Given that they are off the engine, why not soak them in a 50-50 mix of acetone & ATF. From what I've read, that is the best 'penetrating' oil type mix.
You can use a small pipe wrench or Vise-grip on the unthreaded area to clamp the stud. You actually can go onto some of the threaded area as some will never touch the head(or the bottom of the nut) without running into problems.
tom

 

Been soaking for days a solution of a couple of corrosion busters. The studs are simply rusted as are the nuts. I feel sure I will be able to take them apart but I really don't want to put rusty studs and nuts back in if I have new ones available.

I am debating changing the governor arm since it looks just fine. No damage or noticeable well. I will replace the plastic governor gear assembly, but can't see a reason to pull the metal lever which looks fine. Suggestions are welcome.

The arm looks pretty good (2nd photo). Below is the exploded view:

 

I would check with Granger, Lowes, Home Depot, and Ace Hardware for replacement studs. Ace locally has a very good selection of fasteners. Hmm, maybe the 'Fastenal' company has a local store, but I know nothing of them except they sponsor a NASCAR team.
Are the studs a press fit? If so, I'd consider threading the holes and finding screw-in studs. Particularly as I don't have a press. If not, why not jam a pair of nuts together, and use them to tighten the stud back into the head, and then use two wrenches to break the jammed nuts apart for removal?
Ace carries English and metric sizes, so you may have good luck. Lowes has less selection, and is a very close match to what Home Depot carries.
If you are down the road from repairclinic, why don't you try them for the studs?

 

Last first... Repairclinic.com does not stock the screw in studs (these are not press in) used on the Kawasaki FD620D. They were my first thought. My Lowes has nothing resembling a stud in their drawers of fasteners. Home Depot is the same way. I do have a ACE hardware with a large area of Hillman hardware which I went to last night thinking they were open until 9PM. Nope, they close at 8PM. I tried Lowes, Home Depot, Advanced Auto, and O'Reillys for threaded metric studs. None of the stores have anything resembling a stud. The nut is just corroded onto the stud so it acted like a bolt when I removed the nut.

I am betting on the local Ace hardware have threaded metric studs in stock. If not I can wait until next week where there are numerous Fastenal like companies where you can even buy left hand threaded nuts and bolts in Metric and English.

I will make a quick attempt to separate the rusted on nuts if the quick trip to the local Ace hardware results in nothing.

Bill

 

Nice work. Depressing the new springs is a bit harder than the older springs.

 

Thanks, Yes, you got that correct.

The teardown was started just to replace the plastic geared camshaft which is likely to fail between 700 and 1000 hours. Mine has 760. So, as long as I opened up the engine I decided to lap the valves, put in new springs, tappets, pushrods and water pump. New hoses (water and fuel) will be installed as well.

I also have the snowblower attachment that really works well. It came with Cab enclosure which died a slow death from simple metal fatique from all the vibration. Mig welding the cracks was tried but eventually is darn near fell apart from all the sheet metal fractures. That said, the mower and blower set me back $9500 back in 1996.

This mower, if replaced would set me back $7 (used) to $10K (new). So, the mower is getting the engine fixed up. I have also bought a new radiator ($500 list but $175 off Craigslist) since the original had bent fins and 50% blockage with cottonwoods. Messicks had new old stock radiators for $270. It did run warm on hot summer days. Cleaning the radiator by picking out the cottonwood blockage and straightening the fins was done, but a new radiator was the right way to go. The powerplant should be OK. I had to pull the PTO so new belts will go in ($45). The mower deck tires were replaced with new foam filled tires but require some fabrication to fix extensive wear on the forks where the new, correct size tires rub the mower deck. In the rear I had already added a new, solid rubber rear tire but that tears out the bearing in two seasons so I found a New Old Stock dual tail wheel with air filled tires for $215 from Messicks. Again, this is NOS stock I bought for less that half price. When finished with maintenance I will have put in about $1000-$1200 in this old school ZTR which cost me $8500 in 1996. If done at a mower shop this would cost in the neighborhood of $3K if I only used by talent at writing checks or signing a credit card payment.

Who knows, I might even put a coat of paint on the mower deck and wheel wells on the colored sections of the mower .

As a side note, there were many complete motors being dumped on the market for $800 a few years ago. Now, a new motor is nearly $3K. I am suffering the "wish I had bought one" syndrome. Although, I bet the NOS engines came with plastic cam gear.

Bill