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'78 GT18 seems slow. Normal?

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35 replies to this topic

#31 craftsmanmowerfreak OFFLINE  

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Posted October 27, 2015 - 04:19 PM

I just checked and my tires are 23x10.00-12 (pretty sure stock tires). here is a close-up of my pulley system. Looks normal to me.



ur deck belt is on wrong pulley its supposed to be on the big pulley

#32 craftsmanmowerfreak OFFLINE  

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Posted October 27, 2015 - 04:27 PM

heres copy of a page out of a ss/14 manual. rotary mower big pulley

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#33 wahoowad OFFLINE  

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Posted October 27, 2015 - 06:23 PM

Ignore the deck/sickle mower belt. I don't use it anymore. I'm only asking about the main drive belt. It appears to be on the right pulley.


Still at a loss why this things moves so slow even in high/3 gear.


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Posted October 28, 2015 - 08:26 AM

Your main drive belt should be on the inner most groove which appears to be what you have.

#35 Tecumseh power OFFLINE  

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Posted November 14, 2015 - 11:49 PM

I have a 78 gt 18 and an 84 gt 18. Both are pretty slow in 3h. To help you understand how slow to do my yard with one of my gt tractors it takes me 3 hours. To do my yard with my regular mtd lawn tractor it takes me an hour and 15 min. They aren't fast by any means .

#36 JiminRI OFFLINE  

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Posted December 07, 2015 - 09:14 PM

At this point I'll have to get it running up on my neighborhood street and see if my little handheld GPS gizmo will show me the ground speed.


I know my trans is still low on fluid as I changed it recently and never filled it up all the way. I tried but it was so darn slow to fill that I ran out of patience. I think i stopped after 3 quarts of SAE 30 as I knew i was close (think it calls for 3.5 quarts?) and I am not using the tractor for anything yet so didn't figure there would be any heat buildup. I added another 1/2 quart this weekend which was still very slow to fill even after I removed a shifter bolt to let air escape. The cold SAE 30 didn't help - it poured like molasses. I can't see this being responsible for the slowness though since I know I have a good bit of fluid in there.

You don't need a GPS. Mark of a measured range, say 95 feet to make it easy, and measure the time at top speed. Top speed of about 6.5 MPH is about 9.5 feet per second so the 95 feet would take 10 seconds. If you measure 20 seconds (twice as long) then you were travelling half the speed (6.5 mph/2= 3.75 mph).Your speed would be 6.5/(your measured time)*10 or 65/(your measured time).