# MTD yard bug won't move when gas pressed



## quattroginger

I was given a free yard machine. I know the PO and he said he just put new belts on. I replaced front tired and 1 of the 2 throttle cables. Forward and reverse handle work but when I hit gas pedal it doesn't go anywhere. 

Ideas? Thanks


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## farmertim

Welcome to the forum quattroginger!!
sounds like the belts aren't routed properly, can you post the model and year and someone should be able to help.
Cheers


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## pogobill

Did it work before you changed the throttle cable?


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## quattroginger

He said it worked up to the day he gave it to me. I had it for 2 seasons without using because I thought it needed belts. Then found out he had replaced them before giving to me. So all it needed was front tires since no tread was left. Here is pic of model 

I had another mower to use so never really pushed to use it till this season. I think the cable froze because of sitting in my garage so long without use.


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## quattroginger

I see both forward and reverse cable move in and out directly above the rear of the deck. When I push gas pedal there is very little pressure if any and I hear a spring stretching somewhere under the motor


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## pogobill

If you don't have a manual for it, I put one here for you.

http://www.tractorforum.com/manuals/yardman-model-13b-325-401-32.html

Cheers
Bill


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## quattroginger

Thank you. I do have one printed out. I'm just not to familiar with riders. This is first one I've ever owned. Other than the basics of checking that everything is connected not sure what else to look at


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## jhngardner367

Welcome to the forum !
The Yard Bug doesn't have a "gas pedal". It has a brake pedal,and a VARIABLE SPEED pedal.
The variable speed pedal moves a sliding-sheave pulley,to loosen ,or tighten the belt.If the center sheave of the pulley is rusty/stuck,and can't slide up/down,it won't drive the wheels.


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## quattroginger

so i talked to the PO again few minutes ago. he only replaced the deck belt. is there any chance that the rear belt just has gone bad? From what i was explained at Tractor Supply, if the belt is to narrow it wont seat properly on the pulley. i guess first thing i need to do is tip this bad boy on its side, have someone hit the pedal and see if i can see the sliding sheave pulley move in the rear.


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## jhngardner367

Tipping it on its side may flood the engine with oil. Try putting the front wheels up on blocks/ramps,instead.
The sliding pulley sheave only slides up,or down,with the unit runnig,but you can check to see if the belt is loose .It should have tension on it,even when not running.


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## stickerpicker

In general, for a belt to prevent any movement it has to look really bad and often smells worse. One exception is the variable speed system with 2 belts that work in conjunction with each other, but still they need to appear as if the pup used them for a teething ring.

Slacken or remove both drive belts from the variable sheave and check sheave operation as jhngardner367 mentioned. The center portion should move with finger pressure.


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## quattroginger

i will check the up/down of the rear belt's sheave pulley. the deck belt functions as it should. the sheave pulley moves left to right tightening the belt and engaging the blades. 


EDIT: now that i look more at pages 16&17 of manual above i understand that both drive belts are the variable speed belts. however i don't understand which pulley would be moving up and down. Can someone please point this out for me. thanks again for all the help.


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## stickerpicker

quattroginger said:


> i will check the up/down of the rear belt's sheave pulley. the deck belt functions as it should. the sheave pulley moves left to right tightening the belt and engaging the blades.
> 
> 
> EDIT: now that i look more at pages 16&17 of manual above i understand that both drive belts are the variable speed belts. however i don't understand which pulley would be moving up and down. Can someone please point this out for me. thanks again for all the help.


The variable pulley will look like this one pictured or similar. In the picture the mid section is as low as it will go by gravity. Turn that pulley system over and the mid section will fall to the opposite side by gravity alone.

It has 2 belts and 2 V grooves. With the belts removed or completely slack the mid section of yours should move easily.

While here allow me to X-plain how it works. Each of the 2 drive ( motion ) belts will have a spring tensioned idler pulley. One will have fixed tension and the other will have variable tension chosen by the operator. Your speed selector control does this and is to be moved when the tractor is in motion with no clutch depression. 

When changing travel speeds the relationship between the two idler assemblies spring tensions is altered and the mid section of the variable pulley adjusts to conform to that change the operator made.

None of this has any correlation to the belt that drives the blades.


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## quattroginger

Thinking this might of been my problem lol. No idea how I didn't see this before


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## jhngardner367

Yeah, that would definitely do it ! LOL !


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## veeguy

Don't waste money replacing that belt... A daub or two of belt dressing and it'll be good as new.


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## quattroginger

Exactly what I was thinking. Gorilla glue should fix this


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## quattroginger

Ok got my belts in, how to I hold engine pulley in place to loosen bolt?








When I turn it it just turns whole pulley


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## quattroginger

Ok got that with vise grips. Now when I engage blades it starts smoking because it's eating belt. Not sure why other than this spring isn't hooked up to anything








My guess is the spring was once longer and connected to that empty hole?


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## Tanner

First time here,
I have a MTD Yard Bug green and yellow. Today after mowing our 1/4 acre I was just about done and the Gas pedal felt like it was bouncing under my shoe. I stopped it and manually pressed the pedal up and down it looked like it was OK. I got back on started it up, pressed the pedal to the floor and it completely stopped. Engine was running but the gas pedal had No go in it. What do you think ?


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## gman51

For the belt smoking rotate the blades by hand to see if they move freely. If they don't move freely it could be the pulley shaft bearings are rusted tight.
Tanner I am guessing your main drive belt just busted.


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## BigT

Hello Tanner, welcome to the forum.

You probably broke the same belt as disclosed in the original post.


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