Mower Blade Engagement Problem on a Riding Mower

I just got this mower back from my brother who I sold it to 2 years ago. He let it sit and was going to take it to the junkyard. It was bought in 2002. It has less than 75 hours on it.

Anyway I got it running.

Problem one is that it is Hunting a little bit. "How do I fix it?

Problem Two. When I go to engage the mower blad the engine dies. I Pulled out the whole mower shaft because it was hard to turn and I figured the bearings were tight. Lubed them up and all is well. Still will not engage.
I think that when you engage the blades it should speed up to compensate for the entra load. But it is not doing it. Its just killing the engine. Is there anything Im missing? Im trying to sell this thing to my Boss but want it running good.

 

If you can describe my car maybe I can help you with your mower. Here is more of a hint than you provided...my car is red

 

That is the round about way of telling you we need more info. Make, Model# Engine# to be able to help you.

Chances are you have an electrical issue which could be as simple as dirty contacts or a bad safety switch. All riders are different but all have safeties that will kill the engine under certain circumstances.

Such as, there is a seat switch that if not working (or you are not seated in the seat) will kill the engine when you engage the blade. See where I am going with this?

Get us some info and I am sure you will get some answers.

 

There are so many types of PTO or Mower Deck engagements within one manufacturer let alone all the different ones. Each type has its common and uncommon problems and issues.
Can you imagine the time one might spend covering all of them with an explanation when you only need one...., and all supplied still may not apply to yours.........

Same with the hunting, its likely a fuel issue but again so many fuel systems and carb types.....

 

Thanks for the decent response small engine guy. Here is what I have.

A White Outdoor LR927
9 HP Briggs and Stratton
Model # 13a-328-190
Bag Catcher is under the seat.

And for AZIS its color is Red and Grey.

 

Oh the red and gray one, well here is a link for an Owners Manual your boss may appreciate. http://manuals.mtdproducts.com/mtd/DocGetter?doc=770-10062c.pdf

Does engaging the pedal for the PTO lug the engine down, or does it just die like turning off the key?
If it lugs the engine down, then you need to make sure you can spin the spindle and idler pulleys by pulling the belt by hand. You should be able to slip it around the engine pulley enough with the blade pedal disengaged. Pull the belt up tight so the slack is around the engine pulley and try to spin the blade spindle and idler pulleys.
If it dies like turning off the key, then its likely a safety switch and may require a meter to test which.

 

I believe it is a switch. All the pulleys move smoothly. I have a fluke but what do I test? I have the switch under the seat disconnected and the wires are tighted together to bypass the switch. What other switch can it be?

 

The seat switch is has a shunt in the circuit that must be satisfied in order for the rest of the circuit to be happy. Make sure the connections are good, the pins inside the amp connectors will sometimes spread, push out of the lock etc. and if connection is lost will not work. Otherwise a new seat switch will be needed. You might check the PTO switch for continuity, without a diagram or schematic I am not sure how your circuit is wired. I think on your mower, which btw is somewhat unique at least in my parts, do you have to have the parking brake engaged to get off the mower while the engine is running and the PTO is Dis-engaged?
I don't know if your "go" pedal eliminated this switch or not. But if with the parking brake disengaged and the PTO disengaged, you lift off the seat and it dies, then its the seat switch.

 

The seat switch is bypassed. and has been since I bought it new. When I start it you dont need to be on the seat at all. It runs fine. You need the brak to start the engine that is all. There are two circuit looking switches that are wired into the start circuit. Could one of them be for the PTO? they are the same and Ive switched them back and forth and no luck.

 

If you need the brake on to start it then the problem is still the seat switch. The PTO and clutch/brake are wired into the starting circuit, and the PTO and seat switch the kill circuit. The brake lets the starting circuit know its ok if the seat is not occupied.

 

I am not sure when MTD started using the "shunted" circuit but I thought they had by 2002 which is when you stated you bought it new.
I can't honestly say I know what happens when the PTO switch fails, as long as all other conditions are met, it shouldnt matter if the switch itself actuates or not.

 

I switched those two micro switches around. Now the PTO engages but when I let off the break the engine dies. Here is the part # on the switch
Its made by Hella
4rd 931 524 02

Know where to get one?

 

If you look at the url I posted for the Owners Manual, you will find a parts list in the back. The correct MTD part # replacement will be listed there, should be a 7??-???? or 9??-????
Any local dealer who sells or services MTD or White products should have the parts.

 

You might also check those switches you swapped, see if one is normally open and one normally closed, if so they may both still be doing just what they should.

 

Regards to your wife btw,
I would like to suggest for way TOO many reasons to post, that you replace the seat switch and any other faulty one you may find, but that you leave the safety devices intact.

 

both switches have the same part number on them. they should be the same.

 

Good Luck!...........

 

Here is a link to your electrical:

http://mtd.arinet.com/scripts/EmpartISAPI.dll?MF&app=MTDC&session=a53ad183-6546-4bbb-950d-8b5d7f5f48ce&cat=22&bss=&TF=FrameSet&cat=22&assem=1389&ignoreHist=Yes

I would pull wires out of connectors and clean with sandpaper or a wire brush on a drill. I just had a Craftsman and a Toro and cleaning all connections solved problems. Try the simple things 1st.

As far as your surging, fresh (from the pump) fuel, carb cleaning (rebuild kit), new air filter - should solve your problem