Water Pump Question

[doakley]

Searched and found a lot on replacing pump seals. My question is how do you know if your water pump is pumping correctly? Or—Is it possible mynoverheating problem has nothing to do with the autoclutch but my pump is worn and not pumping adequately? Just reaching for a solution here and appreciate help.

[kdxdazz]

My bike when I bought it was overheating terribly, I took the cap off took a look inside and could see the cores were blocked, I had to cut the bottom tanks off then feed a hacksaw blade down every core

[6 Riders]

What year is your bike?
It never hurts to do maintenance!

[doakley]

Bike is not short on maintenance. Just trying to look for reasons other than the autoclutch.

[bufftester]

Short of installing a flow meter I usually take the cap off the radiator and start the bike. You should see bubbling and fluid movement. If you suspect a pump issue ensure the impeller is not spinning on the pump shaft and that none of the vanes are damaged. One video I saw a while back guy thought he had a blockage so hooked up a garden hose to the hose coming out of the pump and made sure he had flow coming out with the hose on. Not sure how good a check that is tho...

[doakley]

Ok, more info. The bike is a 99 220 but the radiators are 2 yrs old, Chinese aftermarket. (Tore up the OEM’s in a race)
-never had a problem overheating until I installed the EFM autoclutch.
-took the cover off the water pump today. All looks good to me, no broken vanes, case is not scored, impeller turns with the engine without slipping, no free play.
-changed rad cap to 1.6 psi model, running 50/50 antifreeze/water. Seems to be ok in open stuff but gets hot in tight single track. I suspect reduced air flow due to slower speeds and lots of clutch slipping.
- I’m going to crank it with the water pump hose off and see how strong the pump is.

[KDXGarage]

Do you have the reserve tank?

by the way, BEST ANSWER on what happened to the stock radiators!

[doakley]

Haha, yeah, well, I tore up both radiators in the Sandlapper enduro a couple of years ago. Seems I just had a love/hate relationship with trees!
Yes, I have the reserve tank. At the Sumter enduro it boiled out the majority of the coolant and it overflowed out the overflow hose for the reserve tank. Confirmed this morning the water pump seems to be doing its thing. At least if you pop off the bleed screw on top of the cylinder it spews coolant out in an increasing amount with engine rpm. I don't think it is the pump.

My plan right now is to fill it with Engine Ice when that comes in this week then ride it in the Eagles Nest enduro Sunday. If it still overheats, I'm going to pull the autoclutch out and send it to EFM just to make sure it is working correctly, since I did buy it used and am the 3rd owner. Depending on what Gary at EFM tells me, I may just go back to the manual clutch and foot brake.

[bufftester]

Your clutch would have to really be generating a crap ton of heat to overheat the bike as the cooling system is independent of the sump portion of the engine. When was the last time you checked your jetting for a lean condition? It may also be the replacement radiators just not flowing enough, some folks have had varying success with them.

[6 Riders]

Could be a leaking seal. Is your transmission oil turning funky colors?
You could try different oils as well, such as ATF, just a better brand etc.

[doakley]

No water in the oil (ATF).
Haven’t changed the jetting in over a year of racing. Sounds like it might be a good idea to just switch back to the manual clutch and see if the overheating problem just goes away since it didn’t start until I installed the autoclutch. Unfortunately I don’t have time to switch them out before I leave for the FL enduro on Saturday.

[doakley]

BTW, I really appreciate everyone’s feedback and suggestions.

[KDXGarage]

Something is not right, as many people have raced enduros and hare scrambles with KDX's and not had it boil all the time.

Which coolant / water / etc. solution have you been using?

[Molly's 70]

From what I have read, it seems like things went south after the Chinese radiator install. I'd just give the whole cooling system a though check including a new radiator cap & factory radiators. Ouch!

[doakley]

Anybody have a preferred vendor for OEM radiators?

[KDXGarage]

eBay used ??