Toro 44" Z-Master engine re-gasket

Ok, so not really a build or anything spectacular but it is my first project since my accident and HAS to be done as A) this thing is hemorrhaging oil and B) summer is a coming and the lawn will NOT wait.

The mower in question. A 2000 Toro Z-Master w/44" deck and just over 300 hours. It has an air cooled Kawasaki 17hp v-twin (FH500V) engine. Not used commercially, just by me on my property. Overkill, yes but was it an awesome buy? Yes. I got is used with just over 60 hours on it for less than half of a new one AND the guy threw in the 8x10 lawn trailer for FREE! So far this thing has only gone through one set of belts, 2 starter solenoids and 2 batteries but she does love eating through blades in the FL sand. I usually put on a fresh set of mulching blades every year.

Near the end of last season I started noticing oil on the deck under the oil filter. It was really hard to tell where it was coming from but definitely somewhere higher up on the engine behind some shrouds. The breather cover on these is notorious for leaking and there is a retrofit cover to fix a weak cover issue. So lets look there first.

With the fan cover off it was easy to see the leak was on the right side of the motor due to the dirt build up.

Clean side:

Dirty side:

Still hard to tell where the leak is so off comes the carb, intake,, fan, & flywheel.

Well, breather cover looks ok and most of the dirt up here seems mostly dry.

Lets get the lower shroud off and look lower. Hmmm, pretty wet down here.

Hard to get a good shot but determined that the leak was coming from the crankcase cover. Damn, guess the motor has to come out. Gotta remove a bunch of stuff first. Rear guard has to come off to take the exhaust off.

Starting to get a pile of stuff. Zip locked all the bolts as it was going to be an issue.

Next comes the PTO clutch and belts. Filthy, and the underside of the mower is gross.

4 bolts and the motor is out!

Deck is going to need some cleaning.

Lets clean this baby's bottom.

Next, clean the engine and start disassembling and prepping for new gaskets and seals.

No pictures tonight.

Motor is back together and the last thing was to adjust the valves before putting it back in the chassis. Cylinder #1 went great. Valves right on the edge of tolerance so I tightened them up a tad. After taking the valve cover off Cylinder #2 the intake valve rocker fell off the pushrod with minimal touching. Uh oh.

Adjusted the valve tolerance and it just didn't seem right. Turned the motor over by hand and the intake valve isn't actuating properly. Pulled the #2 head and when the pushrods came out the intake one is bent. Also the valve has a lot of carbon buildup and the stem needs some wire wheel attention to get it to actuate smoothly.

Looks like I'm lapping some valves this weekend!

Did the pushrod get bent by the valve contacting the piston? Pictures of carnage tomorrow?

Cool thread! Good work!

In reply to Doc Brown:

No carnage. Valves have no damage just a lot of carbon buildup on backside of valve. Stems are straight and just need a little cleanup and should be fine. I'll try and post pictures tomorrow.

The service time for checking the valves/seats is 300 hours and I'm just over that. My guess is that the valve started sticking and the pushrods bent over time.

The engine had been intermittent on power and seemed to be dropping a cylinder on and off. I was hoping it was an electrical issue with the amount of funk on the igniter but 'twas not to be. A new pushrod is under $3 online and I hope I can find one local for slightly more. The hardest thing to find may be a small valve lapping tool. Local online sources don't seem to show any in stock.

Small valve lapping tool.....I got mine at OReilly Auto Parts. It's quite small as I use it for lapping Honda 70cc motorcycle engine valves. It cost just a few bucks.

In reply to Cousin_Eddie:

Thanks. I had checked them online and they didn't show any stock but I stopped by the one on my way to work and they had one on the shelf. A double pack of light/heavy lapping compound and I was on my way. Got to work and called the closest mower repair shop and they had 1 pushrod on their shelf! Score. This thing may be back together tonight!