Garden Tractor Forums banner
1 - 20 of 25 Posts

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #1 ·
Alright guys, after having my MF12 for over a year now. I am tired of chasing after my idle speed and I don't think it is the carb. I even pulled the carb off last night and went through it and the only thing that I seen was the tiny holes on the service nozzle in the machined service area needed cleaned. I cleaned them up and I have the carb tuned great. At idle with the clutch out the idle speed is perfect. Press the clutch in and it ramps up in speed, I don't know how many rpm increase but it is substantial.

I wanna know if anyone else with a gear drive has this issue? Does your idle speed change depending on if the clutch is pressed or not? I understand why the idle speed would change so don't need that explanation LOL.

I guess what I am trying to find out is if I need to service the variable sheave or redo the adjustments so there is more of a freewheel when in neutral whether the clutch is in or out.
 

·
Elf guardian
Joined
·
7,712 Posts
I think you're barking up the right tree.
How are the belts looking? Any flat spots.
And if you set the idle with the clutch in, does it die when you engage the clutch?

edit
no, idle speed does not change dramatically whether clutch in or out.
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #3 ·
IamSherwood said:
I think you're barking up the right tree.
How are the belts looking? Any flat spots.
And if you set the idle with the clutch in, does it die when you engage the clutch?
I haven't set the idle with the clutch in but I can promise if I did it would stall. I also never put it in the park position on the variator.
 

·
Elf guardian
Joined
·
7,712 Posts
In this pic, you can see about 3 shims on the outside of the sheeve. When I put brand new MF belts
on, all the shims had to be inside the sheeve. Also, it's important to follow the adjustment proceedure
in the service manual. Ya can't just wing it.
 

Attachments

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #6 ·
I actually just moved a couple of shims when I did the detent springs in the tranny. Mainly because if I had the variator in 1st - 3rd you could really notice some slipping. So I adjusted the shims to try and help. I did try to follow the procedure in the service manual last year but I know something about it didn't make sense and I did "wing" it LOL. I will have to print the manual again and maybe try and adjust it tomorrow. I just hate coming to a stop and then the idle is really high like it is lean but it isn't until I let the clutch out with the tranny in neutral and then it sounds good.
 

·
Tractorholic
Joined
·
8,365 Posts
I would think that if the idle was set with the clutch in and the governor was set correctly as the clutch started to engage it would open the throttle to keep the same RPM . I think it might be worth a try to checking the governor settings , Al
 

·
Electric Tractors
Joined
·
5,639 Posts
When you put the vari-drive in park it's the same as holding the clutch down, the belts loosen right up.
As far as the idle changing when the clutch is pushed or not, when the vari-drive is in 1to5, all that changes is the belts tighten and loosen up as you know.
Is there any thing dragging, belt guide not right, double sheaves not turning freely, stiff tensioner, trany not turning freely?
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #11 ·
I don't think it is drag in the tranny. I think it might be the sheave. I noticed today when shutting it down it kind of made a knocking sound which was the clutch pedal hitting the foot plate on the last revolution of the engine at shut down.
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #12 ·
I am going to dig in to it tomorrow and will let yas know if I find anything. I am sure it needs proper adjustment anyway. I think my belts are still in decent shape.
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #13 ·
I was just going over the service manual and am I the only one that finds their instructions a little confusing? I am hoping though between the manual and Doug's post he linked to I should be able to figure it out.
 

·
Proud to be Deplorable
Joined
·
29,904 Posts
NUTNDUN said:
I was just going over the service manual and am I the only one that finds their instructions a little confusing? I am hoping though between the manual and Doug's post he linked to I should be able to figure it out.
I agree, the manual was written in Celtic, then translated by Tibettan Monks into English.

I think I know the sound you are talking about... Your tensioner pulley is either going bad or the belt/tensioner is hitting the underside of the tin. That would put a substantial drag on things if thats the case. Only q here is you should be hearing it all the time.

You should be able to set the idle with the clutch in and then the gov should compensate. If it doesn't respond fast enough, you may have a governor problem. If you pull another tractor with good brakes and have the second driver begin to engage them, you should hear the governor open things up. Even at low rpms, it should respond, may still stall, but it should respond.
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #15 ·
I know the governor works great. If I have it at idle speed and go to pull out even if fourth it kicks the rpms up. With the stack on it, it is more like a bark and very noticeable. I know the tension spring for the belt tension pulley was rusted up pretty good and didn't make for smooth movement of the pulley arm. I should probably pull it off and sandblast it and put a light coating of grease on it.
 

·
Member
Joined
·
129 Posts
I have something similar on my MF10. The well-worn starter-generator can't turn the engine over, even when the transmission is in neutral unless the variator is in park or the clutch is right down. It seems that once the front belt is engaged, the additional friction of the two pulleys is too much for the starter. I put it down to a combination of a worn tensioner system which I know needs to have it's rivets replaced and an idler pulley that is not running as straight as it should- there is too much wear in the bushing and pivot where the idler carrier pivots on the transaxle. Once it's running the engine doesn't much notice whether the clutch is in or out - it has that much more torque than the s/g I guess. It sounds like too much friction at the back end. It might be good to check the rear idler bearing.

George
 

·
Tractorholic
Joined
·
8,365 Posts
:rolling::rolling:
Check to see if the idler is rubbing on the bottom of the tinwork. The manual says something about "Below the frame" for positioning... read it twice & then guess at what they mean... :D
Funny but true the way most instruction read.
 

·
Premium Member
Joined
·
15,923 Posts
Discussion Starter · #19 ·
I am happy to report that I got everything adjusted and it is working like a champ. I did the variable adjustment per the manual and also adjusted the brake, I now have all five speeds instantly and my parking brake works now LOL.

I also noticed that the load on the engine was almost non existent while the variable lever was in a drive position but the tranny in neutral. I readjusted the carb once the engine was at full temp and I adjusted it while it was in park. She idles great now and it doesn't matter if it is in neutral by either park or gear shift. It is a shame she burns a little oil, has been doing that since I got it. Will probably try and redo the rings sometime soon unless I put a China diesel in it.

I took a quick video and will post it a little later once it is uploaded.
 

·
Electric Tractors
Joined
·
5,639 Posts
Good stuff George
The vari-drive adjustment is really not hard to do but you have to do it the way they say and in the order they say or it just won't work right.
 
1 - 20 of 25 Posts
Top