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Replaced secondary drive belt--now variator not working

2242 Views 17 Replies 11 Participants Last post by  kirk_lorenz
I have a 445 that the engine stalls on. It has just short of 1000 Hrs on it. When I mow after an hour or so it starts to stall every once in a while. Then as you continue mowing it gets worse. Sometimes if I shut off the engine and let the key run the fuel pump a couple of times I can then start it back up and mow for a longer period of time before it acts up again. After a while that doesn't work either. This spring I replaced the fuel filter as regular maintenance. I have removed the fuel pump and checked the suction screen and replaced the short pickup fuel hose on the pump. The old hose looked good though. Some things I have noticed. I don't get any codes, the pto never shuts off, the dash never flickers or quits working. The lights keep working. The red and green LED lights stay lit also. At one time I could get it to act up without the mower engaged so I removed the air filter to try and see if I am loosing fuel. I could see a small amount on top of the throttle plate until it died and then it didn't have any. When it died I could hear the electric pump running until it developed enough pressure to shut off. I removed the return fuel hose and on the plastic "T" and when it was running there was some fuel sputtering out of it. Not much but some. After it died then no fuel came out of it. What I don't know is if the electronics are shutting off the injector or if I am not getting fuel to the injector. When it starts back up and runs I have plenty of power until it acts up again. For the first hour or so I have plenty of power also. Any ideas? Thanks.
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Jed -

Check the wires going to your MAP sensor . The 445 is notorious for those wires getting chaf'ed and causing intermitent problems , and while you are at it check the vacuum hose to MAP also . This little thing is a big deal on the F-I Kaw , and very easy to get to . Sitting on seat it is attached to the lower left/rear of air filter base bracket . Might not be your problem .., but worth a look any-who .

Jed, are you using ethanol? This fuel causes these symptoms on many mowers we've encountered, it vapor locks with engine heat around fuel supply lines. Believe me, it has made my shop money...p--- poor product.
I replaced secondary drive belt on my 210 and now the variator doesn't want to work correctly. Old belt was getting cracked but not really worn down. Variator worked perfectly before changing belt. I installed a John Deere belt. Very easy to change. To get tractor to speed up and keep it there, I have to put my foot under pedal and hold it up. Primary belt looks fine. I did adjust the spring pressure on what pulls the variator assembly back. No change. Anyone else ever had this happen?

I had the exact thing happen this fall. I replaced the primary and secondary belt and it seemed worse than before. I checked and lubed the pivot bolt. No change. I lubricated variator with dry graphite. No change. I adjusted the variator spring. No Change. I adjusted the variator per the manual. No change. I still had to pull the clutch up with my boot to get the tractor to speed up. Finally I replaced the variator and idler springs at the same time readjusted variator spring and variator and Whala! My tractor has speed control on all 5 variator positions and the clutch pedal jumps all the way now. I can climb hills without slowing down like I used to!

Make sure your variator is moving freely and lubricate with dry graphite as needed! Good luck.

Thanks Hector.

Since I do not have a manual for tractor, how does one adjust the variator?

Just makes absolutely no sense why everything worked great before the simple belt change...
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Yes. 100% normal. The sides of said belt are worn some. The belt was stretched some. now it is not. Perfect sense.

Here is the page you need. In Step 4, when it says push down to take up slack Push your socket towards the ground. That bolt rides in a slot.

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Kirk , hopefully adjusting is all you need . I will say , though , the old-timers here advise replacing both drive belts at the same time . They are wear parts & MY experience is they have significant wear after 5 or 6 years .
Variators are tricky things. My 1974 112 had trouble pulling an empty trailer up a hill from my dumping grounds in 4th gear. The clutch pedal would go down and the tractor would move slowly unless you pulled the pedal back. I replaced both belts (JD) - no change. Replaced the variator spring - no change. Replaced the variator hub and one pulley - no change. De-carboned the head and replaced both valves and head gasket, and now it walks that trailer up the hill in 4th gear, half throttle, and the clutch pedal stays at full speed. GO FIGURE!
Thanks for the manuals! They sure will come in handy.

I now plan on doing it right by also replacing the primary belt and then adjust the variator according to the manual.
A weak engine that is not operating at the correct rpm can make a variator seem to not work properly. They need the correct belt speed [rpm] to achieve good operation. Belts should be changed at same time to get even grip on variator sheeves.
I installed the new primary belt today. Adjusted the variator according to the manual. Variator now works in the full range again. Still wants to slow down when going up hills in higher gears. I adjusted the variator spring according to the manual, which made no difference. Going to grease the pivot bolt and try the dry graphite next.

Any other things I should do or try?
Spring may be worn. Also, and I'm sure you know this, use JD belts. Aftermarket aren't made to fit as well as JD belts.
When the hub and the bushing inside the center sheave wear, this allows the center sheave to tilt to the side and create a pinch point, thus the sheave will not move freely.Yes, it will move freely by hand but that has nothing to do with the operation.

I haven't yet figured out why but they will speed up on the flat but slow down when there is a load. Anyway, that is my experience with my two tractors. Replacing the worn out variator solves the problem.

And yeah, I tried adjusting that spring six ways to Sunday with no effect. Even replaced it.
Kirk variators are designed to gear down the tractor when when under load condition such as going up hill. The reason for this is JD wanted the engine RPMs to remain near constant. The reason for that was all the engine powered attachments were designed to work best at the engines WOT position. What you are experiencing is normal. Sorry for preaching this to the others that have heard it from me before. Tightening the spring should have made some difference and if it didn't you may want to replace it. Old springs do become weaker with time. Roger
I installed John Deere belts. I wouldn't even think of using aftermarket belts. My son broke the mower deck belt on his L series John Deere after 400 hours. He put on an aftermarket belt thinking he would save some $$. Belt lasted 4 hours.... He then put on a John Deere belt (which only cost $2 more than the aftermarket) and has put over 100 hours on it thus far. Can you believe a L-series hydro with 500+ hours on it? And the only thing to go wrong with it is the mower deck drive belt....and a battery? And let's just say it hasn't had the best of treatment mowing 5 rough, crappy yards for people in our hood!

Anyway, Thanks to all for the help and advice on my variator and drive belts issues.
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