Overheating help please

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ihatefalling
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Overheating help please

Post by ihatefalling »

Hey guys, took the old girl out for it's first woods ride in months yesterday...man it felt good!

However....for some reason it overheated and was spewing steam from the hose down by the rear brake pedal.......it did so at a place that I would never expect it too ???

Maybe I was paranoid, but ti seemed to be running a little hot all day. The outside temps were fine so I would have never thought it would run hot.

I've read a few threads about replacing the radiator cap but what about this....

I put new reeds in it before the ride. I didn't adjust the jetting tho. Think that has domething to do with it? I'm NOT a jetting expert at all.
Last edited by ihatefalling on 10:09 am Sep 27 2010, edited 1 time in total.
2005 KDX 220
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gregp
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Post by gregp »

The RB head mod should not make your 220 overheat. You mentioned that you had installed new reeds - make sure you do not have an air leak around the reed cage. You do not mention that your bike "felt lean" at all (some signs would be: bogging throttle, high idle that does not want to come down, extremely "revvy" feeling motor - and, running hot).
Some things to check - your pre-mix (make sure you have enough oil in it), the water pump/impeller/seal, the head gasket, and the radiator cap (make sure it is fully and correctly seated).
The KDX200/220's are very reliable bikes, and should not overheat easily. You can add some Water Wetter, or another coolant additive if you do not find something obviously wrong. These items work, and can take 10 degrees off of your operating temperature fairly easily.
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NewMexico505
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Post by NewMexico505 »

One of your radiator's can be slightly smashed, by looking at it, the radiator may look ok but possibly its not flowing any or enough water through.

Thats what happened to mine...looked ok, poor flow of coolant, overheated up the slightest incline at slow trail speeds.
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ihatefalling
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Post by ihatefalling »

Thanks for the input guys. Went out tonight, let the motor warm up good, and then sprayed WD40 around the reed block and carb boots to see if it would affect the idle. It didn't. I don't know if that's an actual test that will proove anything though.

One thing I did notice was....when the bike was leaning on the stand it would idle at a regular speed, then if I stood it straight up the idle would pick up some.....lean it back over and the idle would come back down.

The bike did seem a little "boggy" this weekend.....didn't hit like it normally does.

The gas is a few months old probably. Ratio should be good. Amsoil Intimidator 50:1

Radiator, seals...all looked good. No signs of leaks.
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Post by Mr. Wibbens »

Check your water pump seal

Mine was overheating last year about this time, I figured I was running to lean so I jetted accordingly

On my next good ride the seal finally let loose and I nearly had a meltdown

Take the rad cap off while the bike is running (not when it's already hot) and see if it is all bubbly
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ihatefalling
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Post by ihatefalling »

Hey guys...thanks for the ideas. Sorry, I flaked out for a few days.

OK, here's an update. BTW, I replaced the reeds with Boysen Power Reeds. Bike has the RB carb and head mods....if that matters.

To try and fix a possible airleak, I took the carb out, cleaned the reed cage mating surfaces real good and applied a thin layer of Permatex exhaust gasket to the surfaces. Put it all back together.

While I had it apart, I noticed that the white "intake" plastic in the reed cage is offset to one side....meaning the reed cage definitly has a correct and upsidedown way of installing. Maybe I had installed it upside down when I changed the reeds last week?? Maybe that's why it was running hot??

BTW, I checked the radiator, it was low, it needed about 12 oz of coolant.

Anyways...started the bike back up and it was idliling high....higher than it was before the reed change. I turned the idle screw down....it idled nice and smooth. Took it for a short ride in a field. Once I got out in the open and gagged on the gas, the bike would bog out at about half way up the revs. It did this for about 5 gags in a row. Then I did some slow, low rpm hill climbs to try and build the heat up to see if it would overheat. It didn't. Then after a few minutes....when I gagged on it, the bog went away and it reved up normally. Weird.

So:

Perhaps I had put the reed cage in upside down when I changed the reeds?? Perhaps the exhaust gasket material helped seal a leak?? Perhaps reinstalling the carb in the boots fixed a leak??

But then why would the bike idle so much higher than it did before?
And why would it bog out half way through the revs??
But then the bog stopped??
2005 KDX 220
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Fork Swap - 99 KX125 Valved for B woods plush
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Post by heckler »

did you bleed the air out of your coolant system? that was my mistake on the weekend after if overheated - I just poured water in since we were on the trail, but I'm sure I had an airblock, because it just kept overheating.


The air bleed is on the top of the head, where the coolant hose goes into the head. Crack it and let the air come out until coolant comes out, then top up the coolant.


My idle was way up as well when I was low on coolant.
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ihatefalling
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Post by ihatefalling »

Good call.....thanks :cool:
2005 KDX 220
R&B Carb Mod
R&B Head Mod
Fork Swap - 99 KX125 Valved for B woods plush
FMF Gnarley
Airbox Mod
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