Simplicity 5216H problems

[SamPeterson 0]

I inherited an Allis 616H(Simplicity 5216H), which has two problems: The first is that the motor is not running very well. The idle is rough and there is some surging. When I take off the air filter, I can see the butterfly choke thingee automatically moving as the surges occur. At full throttle I can mow but the motor will stall out after 30 minutes or so depending on how hot it is outside. The mower has been dealer serviced most of its life but no one knows exactly what has been done to it and I think that the engine hasn't been touched much. I don't know what to do and maybe someone can help me. The hydro unit has suddenly started making noise, but still works fine. It has fluid and the shaft doesn't wobble. Can these be rebuilt? I have found what is probably a 5212.5H with a good hydro unit, but the mower has square headlights, where mine has round. How would I find out if the parts are compatible? Thanks!

[goatfarmer 817]

Could be a number of things with the running, from needing a carb rebuild, or maybe loose bolts holding the carb, to the manifold, to bad gas, plugged filter, etc. Is the fluid level OK in the trans?

[SamPeterson 0]

I think I will try to find someone who knows what they are doing. There is a Simplicity dealer down the road that I will call. The Hydro was low enough on fluid that the screen was visible and so I put some JD hydro fluid in it which still didn't help. The 5212.5H is $125 and I am probably going to buy it, especially if the hydro unit part number is the same as mine. I am going to look at the manuals on the Simplicity site to see if they are the same. Thanks!

[UCD 14]

There are some very Knowlegeable Dealers as well as some people on here that know more than most dealers.

[SamPeterson 0]

When it comes to diagnosing problems, how would I go about doing it? I am pretty handy mechanically, but have never been shown how to approach motor problems. How would a person do this?

[JohnMBerst 36]

Easy start is run a bit of Sea Foam through the carb, and hope it cleans it out. LOTS of smoke, but worked on my 16 hp twin. Clean the linkage well, blow off, and make sure the breather tube in air cleaner is working. (not full of sh..) My coil would quit after it got hot, so perhaps might look under the top housing making sure the fins are clean / clear for air to move down and out. OK my .02.