Small engine question

My Toro Zmaster has a 19hp Kawasaki engine. It is about 6 years old now. At the end of last year, and upon startup this year, it is cycling up and down at idle and low rpms. It runs fine and does not smoke. Mower has about 260 hours. Just changed the oil and topped the hydro fyi. Any thoughts?

 

Do you mean the rpms fluctuate up and down. If so the carb needs cleaned or adjusted.

 

There is some sort of mechanism on these engines, same on my power washer, that will throttle the engine on its' own. It appears that is working overtime. I am guessing its' function is to avoid stalls.

 

Most likely some crud in one of the carb jets causing this as rookie suggested. I can probably get you the manual for it with model and serial numbers on the mower itself, not the engine numbers.

 

I tried a little brake cleaner as the engine was running. No change. Didn't overdo it though. I will get some carb cleaner today and give it a go.

 

This may help with taking it apart and cleaning it out. 20 HP but it should be a similar carb.

 

Your air filter isn't clogged is it?

 

No clog there. Cleaned that out and ran it with the filter off while spraying cleaner into the carb. I think the carb is buggered up, like the previous posters believe. I have never winterized the machine and it is out of commission for 5 months usually.

 

I'd add some Seafoam to the gas and use it like normal if possible. Since regularly using that method on all my external equipment gas, I haven't dissected a carb yet. Could be luck, dunno.

 

I have one of those. Its the Z449. 19hp Kaw with 48" turboforce deck. I bought it used in 2007 with 32 hours on it. about 230 hrs now. Its been dead reliable, got a 2"x5' stick up on the deck once emb: don't ask) which knocked the belt off and it got chewed up badly by a pulley. Other than that, just maintenance. I mow 5-6 rough/hilly/rocky acres with it.

 

I ate up a belt in similar fashion. Cost me over a hundred bucks for the new one! I had something odd and unexpected happen to mine. Last year I noticed a hydraulic leak around the left side drive wheel. I put a floor jack under the rear and started to lift the mower. As it raised, the rear tires started to cant under the mower. Knowing this is not a suspension system, I was quite curious as to how this was happening. Turns out the 4 bolts that hold the wheel/drive assembly to the frame were very loose, one even gone. Both sides were loose. Not sure how that happens, but I was unimpressed. Beyond that I love the machine. Dropped my mowing time by 60% and improved the finished product while doing it.

 

Looked at the Seafoam today. Opted to try the cleaner first. I just don't see using Seafoam all that often and it is not cheap. If the Seafoam acted as an Ethynol treatment, I would have bought it and used it in the saw mix. I will try adding some to the fuel tank. Thanks boss!

 

Sounds like ethanol attack- Get the Sea Foam and run it. It will take several tanks of mix to cure the ethanol attack. Dang stuff wasn't worth squat in the 30's ain't any better now. When it sits it absorbs moisture even when ya run the system dry. cruds up the various passages and jets in the carb, attacks the fuel lines ( newer fuel lines are a lot better, just takes longer for the effects to manifest themselves) Ever wonder why most of the tanks are a type of plastic now? ( besides being cheaper to make)

 

def the carb. our fuel today sucks with it's 10% methanol. it gums these things up real good. I put stabil in everything nowadays even if im not storing it for a long time to eat some of that out. (neighbor gave me that hint a while back and it's seemed to be better for my mower/etc)

 

I put Stabil in every drop of gas that goes in my small engines, no matter how long it's going to sit in the can/tank. I've been doing that for 9 years now (since I became a homeowner) and I've had zero carb related problems. That's one ZTR, one garden tractor, one push mower, one tiller, one power washer, one blower, one chipper, one snowblower, two weed wackers, and a generator. Hate to admit it, but I usually don't even drain the gas in the winter.

 

More than likely, water in the float bowl. just take it off & clean it out, put it back on & it should run fine. just a side effect of todays gasoline!

 

Sea foamed my Tractor yesterday, poured some in the carb while it was running and smoked up the neighbourhood, then put some in the gas tank, good stuff.
My Honda pressure washer it was doing the same thing as your mower, myway it straightened up a little bit after old gas was dumped, fresh gas was put in, but its still not right haven't fixed it yet, I will, I don't use it a lot

 

Just a little tip. Adding fresh gas to a tank of old ethanol that is tainted wont fix it. all the ethanol needs to be dumped out and the floatbowl removed and cleaned out to fix the problem.