Mz 5225 Won't start after it has been running Fine???

[bertsmobile1]

The problem has not recurred for me since that one time. However, I have had something else(possibly related?)the last time I used it. Every time I would engage the blades the engine would stumble, there'd be a puff of fuel smoke, & a second or two clattering(pre-ignition). This went on until I partially finished mowing & parked it for lunch. Went out later & it would not start without full choke or keep running except with half choke.....Fuel smoke fogging out the exhaust.

All I could come up with for a solution is possibly a bad float or float valve, or the general effects of ethanol fuel. So, I ordered some carb parts & cleaned the carb. Got it back together today.

Now it is up & running, but it's still not right. Have to start it with choke & keep it running with half choke until the engine heats up. After that it runs about 95%, but still stumbles & clatters every time I engage the blades.

The only other thing I can think of is the little solenoid on the fuel bowl. This is the 1st one I've seen on a small engine. Does it work with the float to control flow?

Jeff

Start with the quick easy & common. work back to the exotic , rare, difficult & expensive.
Symptoms are consistant with leanness.
2 ways for lean burn, too much air or not enough fuel.


crank engine & check fuel flow to the carburettor from the pump
remove float bowl and clean it.
Check that the solenoid on the float bowl retracts fully when the ignition is turned on . on most they earth out through the case.
crank engine & check fuel flow from the float valve
remove main jet & clean it

 

[bertsmobile1]

I have the same problem with an RZ 5424 with a Kawa motor.

It began with after mowing for a while, I'd stop for a drink, come back starter won't spin. Leave it for a while and starts right up.

Checked all connections, fuse, tested battery was fine, couldn't find anything.

This happened maybe 4 times(different days), so it was pretty consistent.

Next time it happened, I was tired of waiting or towing it to the garage, so I grabbed jumper cables and connected it to my jeep and bam, started right up! Excited, I run down and got a battery, even splurged and bought one with an extra 150 CCA! Swapped it out, everything ran great, but only that evening.(yesterday)

Today, my son tries to cut the lawn, gets halfway done, stops, it won't restart. Ugh! Grab the jumper cables, hook them up, makes no difference. I then disconnect jumper cables from Jeep, and decide to by pass solenoid. Starter spins and engine starts right up!

So, I don't think it's safety switches like seats, blades, etc..

The only things that make sense is solenoid and wire harness. I read on a different site, about a different mower/mower, someone commented the valves might need adjustment because they could be open causing the compression to be too high, but I don't know what to make of that.

Any ideas what to do next? I think I'm going to order the solenoid. It's $15 on amazon and looks like a 5 min change. But this is really frustrating.

I the starter spins when you hotwire direct to the solenoid or starter then you have a safety switch problem.
Confirm this by running a jumper from the hot terminal on the solenoid to the trigger terminal ( small blade ).
If it fires right up with no problems then again you have a switch problem.
From here it is a methodical process of bypassing each & every switch, one at a time till you find the culprit.
Start with the ignition switch, runs a jumper from the S terminal directly to the trigge terminal on the solenoid ( small blade )
If it spins, then check .
As a rule the ignition, PTO & brake & gear box ( direction lever ) switches are the ones that prevent the starter turning.
The seat switch plus one or more of the above kills the spark.

 

[porkchop]

Well I finally found out why my mower won't start after it's been running fine. To recap my mower would not start after say cutting half the yard and then I would stop and get off the mower to get a drink. When I would come outside and try to restart it sometimes it would not turn over. Infact I didn't hear anything from the mowers engine at all. Tonight the same thing happened. I figured it had to be a switch or something like that. Well I kept fiddling with the knobs and trying to restart the mower. Wouldn't you know I noticed the I believe it's called a PTO switch (the blade engage switch) wiggled just a tiny tiny bit. However when it's wiggled to a certain side (I believe the right side) the mower cranks right up. However when it's to the left the mower won't turn over at all. Doesn't even make a sound. Now the switch only moves maybe two hairs to the left or right. Apparently that's enough. The one thing I don't know is if it's the wiring or the actual switch itself. I will check that out this weekend. Hope this helps. Wow a fix for something I have had problems with since 2015 looking at the date I started this thread. Take care all!

 

[Padroo]

Thanks for getting back and updating such an old thread. :thumbsup:

A test light is an easy and cheap way of testing for voltage or no voltage. Get the wiring diagram for your mower and follow the yellow brick road.:wink:

 

[bertsmobile1]

Well I finally found out why my mower won't start after it's been running fine. To recap my mower would not start after say cutting half the yard and then I would stop and get off the mower to get a drink. When I would come outside and try to restart it sometimes it would not turn over. Infact I didn't hear anything from the mowers engine at all. Tonight the same thing happened. I figured it had to be a switch or something like that. Well I kept fiddling with the knobs and trying to restart the mower. Wouldn't you know I noticed the I believe it's called a PTO switch (the blade engage switch) wiggled just a tiny tiny bit. However when it's wiggled to a certain side (I believe the right side) the mower cranks right up. However when it's to the left the mower won't turn over at all. Doesn't even make a sound. Now the switch only moves maybe two hairs to the left or right. Apparently that's enough. The one thing I don't know is if it's the wiring or the actual switch itself. I will check that out this weekend. Hope this helps. Wow a fix for something I have had problems with since 2015 looking at the date I started this thread. Take care all!

Sounds like a duff switch.
The cranking terminals are the ones closest to the knob.
All sorts of things can cause you grief with these switches.
The one that really stands out was a random failure which ended up being ants inside the switch.

 

[Tractor Man NC]

Hello everyone! I need some help. I have a strange situation for you. I go into my shed and turn on the mower to back it out and cut the grass. As always it starts cold just fine. However the other day I cut half the yard and stopped it in front of the front door. I went in to get a drink and my hat since the clouds were going away. So after about five minutes I went out and tried to start the MZ 5225 and nothing. No clicking noise I mean dead silence. my cousin came over with his multi-meter and checked the battery and it was fine. After getting it back in the shed ( with Help) I parked it for a day. Then having another day off two days later I went to cut the grass and it started fine cold as it did before. Started right up. I didn't dare stop in the middle of cutting the rest of the grass though. Has anyone had this problem before? IS there an overheating sensor on this machine that might be acting up? I find this very strange. Thanks for your time in advance!!!

One last thing. I found on another site where someone with the same mower was having the same problem. Someone told them the air filter is bad or needs cleaned. Today I went out and cleaned my filter and yes the pre filter was very dirty. I don't know if that is the cure though. I don't see how it could be.

I will add this, my 2014 MZ5424 w/a Kawasaki FR730, only started having this same issue after 3 yrs and 250 hrs. I first make the connection that it was oil related, but it has done it with a full fresh oil level, and fully cooled. One thing I have tested us disconnecting and reconnecting the voltage regulator connections; it seems to work most times, of course there is no scientific reason why. With the VR right on the motor, I wonder if excess heat on an aging component is the issue.

 

[bertsmobile1]

Did you check the oil level this time ?
There is a low oil option for that motor which prevents the engine cranking if the oil level is low
After running for a while enough oil can end up everywhere else but the sump so the low oil level cuts in .

 

[csmdew]

I have the same 5424S with 730 engine and several yrs ago it started to click sometimes before it would actually start. After maybe a few clicks to many clicks it would then start like starter not engaging fully. Then is would work perfectly for a few starts and after I ran some marine gas thru it it started better than ever until this month. Last week it clicked 200 plus times but never cranked. So I tried moving all the items with safety switches and still click, click, click even with me off the seat. So I figured that the seat switch was maybe the problem so I tried tracing the wire back and came to large harness. After just touching the harness every sound stopped and get nothing happening. Solenoid, starter and battery are good but nothing happens when I turn the key now. Any way to bypass seat switch to see if that is problem, thanks. Not very good with electrical and carbs but everything else I can handle and follow instruction well if illustrated since old retired disabled vet. Would really appreciate some help on this, thanks. Also sorry for piggy backing this thread but is similar problem.

 

[bertsmobile1]

Well you are piggy backing on a piggy back on a piggy back..
Bypassing the seat switch will strike a blow for freedom from the authoritian overlords.
It will re-elect president Trump and make the USA the true land of the free not to be dictated to by any one, but it will do diddley squat to get your mower running .
But if you really must just pull the wire off and if that makes no difference, jump the two terminals on the plug & turn the key again.

When you are ready for constructive help then start a new thread .
It is free and painless .
On most mowers the seat switch is not in the cranking circuit and unless yours is connected through the timer yours s the same otherwise techs have yo bypass the switch to service the mower.