Cooling system help

[acook3323]

05 250 temp guage wont go above abput 1/4 cooling fan wont turn on. Flushed the system and bled it as well

[juliusmichaelhonrada]

Originally Posted by acook3323

05 250 temp guage wont go above abput 1/4 cooling fan wont turn on. Flushed the system and bled it as well

i dont really see that as a bad thing well in my case because im in a tropical country hehe ,you can check the thermostat if its not closing. fan turns on just about the redline if its an ex250f , if its a zzr250 fan turns on at half temp

[acook3323]

Originally Posted by juliusmichaelhonrada

i dont really see that as a bad thing well in my case because im in a tropical country hehe ,you can check the thermostat if its not closing. fan turns on just about the redline if its an ex250f , if its a zzr250 fan turns on at half temp

I ran the bike for about 20 minutes amd didnt crack 1/4 im just worried that something may not be readong roght and it will overheat.

[Triple Jim]

The temperature gauge with its sensor, and the cooling system thermostat, and the fan switch are three different things. If the gauge malfunctions, the cooling system thermostat can still control the coolant flow through the radiator, and the fan switch can still turn on the fan.

Idling in neutral will test all three, within reason. You should see the temperature gauge climb slowly, and as JMH said, when the gauge gets high enough the fan should come on. As long as the temperature then drops somewhat, you know the cooling system thermostat has opened to let coolant flow through the radiator.

All three can be tested if necessary.

[juliusmichaelhonrada]

Originally Posted by acook3323

I ran the bike for about 20 minutes amd didnt crack 1/4 im just worried that something may not be readong roght and it will overheat.

yeah you may have a malfunctioning gauge , or a bad radiator ground that the sensor needs to operate correctly

[acook3323]

Originally Posted by Triple Jim

The temperature gauge with its sensor, and the cooling system thermostat, and the fan switch are three different things. If the gauge malfunctions, the cooling system thermostat can still control the coolant flow through the radiator, and the fan switch can still turn on the fan.

Idling in neutral will test all three, within reason. You should see the temperature gauge climb slowly, and as JMH said, when the gauge gets high enough the fan should come on. As long as the temperature then drops somewhat, you know the cooling system thermostat has opened to let coolant flow through the radiator.

All three can be tested if necessary.

It only reads up to 1/4 and doesnt move at all

[Triple Jim]

Yes, so your temperature gauge sensor or the gauge itself may have a problem. My point is that's not related to the thermostat that controls water flow, or to the fan thermostat.

[Ram Jet]

Originally Posted by acook3323

It only reads up to 1/4 and doesnt move at all

Try covering the radiator with a piece of cardboard and tape and take it for a short ride. You should see a change.

http://shop.watt-man.com/Thermo-Bob-...EARS-TB3-N.htm

I'm considering installing one of these kits on my 2007.

[taz]

don't wast your money

[Ram Jet]

Originally Posted by taz

don't wast your money

Have you had experience with this kit? I sure don't want to toss-away $129.00 on snake oil. This guy really talks-up a storm about this product.
A Sucker born every minute?

[juliusmichaelhonrada]

Originally Posted by Triple Jim

Yes, so your temperature gauge sensor or the gauge itself may have a problem. My point is that's not related to the thermostat that controls water flow, or to the fan thermostat.

hahah yeah i thought his temp never goes up to 1/4 could be a free flowing thermostat

[Triple Jim]

True, JMH. When in doubt, test the parts.

Adam, you can test the thermostat by removing it from its housing and putting in a pan of water on the stove. By the time the water boils, you should see the valve open.

You can test the fan switch and the gauge sensor similarly, if you have an ohm meter.

Here is a page that describes the cooling system, and it has a troubleshooting link:

http://faq.ninja250.org/wiki/Cooling_system

[greg737]

Originally Posted by Ram Jet

Have you had experience with this kit? I sure don't want to toss-away $129.00 on snake oil. This guy really talks-up a storm about this product.
A Sucker born every minute?

I'm betting TAZ doesn't know what he's talking about.

Here's the deal with the Thermobob:. All modern water-cooled vehicles (both cars and motorcycles) have small radiator bypass lines built into the cooling system. The EX250, which is an old design, does not have a small constant-flow radiator bypass line. The lack of this design feature causes the EX250's thermostat to act in strange ways, the foremost of which is that the thermostat is often full open when it really doesn't need to be, which is why the EX250 has a reputation for being "a cold blooded reptile" (except when you live in a tropical climate).

I've had a Thermobob on my '05 EX250 for about 7 years now and I really like the difference it makes in the bike temperature behavior. I even did a do-it-yourself constant bypass line on my '93 Suzuki GSF400 which made that bike better also.

[Ram Jet]

[QUOTE=greg737;1168177]I'm betting TAZ doesn't know what he's talking about.

Here's the deal with the Thermobob:. All modern water-cooled vehicles (both cars and motorcycles) have small radiator bypass lines built into the cooling system. The EX250, which is an old design, does not have a small constant-flow radiator bypass line. The lack of this design feature causes the EX250's thermostat to act in strange ways, the foremost of which is that the thermostat is often full open when it really doesn't need to be, which is why the EX250 has a reputation for being "a cold blooded reptile" (except when you live in a tropical climate).

I've had a Thermobob on my '05 EX250 for about 7 years now and I really like the difference it makes in the bike temperature behavior. I even did a do-it-yourself constant bypass line on my '93 Suzuki GSF400 which made that bike better also.[/QUOTE

You said very concisely in one paragraph what it took this guy at Thermobob 12 pages with graphs and visuals to do. You basically said what he said only I understand your explanation far better. Your 7 year experience with this product has cinched-up a sale for Thermobob. Thanks.

Bill

[arnvc]

also have a therm o bob, keeps water temps within aboot 20 degrees, stock thermostat had aboot 90 degree swing on average ride . stock thermostat diameter at hose is aboot 3/4 inch, therm o bobs is 5/8 inch diameter.

[acook3323]

Originally Posted by Triple Jim

True, JMH. When in doubt, test the parts.

Adam, you can test the thermostat by removing it from its housing and putting in a pan of water on the stove. By the time the water boils, you should see the valve open.

You can test the fan switch and the gauge sensor similarly, if you have an ohm meter.
Do you know the part # foe that sensor. I want to make sure im looking for the right thing
Here is a page that describes the cooling system, and it has a troubleshooting link:

http://faq.ninja250.org/wiki/Cooling_system

[Ram Jet]

Originally Posted by arnvc

also have a therm o bob, keeps water temps within aboot 20 degrees, stock thermostat had aboot 90 degree swing on average ride . stock thermostat diameter at hose is aboot 3/4 inch, therm o bobs is 5/8 inch diameter.

I'm getting it as soon as payday rolls around!

Bill

[acook3323]

Originally Posted by Triple Jim

The temperature gauge with its sensor, and the cooling system thermostat, and the fan switch are three different things. If the gauge malfunctions, the cooling system thermostat can still control the coolant flow through the radiator, and the fan switch can still turn on the fan.

Idling in neutral will test all three, within reason. You should see the temperature gauge climb slowly, and as JMH said, when the gauge gets high enough the fan should come on. As long as the temperature then drops somewhat, you know the cooling system thermostat has opened to let coolant flow through the radiator.

All three can be tested if necessary.

Do you happen to have the part # just to be sure im getting the right part

[Triple Jim]

I do not, sorry. Which one are you trying to identify? A gauge stuck low could be:

1. A defective gauge
2. A defective sending unit for the gauge (gauge temperature sensor)
3. A thermostat stuck open (the one in the thermostat housing that controls water flow)

Are you saying that if you let the bike idle or drive it around very slowly for like 15 minutes, the gauge never gets up over about 1/4 of full scale?

[acook3323]

Originally Posted by Triple Jim

I do not, sorry. Which one are you trying to identify? A gauge stuck low could be:

1. A defective gauge
2. A defective sending unit for the gauge (gauge temperature sensor)
3. A thermostat stuck open (the one in the thermostat housing that controls water flow)

Are you saying that if you let the bike idle or drive it around very slowly for like 15 minutes, the gauge never gets up over about 1/4 of full scale?

I do rides back and forth of 25 to 50 mph and it doesnt go above 1/4. It may be fine but i just want to be sure before im stuf on the side of the road due to overheat. Im looking for the guage temp sensor

[Triple Jim]

There should be a procedure for checking its resistance with a meter while heating it in water. Offhand, I can tell you that its resistance should decrease when it's heated.

Checking the coolant thermostat is also simple, as I said above. Take it out and look at it. When cold, it should be closed. Put it in a pot of water on the stove, and by the time the water is boiling, you should be able to see that it's opened. In your case, if it's causing your engine to stay too cool, you'll see that it's open at room temperature.

If I keep my 250 between 25 and 50 mph, the temperature gauge behaves about like yours. I'd hate to see you buy a new sensor, then find it doesn't change anything, so you buy the next thing, and end up replacing everything and find out it was all working properly.

[choneofakind]

Another pro-thermo-bobber here.

The bike no longer rides differently in the cold vs the heat. I no longer need cardboard on the radiator in late fall. I don't have to ride gently for nearly as long when I first start it. The temp gauge comes up and stays there, no questions asked. I was even able to make the gauge work properly with it, so it's literally no difference from the cockpit, aside from a smoother running engine. The bikes should come from the factory like this.

[Ram Jet]

Originally Posted by choneofakind

Another pro-thermo-bobber here.

The bike no longer rides differently in the cold vs the heat. I no longer need cardboard on the radiator in late fall. I don't have to ride gently for nearly as long when I first start it. The temp gauge comes up and stays there, no questions asked. I was even able to make the gauge work properly with it, so it's literally no difference from the cockpit, aside from a smoother running engine. The bikes should come from the factory like this.

Is installation difficult?

Bill

[choneofakind]

No, not at all. If you're capable of flushing the coolant system, you're capable of installing a thermobob.

[Ram Jet]

Originally Posted by choneofakind

No, not at all. If you're capable of flushing the coolant system, you're capable of installing a thermobob.

I can do the cooling system flush. I feel that if I can successfully adjust the valve clearances on the 250 I could accomplish a moon launch! This is definitely the most difficult valve clearance maintenance I have ever run into. That includes a 1959 Alfa Romeo Spyder Veloce and a Suzuki GS750. Installing Thermo Bob ought to be up there with a beer blast.

Thanks,

Bill