60" Deck question...

[Chat6155 3]

Greetings all.   Newbe to the forum, but bought my 312H new in 1990.  

 

Just upgraded from a 42" RD to a 60" deck.   When I first engaged the PTO, all was well except for a 'ticking' coming from the right side of the deck.   Removed r/h belt/pulley cover and discovered belt rub marks on the rear inside of the cover.   Removed l/h cover & belt from idler and ensured tensioner was free, lubed and had all of it's travel.   Then I realized that both the covers were the same.   Reinstalled r/h cover and noticed the forward edge of the belt was 3.25" from the front edge of the cover and the rear edge of the belt was about 1" away from the rear edge of the cover.  

 

Before tightening down the bolts, I rotate the cover [in the bolt slots] full counter-clockwise and gained about 1/2 - 3/4" more clearance from the rear edge of the belt.

 

If it were just me, I'd just pull the cover and run with it, but whenever my grandson hears me fire it up, he comes running to ride with me, so really need to keep it for safetys sake.

 

Was hoping you more experienced guys [gals?] could enlighten me as to was this the way WH did it or did a PO swap the proper r/h cover for a l/h one?

 

I'd attach pics, but it says their too big.

[Kelly 1,028]

Not sure on the covers, but how did you fit a 60" deck under a 312? I assume you have the little 6" front wheels, and how does the 12hp engine like running the monster deck??  

[Chat6155 3]

Yes, fronts are 15 x 6.00 x 6.   All attachment points were the same, even the PTO belt that came with the deck fit [mule is just about all the way out, but that's what adjustments are for].   Steering was a bit of a bear, only 'mod' I had to make was inflating the fronts from 15 to 30#.   Ms. Magnum isn't really a happy camper, but she troopers on.   Only asks that I engage the PTO s-l-o-w-l-y and once engaged, when I throttle her up, to be patient and wait a bit for her to dance at 3000 rpm.   After that, she just goes and goes.   I'm keeping a close eye on oil level and breather output.   But to be fair, no hills to speak of, just alot of area.

[cheesegrader 433]

Properly installed covers should be parallel to the spindle belt.  The back walls of the covers should be perpendicular to the frame of the tractor, level with each other.

It sounds like you have two left hand covers, with one pretending to be a right-hander.

[Shuboxlover 474]

I would LOVE to see pics of a 312 with the 60incher under it!!!!!!!!!!

[Chat6155 3]

Cheesegrader...thanks, that's what I thought.   If it still 'ticks along', may attempt to hunt the proper one down.   Are you still AF or retired now?

 

Shuboxlover...I've got pic's, but the site says they're too large to upload.   She has more wingspand then fuselage, but she does produce a wonderful cut and has cut at least 25% off my seat time.   Biggest problem is that she's now relegated to local area.   Mower deck is 65" wide and utility trailer is only 60" wide.

Edited August 27, 2013 by Chat6155

[cheesegrader 433]

Chat,

 

In the immortal words of Sgt. Hulka,

"I'm too old for this Sh*t"

[Shuboxlover 474]

How does that 312 steer with the 60"???  I had a 520-HC one time (the HC's don't have steering reduction) and the 60incher made a man of me even with the bigger steering wheel?

 

Just wondering

Edited August 28, 2013 by Shuboxlover

[Chat6155 3]

Shuboxlover...only 'mod' I had to make to the tractor: bring the fronts up from 15 to 30#.   Now steers the same as when it had the 37 and 42" decks.

[js5020 111]

Sure would be nice to have pics of this combo!

[312Hydro 473]

I want to see this too. I also bought mine in 1990. BTW

Edited August 29, 2013 by 312Hydro

[MalMac 1,328]

Wow a 312 with a 60" deck. I had one on a 520 and thought it was a bear. Did a great job of cutting but was still glad to get rid of it before it killed me or the tractor. More power to ya. Literally.

[Chat6155 3]

Didn't realize it was such a big deal.   Give me a chance to play with the camera and see if I can get the size down a bit.

[Chat6155 3]

Ok, as requested...

[js5020 111]

Thanks for the pics!

[C-160 Auto 10]

That's impressive.  I wouldn't have thought the Kohler 12 would spin it fast enough to cut. I'm sure it is getting a workout though!

[Hodge71 663]

Seeing this makes me nauseous....I really must have problems with the engine on my 18 auto because it definitely doesnt like turning my 60 inch deck...... If a 12 horsepower does it without any problems  my K-482 must be just about dead then..... 

Edited August 31, 2013 by hodge71

[js5020 111]

I was just looking yesterday at my 60" 3pth mower for the compact tractor,,, I dont think it would fit between the tires on the 16 Auto?

[Chat6155 3]

WH manual stated max governed speed of the M12 was recommended at 3400.   I tweaked it down to 3000 - 3100.   Not an engineer by a long shot, but figured if I only used about 90% of the power [more or less], the engine would last longer.   I've had zero issues out of the Kohler, but now, driving the deck, I'm keeping a very close eye on the oil level and the breather outlet in the air cleaner as this will probably show any early signs of distress.   And, if need be, if the governer was tweaked down, it can be tweaked back up, too.   But, as is, it really gives a nice cut.

 

Now, that being said, with the deck engaged, my forward motion does not rival Richard Petty coming out of turn 4 the last lap of Daytona, either.

[leeave96 487]

WH manual stated max governed speed of the M12 was recommended at 3400. I tweaked it down to 3000 - 3100. Not an engineer by a long shot, but figured if I only used about 90% of the power [more or less], the engine would last longer. I've had zero issues out of the Kohler, but now, driving the deck, I'm keeping a very close eye on the oil level and the breather outlet in the air cleaner as this will probably show any early signs of distress. And, if need be, if the governer was tweaked down, it can be tweaked back up, too. But, as is, it really gives a nice cut.

Now, that being said, with the deck engaged, my forward motion does not rival Richard Petty coming out of turn 4 the last lap of Daytona, either.

FWIW - if you look at the torque curves for these Kohler single cylinder engines, they are designed to run at 3600 RPM's and max torque is around 3200 RPM's - give or take. So when you wade into a tall spot of grass and the engine starts to come under load, the RPMs fall into the max torque range. Running the 60 inch deck, you might want to run the engine at max RPM's.

Nice set-up.

Good luck ,

Bill

[MalMac 1,328]

leeave96 is right. Run that Kohler at Max RPM 3600. That is what it was designed to run at. Anything under is just hurting the engine. Belts, tranny are all designed to run at that RPM.  With running that big deck it will task that motor to the max. I don't want to be a downer here but that tractor and motor was not meant to handle that deck. Just watch how much you work that motor. If it was anything different than that Kohler Mag on there it would have come to an untimely end.

[boovuc 1,090]

I still don't understand how that 60" deck is under that 312 without the tires hitting the deck itself on sharp turns but there it is! Now I wonder...........on 520's without the HD front rims and spindles and no gear-reduction steering, (an older one if any at all), could you swap out the spindles for the 6" tires and do the 60" deck? (And the bigger question is, how much is the turning radius and how hard is the steering)?

Also, on a tight turn, could that deck move forward enough due to the terrain and keeps the tires from straightening or prevent the tires from turning when needed due to a little forward movement of the deck?

[Chat6155 3]

Just an update for anyone interested...This weekend [Memorial Day] was the 5th time I've used the now labled 'Master Blaster'.   The cuts have been fantastic and the time cut noticable.   While WH never intended the 60"er to be installed on a 312, I've only come up with 3 issues so far...

 

Issue #1:   I'm using the belt that came with the mower deck [assuming it was from the original 520] and have had no issues with slippage, jumping or twisting at all.   However, if I do lift the deck, I learned to do it with the PTO disengaged.   The belt rides close enough to the front of the deck, just right of center, that the belt will 'polish' the edge [pic] if the deck is raised.   Of course, this causes no real harm to the deck, but probably doesn't do the belt any good in the process.

 

Issue #2:   [boovuc];   Tire clearance.   This is the big one.   First, since there is no fore/aft movement relative to each other, rear tire clearance is more than adequate [rears are 23"...pic].   Fronts are a different animal.   The 312's wheelbase measures out to about 45".   Front tires are labled as 15"ers, but tread is well worn down and with 27-30# of air, actually measure about 14" diam in the center.   While this is all well and good for straight ahead and moderate turns, if turned full lock in either direction, the outer edge will come into contact with the deck and lock up if on moderately wet grass [pic is of left front...naturally, right front contacts the same if steering is turned full lock right].   Laying on the garage floor and sticking my hand under the deck while looking at the scuff marks, I discovered that contact is actually made where the center and outboard blade tips are in the 'dead zone'.   If need be, I could have my welder-guy cut and re-weld a shallow V shaped relief on both sides of the deck to accomodate the tire edge and not interfere with the blades.

 

Issue #3:   [leeave96, MalMac & C160Auto];   The M12...In addition to keeping a closer than normal eye on the oil level and breather output, I'm going to increase the max governed speed to 3400 [as both Kohler and WH manuals].   With a 1 to approx 0.75 - 0.8 ration between the crank / PTO and the blade spindle, that should put the blade spindle about 2650 rpm, give or take.   I've read somewhere that mower blades are most efficient if the tip speed is just below the speed of sound, but have never been clear on how to actually calculate that.   If anyone out there has input on this, I'd be glad for the education.

[ericj 1,576]

when i got my first 60" deck i didn't have a 520 running so sh.t and giggles i put it under a 416-H that i have with 6" front tires. i thought the belts would squeal when i hit higher grass but have come to realize that it was the pto clutch squealen. i did have some issues withe tire rub but knew that it was only temporary so i didn't worry about it. i mowed a season or 2 with that set up

 

eric j     

[boovuc 1,090]

Thanks for the pics and update.

That does look impressive under the 312.