Suzuki DT 25 overheating

[fishheadmi]

My Suzuki DT 25 (~'82) is overheating. The water pump is working when engine is cool, but stops after about a 3 minute run. The engine gets very overheated. <br /><br />I checked the thermostat in boiling water (it opens at about 145-150 deg.). I pulled the thermostat out while on the water yesterday (stranded) and ran the engine without it and it still overheated after about 3 minutes.<br /><br />I've inspected the water pump impeller and it is in good shape. Although I can't get the flush valve unscrewed (frozen), I did pour water down from where the thermostat is located and water came out of the tube that connects to the water pump. I also flushed out everything else (intake, etc.). I'm at a loss and hunting season starts next weekend.

 

[plywoody]

Re: Suzuki DT 25 overheating

I'm confused. Did you say the water pump stops pumping when the engine warms up?<br />I am not sure how you determined whether the impeller and water pump was ok, but I'd check it again, and perhaps change it just in case. From there, check all tube connections and rubber grommets from the pump to the powerhead to make sure they are all in place and seated properly.<br /><br />From there, I'd remove the powerhead and make sure there was no buildup of salt/sand or other foreign substance that would limit water flow in the cooling jackets.<br /><br />The cooling systems of these motors is not all that complex, or all that mysterious. If it is not cooling, it must not be getting water somewhere, and there is always a reason why. You have to start at one end and go toward the other until you find the problem.<br /><br />Unless the water pump has been replaced recently, though, I think I would change it just to be sure. Sometimes they are worn and it is difficult to tell whether they will work properly simply by inspection.<br /><br />John

 

[fishheadmi]

Re: Suzuki DT 25 overheating

Thanks for the input. I removed and inspected the impeller and it looked okay, but I'll change it anyway just to be safe. I'll remove the powerhead next. I bet the clog is in there. Any ideas on how to remove the bolts that hold it on? I tried to remove one and it broke.

 

[digimortal777]

Re: Suzuki DT 25 overheating

i dont want to look......

 

[plywoody]

Re: Suzuki DT 25 overheating

Are the bolts on the powerhead all corroded? They are typically not torqued down all that tight (18 ft/lbs or so)<br />Don't know what to say about taking the bolts out, except that if they are in that bad a shape, you'll probably be better off having a qualified shop do it, with access to a machine shop.<br /><br />John

 

[cgrivois]

Re: Suzuki DT 25 overheating

Ive got the same problem with my 93 dt25. when water come out tell tail hole it very little, then stops. Ive replace water pump impeller, wear plate, gasget, but not housing. ive also replace thermostat, and exhaust cover gasgets. no debree in or aound cylenders to prevent water. pick up tube apears to be broken at very bottom, that is my next try. any info you find out, please let me know. seems we have the same symptoms.<br />Craig<br />Columbia SC.

 

[cgrivois]

Re: Suzuki DT 25 overheating

it appears that Ive got mine fixed. I replaced exhaust gaskets, head cover gasket, and oil seal housing gasket, but what I think did the trick was I put a gasket sealer between the pump housing, and the wear plate. Not sure if this will leed to something bad in the future, but it seems to draw plenty of water with the muffs on. Seems to work so far, so Ill go with it. Hope this helps.<br /><br />Craig <br />Columbia SC