BOTH drain bolts, both of them spewed coolant. and I think I read somewhere if the pump isn't working it doesn't get to the t-stat, but that doesn't make sense.

If anyone can answer, do I have to special order a radiator cap? or are they all universal?

[Lychee]

Are you sure it is overheating? My pregen's temperature gauge goes way beyond 12 o'clock when at a stop light. There is a good 30 degrees of normal "play" in the needle location depending on the riding situation.

Forgot to add: have you checked for a leak in your right exhaust pipe?

Again forgot to add: The frame gets pretty hot through normal riding.

[surlistyc]

I'm pretty sure it's overheating. the needle will get to the line before the red, and after about another 5-10 minutes of riding, it'll get about 1/5 into the red, and any longer it gets halfway. I've only ever let it get halfway into the red before I turn it off (that happened only once) because I think it's going to have a small nuclear explosion.

I haven't check for a leak in the exhaust. but every time I get on the bike I do a quick visual inspection of the ground around/under my bike, and the only thing I normally see, (sometimes) is coolant from the overflow.

I understand the frame gets hot while riding. but after I put the t-stat in, there is a definite change in how hot it gets now.

Thanks for the replies.

[DaBlue1]

Replace the radiator cap. If the cap will not allow the system to pressurize properly, it will release pressure at a lower temp.

The new gen and pre gens share the same cap. Stock 1.1 BAR / 16 PSI (SAE range 14-18 PSI) radiator cap # 49085-1066 can be replaced by

Stant's 10233
Prestone's RR-33
CARQUEST 33044
Gates 31336
Gates Canada 31336
NAPA 703-1406
Stant (Carded) 11233
Stant (Carded) 70233BL
Stant (Carded) 70233RD
CST 7516(@ AutoZone)

[Somchai]

you should check your oil if you see water in it and also check the water for oil in it. if one of this appears then it looks like if your cylinder head gasket is blown and maybe this is the reason for the owner before you to take of the thermostat.

[surlistyc]

I've looked through the sight window, and I have seen no discoloration/milkiness/separated fluids. But I did end up getting a new overflow res about a month ago because the old one had a leak. well I looked earlier today and there was some "oily" looking stuff in there. although I've drained the coolant about 3 times in the last 2 weeks and have not seen 1 drop of oil in it. I've always heard with blown head gaskets that it's not a "oh I think I might have blown a head gasket." it's more so a "Oh ****, I definitely blew a head gasket."

The thing with the oil... about 3 weeks ago, I noticed my bike "leaked" literally a total of 3 drops in the span of like 2-3 days. so I topped off the oil. well I looked today and saw that there was absolutely no oil in it, so I refilled it again figuring, "derp that's probably why it's running so hot" Nope. it still runs hot but now with oil.

I've had a friend that is pretty proficient with bikes (he used to race dirt bikes and worked at a bike shop for a while. I take his word over 90% of mechanics) look at it multiple times, and he's seen no indication of a blown head gasket.

He did tell me today though, that I might have to clean and rejet my carbs, and that it makes the fuel too rich/lean I can't remember which one. His justification was, last night we put in new spark plugs and the old ones had a weird discoloration that made him think the bike is running too rich/lean.

Although my rad cap looks pristine, I'm going to get a new one tomorrow, just so I have the peace of mind knowing that, that's not a possibility.

Thanks again for all the responses, please if anyone has any other suggestions, I would be more than grateful to hear them. I'll let you guys know what's happening every step of the way. I've seen so many posts with overheating and every one of them seems to get resolved. I believe in the power of the ninja 250 (ninjette.org) community.

[k-os]

If you checked today and found that there was no oil in it, it sounds like you may be burning oil. Do you notice any blue tinted smoke coming from your exhaust?

The other thing is, when you checked the oil level was it with the bike perpendicular to the ground (in your case on the centerstand)? If you checked it while it was on the sidestand and thought that it was low on oil and added more, then you've overfilled it and will need to drain some out.

[surlistyc]

since I've owned this bike, for about 2.5-3 months now. I've never seen the exhaust smoke.

I've checked the oil a couple different ways. I used to with the centerstand until I heard everyone say that it kind of sits off balance from front to back. I will usually just hold the bike straight up myself, or have someone else hold it straight for more accuracy.

When I filled the oil today, it took about half a quart. I'm not sure the last time the oil was changed and I haven't checked the oil filter to see if it is clogged. do you think that could be a huge culprit as to why my baby is overheating?

Do I get oil filters for ninja 250's from autozone?

[surlistyc]

The rad cap was just tested at autozone and it works fine.

[Motofool]

Your radiator has hard deposits.

http://www.ninjette.org/forums/showp...39&postcount=8

[surlistyc]

Motofool, can you elaborate. I never use anything but coolant, or distilled water. (but if I have to use distilled water for some reason, I have always drained and put in 50/50 within a day or two.)

[Motofool]

The system is very simple: all the heat generated in the engine must be transferred to the air via coolant and radiator.

If there is not enough air-radiator transference, the temperature of the coolant keeps increasing, which is sensed by the sensor in the T-stat.

Hard deposits in the radiator introduces a double problem that decreases the heat transfer rate greatly: reduced flow of coolant and heat conductivity.

The pump is centrifugal; hence, it will produce reduced flow when restriction in the circuit increases, even if it is in perfect condition.

Are you sure of what the previous owner did about replacing the coolant periodically or adding hard water?

[surlistyc]

Honestly I have no idea if the previous owner ever changed the coolant, or added hard water. When I very first changed the coolant, it was the nastiest coolant I have ever seen.

How would you go about eliminating hard deposits?

[Asspire]

CLR

[Motofool]

Originally Posted by surlistyc

....How would you go about eliminating hard deposits?

I am not sure about how to clean it, since it is aluminum and the calcium deposits need some acid agent for removal.

A clean new radiator is working at full capacity (they make it almost too small to do the job); that is why the fan for low air flow situations.

Strong deposits on the engine's cylinder and head making difficult the heat transfer into the coolant wouldn't heat up the coolant much, but would induce an engine seizure.

Old coolant decomposes and induces deposits and rusting of internal parts.

I hope it is not your radiator, but if you have verified that everything else is functioning properly, it may very well be.

A not very practical way of testing that is pumping water to and from a big container, like a 55 gallons drum for a while and see how the overheating behaves.

May be trying a more effective coolant could help a impaired radiator.

[alex.s]

when kevin's 636's crank bearings were on the way out, it ran super hot. something to think about if you find the radiator is clean

[surlistyc]

I have been using the peak 50/50. Maybe actual distilled water and water wetter would work better?

Thanks for the tip Alex. but if it actually comes to that point, I'm going to sell this bike, and put the money towards a cbr600

[Motofool]

Originally Posted by surlistyc

.....water wetter would work better?

Possible so.

It has been super-hot here in Florida, where we don't really need the anti-freeze characteristics of the coolant: we need high heat transfer rate and high boiling point.

My 2007 is not over-heating, but it isn't far from reaching that point at slow regimens, like parking lot riding.

[Asspire]

Originally Posted by surlistyc

Honestly I have no idea if the previous owner ever changed the coolant, or added hard water. When I very first changed the coolant, it was the nastiest coolant I have ever seen.

How would you go about eliminating hard deposits?

1. disconnect upper and lower rad hoses
2. plug lower rad outlet
3. fill rad with CLR
4. let soak for about 30 minutes
5. rinse

also works great on plugged up heater cores and old copper rad's.


also, might be a stupid question, but its not running lean is it?

[surlistyc]

To me, that's worth a shot.

Where abouts in Florida are you motofool

And also to give a better description of how it overheats;
I ride for the first 10 minutes just fine, the needle stays at about 10-11 o'clock. Then after that, it jumps (as im riding) to about 1-2 o'clock. At this time I have been riding for about 15 minutes. I'll get stuck at the slow ass clearwater stop lights for a few minutes then the needle will hit the white line before the red. I'll get going and the needle will naturally come back down to about 1-2 o'clock. I'll hit another light and the needle will just barely be touching the red. this is about 20-25 minutes of riding. I'll say "****" then head home, the needle will stay just under the white before the red until i reach home. if it takes me a little longer to get home, (about a total of 30+ minutes of riding) I'll park the bike and watch the needle get about 1/4-1/2 into the red.

[surlistyc]

Asspire, My friend thinks it is. and I take his word for it. so we're planning to do some backdoor tests to kind of get a feel before we delve into the carbs. He's going to set the choke just right, and I'm going to test ride it and if it stays cool while riding, or stays cool longer, then that just might be the culprit.

Seriously, we're going to get this working, and this thread will be the end all to ninja 250 overheating issues.

[Jim Moore]

It may be running lean, but I don't think that's causing your overheat. How much is a water pump? That would be my next try. Then a used radiator from a parts bike.

[DaBlue1]

Originally Posted by surlistyc

....So the guy who owned it before me was apparently the DIY type that half assed....everything. he rigged the fan to come on when you turn the ignition on, so the fan runs constantly. like I said earlier, he took out the t-stat and didn't replace it. electrical tape as a wiring harness. (literally through the whole bike)

So have you fixed the fan issue or inspect the temp sensor or electrical connections at all?

Here are a couple of good things to read that may help in your troubleshooting the system. Sometimes you may have to double check the work.
http://faq.ninja250.org/wiki/How_do_...ling_system%3F
http://faq.ninja250.org/wiki/Cooling_system

[Motofool]

Originally Posted by Asspire

....
3. fill rad with CLR

Copied from the FAQ's of that site:

"Can I use CLR to clean out my radiator?

No, CLR should not be used on a car radiator for two reasons. First, CLR may not be compatible with the internal metals of the radiator. Second, it could have adverse effects if the CLR is not rinsed out completely."

[Motofool]

Originally Posted by surlistyc

Where abouts in Florida are you motofool

I live and ride along the North portion of South Florida, East coast (I-95).

Yes, I think that extra oil (high level) and extra fuel in the mix will help some, as well as keeping the idle rpm's low and the fins of the radiator straight and clean from debris.

Also, try not pushing the engine too hard while you solve this mystery: the most fuel you burn, the most heat needs to be released to the atmosphere during the same time.

[surlistyc]

Yeah my idle rpm is around 1400

The fan isn't a real issue. I see no problem with it running constantly.

The fins on the radiator aren't bent and it looks fairly clean. I will take an air compressor to it later, but I really don't think it's dirty enough to block that much air flow.

I'm going to try and test the water pump by tomorrow if Isaac doesn't give my part of Florida hell.

If the water pump works fine, my next option is to just go ahead and replace the head gasket. (if I am going to delve into that, I'm just going to replace it anyway, whether it's bad or not)

if still, none of that works. I'm going to richen the fuel through the screws on the carbs that are covered by some epa mandated plugs. I believe it is running lean as when I blip the throttle, it'll hang for a split second then somewhat slowly drop back down. I heard if the fuel was rich it's supposed to immediately drop down just below idle and move back up.

The only other option I can think of is the crank bearings that Alex mentioned. And if that's the problem, I think I'm just going to unload my friends pistol grip 12 gauge into my bike.

besides everything that I have mentioned, is there any other options?

[alex.s]

hmm... crusty radiator + lean carbs = hot bike... maybe the carbs just need to be cleaned...

im wondering what metals clr reacts poorly too? whats in a radiator? brass, aluminum, lead, plastic, some steel? what would react poorly to it? you would definitely need to pressure clean it afterward

[Asspire]

Whoops, warning label wasn't in Canadian so I didn't bother to read it.

I've always used the stuff when cars come into the shop with plugged up heater cores. Does wonders, but then again, not sure about how it reacts with different metals.

a quick way to test for a bad head gasket is to check for combustion in the coolant. Open yer rad cap and stick a set of multimeter probes in the coolant, if you get a voltage reading you've got a leaking head gasket.

[Lychee]

Originally Posted by Asspire

a quick way to test for a bad head gasket is to check for combustion in the coolant. Open yer rad cap and stick a set of multimeter probes in the coolant, if you get a voltage reading you've got a leaking head gasket.

That's a new one.

[surlistyc]

Asspire, I'm assuming this is with the bike running? (to test head gasket with voltmeter)

[surlistyc]

Ok, so with Asspires logic. I need a new head gasket. my multimeter was reading .14 at the highest. I would still like to know how this works though.

[DaBlue1]

Originally Posted by Asspire

....a quick way to test for a bad head gasket is to check for combustion in the coolant. Open yer rad cap and stick a set of multimeter probes in the coolant, if you get a voltage reading you've got a leaking head gasket.

I thought that test was to see if the coolant is going through an electrolysis process, which is caused by stray electrical current. Since the OP has such a high reading, electrolysis would be indicated. OP also said in his first post that the OR, "...rigged the fan to come on when you turn the ignition on, so the fan runs constantly. like I said earlier, he took out the t-stat and didn't replace it. electrical tape as a wiring harness. (literally through the whole bike)...".
It may be possible that there is an electrical problem (i.e. the temp sensor since it is in close proximity of the radiator cap and coolant.

[alex.s]

testing with a multimeter is a way to test the PH level of the coolant in the system. its done with a cold motor, that is NOT running. you check voltage being generated from the water to the engine ground. so one probe goes in the water, the other goes to the frame. if the coolant is too high of PH, it will produce a higher voltage (like 0.1v) high PH levels of coolant damage gaskets and seals and will lead to leaking oil.

im not a chemist but i guess its possible that the PH of the coolant can be changed by leaking oil for example caused by a bad head gasket, however this is one of probably close to a million possible causes. and the fact that you have brand new coolant in there makes the test pretty much all but pointless.

i think blue is on the right track. did the coolant even boil in to the overflow tank?

[surlistyc]

If I ride the bike longer than I think I should. Then I will hear a prominent boiling sound. although I'm not sure if it's boiling in the overflow. But I mean the temp gauge can't be that off. I completely understand that bikes/frames get hot. but I mean, this is ridiculously hot.

I told my friend about the voltmeter deal, and he said it would make sense seeing as when we tried to burp the system it would kind of bubble, (just very slightly) seemingly indefinitely. So the gasket might be damaged JUST enough to not leak any liquid, but enough to get air in the system?

[DaBlue1]

Originally Posted by surlistyc

.... the temp gauge can't be that off. I completely understand that bikes/frames get hot. but I mean, this is ridiculously hot.

In reality all metering gauges should be calibrated on a regular basis and sensors replaced, as some do tend to misread over time, but this would be rare for most motorcycles. Given the fact that your bike has some electrical issues, I'd start looking there. Fix your fan (If it cuts on and off as the engine cools and heats up, chances are your system is working like it is suppose too), test your temp sensor, replace your temp gauge or if you are really concerned about heat, add one that measures in actual numbers (most accurate) as opposed to lines.

As far as a gasket leak, you either have one or you don't. Because of the amount of pressure in the combustion chamber, you will either have oil in the coolant or coolant in the oil.

Do you have any intake mods that may be causing to bike to run a little leaner?

Have a look at these threads. They contain info that may help you find what normal temps ranges are and look like. You may also have to go down the troubleshooting guide and check off each item until you find the problem or faulty component. There is a possibility you are running within normal ranges.

http://faq.ninja250.org/wiki/How_do_...ling_system%3F
http://faq.ninja250.org/wiki/Cooling_system

[Motofool]

I have found this new product:
http://www.permatex.com/products/Aut...ator_Flush.htm

According to the link posted above:

If your reservoir is boiling, your 50/50 mix is reaching 265 degrees.

At idle, the coolant should enter the radiator 30 degrees lower than that, and leave it at 180.

If your radiator is not reducing the coolant temperature 30~50 degrees with the bike not moving, something is wrong.

I agree with the previous post, you head gasket either leaks or not.
If it does, you will see oil floating through the radiator neck when open.
A combustion leak may increase the pressure of the cooling system, but it doesn't have to overheat the coolant.

More reading:
http://www.dansmc.com/watercooling.htm

[Asspire]

Originally Posted by alex.s

testing with a multimeter is a way to test the PH level of the coolant in the system. its done with a cold motor, that is NOT running. you check voltage being generated from the water to the engine ground. so one probe goes in the water, the other goes to the frame. if the coolant is too high of PH, it will produce a higher voltage (like 0.1v) high PH levels of coolant damage gaskets and seals and will lead to leaking oil.

im not a chemist but i guess its possible that the PH of the coolant can be changed by leaking oil for example caused by a bad head gasket, however this is one of probably close to a million possible causes. and the fact that you have brand new coolant in there makes the test pretty much all but pointless.

i think blue is on the right track. did the coolant even boil in to the overflow tank?

if the head gasket is leaking, then combustion will seep into the coolant increasing the ph. I believe anything over .7v is no good. But then again this is from when i used to work on cars (mostly gm's 3.4l) might not work the same for bikes.

I told my friend about the voltmeter deal, and he said it would make sense seeing as when we tried to burp the system it would kind of bubble, (just very slightly) seemingly indefinitely. So the gasket might be damaged JUST enough to not leak any liquid, but enough to get air in the system?

these bubbles, is this when the engine is running???

if the PO has done so much to it, I think it might be wise to have a professional look it over.

[surlistyc]

Well my friend and I have seen no oil in the coolant or anything wrong with the oil, but I am definitely getting over .1v with the multimeter. I'm going to order a head gasket tomorrow. so I might not get it until next week. Please if you guys can bare the wait, that would be amazing. I am doing everything in my power before I take it to a "professional" although they do have tools I don't readily have access to.

The bubbles are when the bike is running.

I changed the oil yesterday, (because why not?) it wasn't the worst I've seen but the filter looked pretty dirty. I took the bike out earlier in between all this rain. My normal test "track" is 6 miles. Normally I could only make it around the track twice before my bike overheats. Well I was able to make it around 3 times and the bike never got in the red (even at stop lights) until after I parked it. the new oil/filter helped a little I am sure. (I wasn't planning on that really fixing anything)

I haven't actually tested the water pump yet, and I probably won't get to it until friday because I have classes, but really I think it's going to be a waste of time. (still worth it though)

What are the chances that it's going to run hot because the fact I am a bigger person? about 250lbs at 6'

I don't have any intake mods, but I do plan on putting on some pods. I know for a fact (or a damn good feeling) that my carbs need to be cleaned, but that will probably be the last thing I do, when I get the new air filters. I really do think my bike is running lean. but as people said before, that shouldn't be the defining factor of overheating.

Seriously guys, thanks for all of your input and sticking with me on this!