[mtn man]

Hello everyone --
I've been a lurker here for many months, but never registered because I had nothing to contribute. I still have nothing useful to contribute, but I need some info, and I know you are the people to go to.

I have a 1991 Rally lawn tractor, made by AYP. It has a 38 inch mowing deck and a 12 HP B&S I/C engine. I bought it used last year, and it appeared to be in good running condition. Until now, it has run flawlessly. I have several questions:

-- After changing the oil this afternoon, it began sputtering, as if it was running out of gas (which it wasn't). I found I could remedy this temporarily by pushing the throttle lever from wide-open to the choke position, just for a moment. After doing that, the engine would run fine for 3 or 4 minutes, then would begin to sputter, until I again engaged the choke for a moment. That cycle repeated until I was finished. There's no way an oil change could have caused this, but it never did it before. Any ideas on what might cause this?

-- The last several times I cut the grass I noticed an odd rumbling sound coming from the mowing deck. I should have checked it out immediately, but foolishly waited until today (while I was also changing the oil). I was suprrised to find both blades loose, and one of the mandrels cracked. I'm reasonably competent with a wrench, but I'm definitely not anything even resembling a mechanic. I also have no experience working on a lawn tractor, so the mowing deck is entirely new to me. Is a mandrel replacement something I can do myself, or should I take it to a shop?

-- Related to my question above, I have no owner's or repair manual for this tractor. What do people think about "generic" repair manuals, such as this one, currently listed on e-Bay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=36343&item=4315311645&rd=1

In case that link doesn't work, it's eBay item # 4315311645. From the description, this manual sounds pretty good, except that AYP isn't among the list of manufacturers this manual claims to cover. Would a manual like this one be of any use to me at all?

Sorry to introduce myself with such a long post. I figured this would be the best place to go for answers to these questions.

 

[Ernie]

Welcome mtn man. I am sorry to here of the problem w/ your mower. I do not own a lt and can only help w/ what you have told us the problem of keeping your briggs runnuing... Does it have a fuel filter? Just a thought. have you cleaned out the fuel tank? These are the easy ones to get at,,, It sounds as if you are having a fuel delivery problem and the easiestthings to look for I have mentioned.. If these are not the problem, the next step is into the carb it self, possibly dirt at the needle valve or a sticking float., all of whichcould cause the problems you have cited... As a last resort if you can pull the flywheel and check the key way to make sure that it isn'twacked at all because timing is most important to these engines..... Now a s far as thecracked mandrel replacement I am going to defer to the other owners with in this forum to assist you....


Again welcome to Tractor forum.com

 

[aegt5000]

mtm man…

Welcome to the forum.
I agree with Ernieg, sounds like you have a fuel delivery problem,
or picked up some bad gas. Did you refuel the tractor when you
changed the oil ?
I would try the following :
Change the fuel filter. The tractor probably has an in-line gas filter.
If you bring it to your local “Lawn Mower Repair Shop” they should
easily be able to match it up with a replacement.
As you disconnect the fuel line from the old filter, put about 1 inch of
gas from the fuel line into a small clear glass. Set the glass down for a
couple of minutes and then take a look at it. If there was water in the
gas, it will be beaded up, laying on the bottom of the glass. If the gas
has junk in it, it will also settle on the bottom of the glass.
If you don’t see any indication of water or junk at the bottom of the
glass, the gas in the tank is probably OK. If not, dump the tank and
your gas can and replace the gas when you change the filter.
Post the engine Mod and Spec #’s, Brings has manuals on line and we
can probably link you to a free copy of the engine’s manual.

Changing the mandrel should be pretty straight forward, if you are
reasonably handy with tools. The real problem will be making sure
you get the correct mandrel. You will need to find out who sells parts
for these tractors. I’m sure someone else will post some help with how
to get a replacement mandrel.

 

[waynl]

Hi mtn man. Nice to have you aboard!

You say your engine problem started after changing the oil? If it ran fine right before the oil change but lousy immediately after the change, please double-check the oil level to make sure it is not overfull. Too much oil in the crankcase can cause problems similar to what you are describing.

As far as the mandrel...changing one is usually easy. Sometimes the hardest part is remembering how the belt was routed. But you need a replacement part and finding one for your brand may not be so easy. First off, try a local mower shop (or maybe a friend who knows sommebody in one) to see if they can help you. Try some internet searches to see if an outfit sells the parts in question. BTW, the mandrel is more often referred to as a spindle so use both terms in a search. And maybe somebody else here on the forum knows of source for such parts.

Hope some of this helps.

waynl

 

[Chipmaker]

Personally I would save my money for a real manual on the tractor. Generic manuals are just that......nothing specific, just a glossing over of proceedures, which may or may not get the job done........

I also think your problem lies in either too much oil was added during the change or fuel delivery. A filter change is cheap and quick, and I would also remove the bowl on th carb and check for water or junk in the carberator bowl.........

Spindles (mandrels) usually are not hard to replace. Is it the housing of the spindle thats cracked? I would not think the spindle itself is cracked. Often times housings are available and you can utilize your old parts to rebuild (bearings, spindle etc) Draw a diagram of how your deck belt is routed over and around the various puilleys and how any tensioning devices are attached, and remove the blade and mount bolts and pulley from the spindle and have at it. Basic hand tools are usually all thats needed. There are lots of places online that have after market parts for all kinds of machines.

 

[mtn man]

Thanks for your guidance and suggestions everyone. I'll definitely check for crud in the gas and change the filter, but since it was a direct "before-and-after" problem, it sounds like I may have overfilled the oil. I don't have the engine spec. number handy (it's pouring right now and I don't want to run out to the shed), but you folks will probably know this right off: when I check the oil level, is the dipstick supposed to be screwed down all the way, or is it supposed to just rest on the tip of its tube? (That gets to the problem of not having a manual.....) Since I wasn't sure, I thought it was best to err on the side of overfilling. I laid the dipstick loosely on the top of the tube, which means there's at least a half-inch more oil than would be the case if the stick were screwed down all the way.

In terms of parts availability, I assumed that since AYP also makes Craftsman tractors, I would be able to get replacement parts at Sears. I figured the only difference between my Rally and a Craftsman was that AYP just put some different trim on, shaped the hood a bit different, and painted it a different color. Gues I'll have to check to see if Sears parts will work. If not, there are many outlets on the net.

Anyway, thanks for your help. Chip, no, I'm not sure if the spindle itself is cracked, or if it's just the housing. I guess I'll drop the deck, pull out my wrenches, and see how much trouble I can cause!

 

[Chipmaker]

I would not hold my breath on AYP and Crapsman parts being swapable. Crapsman dances totheir own tune and has lots of items made to their spec just so they can acquire a lifetime customer to buy their parts.

I can't speak for all engines, but every engine I have or worked on that has a screw in type dipstick or even the older half turn types all had their oil level checked with the bottom of the cap resting on top of the dipsticks tube.

Its possible the filter gave up the ghost when you changed the oil. Just think of how many foks you have probably heard of driving in a car for a oil change and having to replace the ignition module just to get it to start after they were finished and other such oddities as that. I did an oil change on my old pickup one time and it cost me a fuel pump, and it ran great right up until I changed the oil, and thats when it died......but usually on a small motor as you have there just is not all that much that can just up and die.

I diod a quick look on th web and there are lots of aftermarket spindles and housing assemblies out there. I did not know your exact model of machine and am not all that familiar (not any actually) but tons of aftermarket parts for a lot of machines are out there. Let us know how it turns out and what the problem was on the sputtering as well as the spindle assembly. Changing the spindle assembly is really a pretty easy task in most cases, so don't be afraid to tackle it.

 

[memmurphy]

Here's a link that might be of some help.

AYP Parts

They show some pictures of spindle assys. Maybe you'll be lucky and one will look like what you have. I have not delt with this company. So shop at your own risk. You might be able to find a owners manual on Brigg's webpage using the number stamped on the engine cover. See link below.

Briggs & Stratton

Good Luck.

Mark

 

[mtn man]

Thanks again to everyone for your very helpful posts. I replaced the gas filter, drained crud the tank (there was very little), and drained out some oil. The engine runs perfectly once again. Now I just have to find the time to replace the spindle. Between several meetings I have to attend during evenings this week and a mandatory visit to the in-laws this weekend, it may be a while before I get to that job. I'll let you know how it goes -- or perhaps more likely -- I may post another request for help if I get stuck. Thank you all for taking the time to assist me. This is truly a great forum.

 

[memmurphy]

Glad to hear you got the engine problem solved mtn man. Don't be a stranger, and welcome to the forum. :friends:

Mark