721DH2 running hot need help!

[alford35]

OK, turned mower on, waited a while. Looked to be flow inside the radiator. The radiator hose seemed fine, it wasnt collapsed on itself. The coolant overflow on the other hand has nothing in it.

Ok, found one problem so now what?

Thanks guys

 

[alford35]

I've looked at the manual and dont understand how to fill the overflow. And, it also says two different things. One, mix 50-50 antifreeze water and two top off with only water.

It may be that I have to take off the engine housing to get to it?

 

[173abn]

alex,unfortunally I believe thats the only way to put fluid in there,there should be a mark on the tank to fill it to.I would go with the 50-50 mix.let us know what happens ..russ

 

[alford35]

Ok. That's what I was affraid of. Oh well, only about 10 bolts I would guess. Will fill tomorrow. Need to see what color antifreeze is and match it.

 

[thehemikid]

Not much help but fwiw,...I've mowed with my 721D now for a little less than 2 months with no fluid in the overflow tank at all. I noticed it after my first mow, but didn't think to much about it cause the gauge was ~ 3/4's the way up in the white, so I didn't bother with it yet. Then one day I was bush hogging a hillside with it, working the trany's more than usual with the hill side & tall weeds. The wind was blowing the chaff back on me & the mower. The temp was about 1/4 the way up into the green when I finished. I thought it was going to be the "less fluid" but it appears to me, that it ended up being more chaff than usual in the screen & radiator than my normal mowing. So I've yet to fill the overflow tank.

 

[ekim22]

I've had my grasshopper for 1 summer now and I'll say that this mower is the most sensitive to overheating I have ever seen. I have to constantly stop and clean the vent over the radiator every 30 minutes or when the needle hits the red mark. It seems like poor engineering to me having the intake vent into the radiator being where it is. Also have to be sure to keep high levels of water/coolant in the radiator.

 

[alford35]

OK, update

I did everything that was suggested. I topped off coolant, blew radiator out from both front and back, and checked for any pump problems.

Well after blowing the radiator out really good it helped a lot but didnt stop the mower from reaching the hot limit. It now takes atleast 3-4 times as long for it to get hot.

I agree about the clippings piling up on both the radiator and the screen very quickly. There is no way the motor will ever run at its optimal temp with the clipping covering its airway within a few short minutes.

I have searched through my two manuals and cant find the thermostat location. I looked over each manual like 4 different times thinking I was over looking it but I believe that it isnt in the exploded diagram and nowhere in the other manual either. Could someone link me to its location or just take a picture of it for me please? It shouldnt be hard to change should it? I will be the first to tell you that I'm not very mechanically inclined although I have the tools and manage to get the job done if it is rather straight forward.

I was thinking that changing the thrmostat and the radiator cap should be my next steps? Does that sound right?

Thanks everyone. Its not as bad as it was but there is still a problem unless it is truly the design flaw of where the radiator is located. This last time I mowed for about an hour before the light came on and had to desengage the blades for it to cool down.

 

[173abn]

If you have a thermostat it should be located at the upper rad hose where it goes to the water pump.That said I'm going out on a limb and will say it proably does'nt have one.My 928d and my Yanmar tractor don't have one.If you can't find it in the manuel then it does not have one...russ

 

[alford35]

OK, if it doesnt have a thermostat then what should my next move be? I'm gonna pick up a radiator cap for sure but then what?

Maybe have the radiator proffesionally cleaned out?

I really have no idea. If it ends up being that I need to do something serious then I will just go and drop it off at the Grasshopper dealer where we bought it and tell him to either keep it or bring it to my house when it is working correctly.

I may sound kind of like a jack ***** but the wife and I had been talking to the owner about buying the shop from him since he is ready to retire before we bought this mower from him. When I took it back the first time he acted really nice and said yeah no problem I'll get it figured out for you. Then the second time it was like he wasnt happy to see me back in there. Thats when I told him that if there is something wrong I'll just pay the cash difference for a brand new one. He was persistant that it was just something small and needed to be found that there is nothing wrong with the unit.

Its now starting to really get to me being that he and his family are patients of my wife and now itseems as if my service has been less than adequate. I've now done more trouble shooting than he has for this mower that he claims has nothing wrong with it, that its just a matter of finding it. He claims that he doesnt have the grass to mow and test it out after the changes he makes. Once someone spends over $9000 on a mower from you and excuses like that are your reasoning for not knowing if its fixed or not, things have to change.

Sorry for the rant guys but this type of stuff is what I deal with in my line of work so when its done to me personally on a somewhat mutual deal then it really gets to me. I turn laborers and subcontractors away on a daily basis just because I dont deal with people that take what they can get if they can get away with it, if you know what I mean.

 

[173abn]

alford35,if it were my mower I'd take it back and tell him to fix it or get your money back.It sounds to me he knew it had a problem before he sold it to you.My Yanmar tractor would overheat so I replaced the head gasket but I figured that while I had it tore down I would get the injectors tested,I took them to a diesel shop along with the head.They found one bad injector was dumping too much fuel causing it to overheat and also had bent the intake valve.I had them test the head for warpage and rebuid the head and all 3 injectors.That was three yrs. ago and haven'nt had no problems since.I 'm sorry I can't be any more help and wish someone here could give you better info.When I mow w/my 928d the screen gets really covered w/chaff but rarely gets even to the green mark.Please keep us updated on what you decide to do .I for one would really like to know what your problem turns out to be...russ