Author Topic: Overheating! Please Help! (Read 9267 times)

derekd7987 · « **on:** April 07, 2014, 12:44:23 PM »

So yesterday I rode my 250r I've been redoing over the past 6 months for the first time. I only rode it once when I bought it before I started the makeover. When I bought it it had an ESR 310 kit on it with trx11 porting and pipe. I ride woods so I got a new 310 kit from ESR with trx7 porting and pipe. Yesterday it was about 60 degrees outside and after maybe 15 minutes of riding the temp showed 220 on a new ESR inline gauge. About another 5 or so minutes later it had reached about 250 so I cut it off immediately.

The only time I rode it like it was when I bought it, it was about 55 outside and it seemed to run around 220 but it had aviation fuel in it, regular coolant, and that was on a different inline gauge. Now I am running VP110 and 100% destilled water with water wetter.

I have a 38pwk carb running 1.25 out on air, 48 on pilot and 172 on main and I think the needle was DGH with clip in the middle.

Where would you guys start? Should I measure temp some other way just to rule the gauge out first?
Does that jetting seem close?
How should I check the cooling system?

Thanks in advance,

Derek

rablack21 · « **Reply #1 on:** April 07, 2014, 01:00:26 PM »

I would check and make sure the gauge is accurate first, perhaps use an IR thermometer if you have one. I live in East TN and my jetting was very similar to yours with the same setup. I would make sure that your water pump is working. With the engine running, squeeze the lower hose and rev up the engine some. You should be able to feel the hose trying to suck itself together. Also, make sure you have no air bubbles trapped in the system. Did you run it for a couple minutes with the rad cap off so it could cycle the coolant and release air bubbles? This should be a good place to start.

derekd7987 · « **Reply #2 on:** April 07, 2014, 01:06:23 PM »

thanks black. Where should I point the IR thermometer, just on the cylinder anywhere? Ok I will try squeezing the hose while revving it and see how it feels. On the very first start up and for all the other stationary heat cycles during break in I did allow it to idle with the cap off.

rablack21 · « **Reply #3 on:** April 07, 2014, 01:15:43 PM »

Get a feel for the temp in a few different locations. Check in around the top of the head, right where it comes out around front, check it at the gauge itself, and check it on the top tank where it goes into the radiator. You will know pretty quick whether the gauge is off or not.

jcs003 · « **Reply #4 on:** April 07, 2014, 03:31:23 PM »

make sure your radiator cap is in good working order.

john

derekd7987 · « **Reply #5 on:** April 07, 2014, 03:36:34 PM »

Is there any way to really check the cap itself?

jcs003 · « **Reply #6 on:** April 07, 2014, 04:15:38 PM »

Quote from: derekd7987;31092

Is there any way to really check the cap itself?

take it to a radiator shop and they will pressure test it.

john

rablack21 · « **Reply #7 on:** April 07, 2014, 04:19:25 PM »

Also, most of your auto parts stores can test it for you as well.

Emullen · « **Reply #8 on:** April 07, 2014, 11:04:00 PM »

Inspect your water impeller also. I had an issue with the fins being bent and and not circulating / pumping the the water. I chased the problem for awhile

derekd7987 · « **Reply #9 on:** April 24, 2014, 10:05:07 AM »

Hey guys. Hopefully get to check the quad today to see if it actually is overheating. Been really busy and had no time the past few weeks.

I have a question tho that is probably a stupid one. The inline temp gauge, does it only measure the temp of the coolant when passing through? The reason I ask is this morning I looked at it before I left and the gauge showed 65 degrees with the quad just sitting in my garage. It was only about 45 degrees in my garage this morning. Should the gauge read basically what the outside air temp is or should it only have a reading with the engine running and coolant passing through it?

rablack21 · « **Reply #10 on:** April 24, 2014, 10:16:59 AM »

It is reading the temp of the coolant that is running inside it's flow area, not the outside temp. So the reading you got this morning was probably about right for the temp that would be inline with the coolant system. Yes, the gauge is always reading. If you were to unscrew the gauge from it's block, you would find that it basically looks like the same thermometer that people use for cooking and are used on vehicles. The rod heats up and it moves the needle on the gauge. Hope this answers your question.

Pumashine · « **Reply #11 on:** April 24, 2014, 11:08:02 AM »

When guys say their 250r is overheating I am assuming there is coolant going through the overflow line into the over flow tank. Something you would want to fix. If your gauge is reading hot without loosing coolant it makes you wonder?

whats really going on?

Jerry Hall · « **Reply #12 on:** April 24, 2014, 11:52:32 AM »

Be careful using an infra-red gun to read temperatures of metal surfaces. The emissivities of different surfaces will fool the guns that do not have the ability to change the emissive sensitivity. The surface finish has an effect on the accuracy of the guns. If the surface is dull, sandblasted or painted the guns accuracy will usually be acceptable on most cheap IR guns. Chrome, polished or very smooth surfaces as the metal comes from the mill, will most often affect the accuracy of the guns that do not have the adjustment for different emissivities. The price of the IR guns that have the adjustment usually starts at about $200.00.

If I am trying to get a ballpark coolant temperature using an IR gun I hold it about an inch away from the back side of the radiator next to radiator where the coolant enters the radiator. If you have an aftermarket radiator that is bight or shinny aluminum, this procedure will not usually produce accurate results. If the cylinder or head has been polished the reading will not usually be accurate if the gun is aimed at the head or cylinder.

I have seen some guys using IR guns to try to read the exhaust temperature by aiming the guns at a chrome or stainless steel pipe while dyno testing. You will be fortunate to be within 100 to 200 deg. F of the actual temperature.

An inline temperature gage will measure the temperature of the coolant inside the coolant line. The coolant temperature inside the coolant line will be real close to the temperature of an enclosed garage after setting overnight. I have observed this many times with customer bikes in my shop. The temp.reading on the coolant temp. gage will always be within 5 degrees or so of the shop temp if they sit for a few hours after being run.

I see a lot of pressure caps that do not seal against the radiator cap flange. I remove the hoses from the radiator, plug one line and use an adaptor to apply air pressure that can be controlled to the other radiator hose inlet to the radiator. Place the coolant overflow line in a jar of water. Gradually increase the air pressure to the radiator and watch for bubbles in the jar of water. There should not be ANY bubbles until the air pressure reaches the rated pressure (plus or minus 1 lb or so) of the radiator cap rating. This test method test the pressure cap rating as well as the sealing surface of the radiator flange. Testing the cap on a radiator cap test rig WILL NOt tell you if your cap is sealing on YOUR radiator.

derekd7987 · « **Reply #13 on:** April 24, 2014, 12:22:06 PM »

thanks black, puma and jerry. i still have the stock overflow bottle on the back and when it was supposedly overheating i dont know if it was spitting water into the bottle or not. i didnt pay close attention to the fill level before i started so i dont know if it overflowed any in there. i will pay close attention to that today. hopefully i have time to mess with it today and ill report results back tonight or tomorrow. thanks for all the comments and help

derekd7987 · « **Reply #14 on:** April 25, 2014, 12:36:32 PM »

so yesterday i started it and let it warm up and went for a ride around the neighborhood and also let it rip a few good times on the road and on this short little trail. i stopped and let it idle in the middle of the ride for a few minutes and also let it idle awhile after riding before i started checking and comparing temps. the highest i saw it get yesterday by the gauge was about 195. when i was checking the IR thermometer the gauge was at about 185. with the gauge at about 185 the IR thermometer showed around 140 around the cylinder, around 185 on the head and about 165 on the block of the gauge and about everywhere else on the hoses. so what do yall think?

also i tried squeezing or putting a little pressure on the lower hose and revving it. it kinda felt like water was flowing through there but it didnt feel like it was trying to collapse or suck itself together.

i think i am just gonna have to go to my local spot and ride it like i would normally be riding it and watch the gauge and the overflow tank?