Trouble starting my Z425B

Last week I mowed my lawn. The Z425 ran fine. I put it away. I filled it with premium fuel and added Marvel Mystery oil to the fuel tank-2oz. like I normally do. I filled it above the fill line so I dont have to stop 3/4 way thru mowing my yard. I do this frequently except at the end of the season. When I put it to bed for the winter I run stabilizer, STP gas treatment, and MMO thru the gas/carb and run it till empty. Yesterday I went to start the machine, turned the key, it got power- the hrs showed on the meter, then turned the key and got a click. The battery was 3 yrs old. It showed 12.67amps but when a load was put on it, it dropped down to around 10 so I replaced the battery with a new one that puts out 350cca. I put in the new battery after making sure it was fully charged, turned the key, choke was on, and the motor was hard to start. I cranked it several times for 5 sec each then it finally started. It ran for about 10 sec., out came a lot of smoke and about 1/2 oz of fuel blew out from some where. I checked the oil, its full. I let it set for 5 min and restarted it. Same thing happened. The paper air filter is dirty so I am replacing it along with the top air filter, fuel filter and spark plugs-the plugs were dirty with carbon and fuel. I thought using the gas additives would help keep everything clean, am I wrong? Did I damage anything and could the new battery be producing to many cca that could damage my electrical system. Thanks for any help.

12.67 volts dropping to 10 volts....not amps..........your replacement battery is fine........was the smoke white or black, did it clear up right away or keep smoking the whole time it ran?

pile81 said:

12.67 volts dropping to 10 volts....not amps..........your replacement battery is fine........was the smoke white or black, did it clear up right away or keep smoking the whole time it ran?

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Hi, thx for the quick reply. The smoke was white. I only let it run for 3-4 sec while it was smoking then shut it off.

Well white smoke is oil and sometimes after these mowers sit for a while they will shoot a puff of white smoke from the exhaust, if it continues to smoke as you run it then there is a problem....start it and let it rin for a couple minutes and see whay it does.....

pile81 said:

Well white smoke is oil and sometimes after these mowers sit for a while they will shoot a puff of white smoke from the exhaust, if it continues to smoke as you run it then there is a problem....start it and let it rin for a couple minutes and see whay it does.....

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ok today I washed the pre filter and changed the air cleaner and put in new plugs. I started it and it blew a whitish blue smoke. I drove it about 100 yds to my building that has power so I can work on it. It smoked the whole way. It stopped running once. I let it cool then made it inside the building. I opened the oil drain plug and as the oil was draining I smelled gas. When I pulled the oil filter it had gas in it. So now what can I check or do. Thanks pile81 for your help.

So your havin a carburetor issue with the needle not seating, or thr fuel pump is bleeding fuel thru the pulse hose into the crank case.....

I have thte same problem with my z425 and after reading this post I do not see a solution. My z425 has only 24 hours on it and refuses to start when cold. Only a blast of starting fluid will do the trick. Today its refusing to start with starting fluid. I cant believe a mower of this calibre is having a such a cronic problem. What is the solution? Any chance this is a warranty fix?

Vet1776 said:

I have thte same problem with my z425 and after reading this post I do not see a solution. My z425 has only 24 hours on it and refuses to start when cold. Only a blast of starting fluid will do the trick. Today its refusing to start with starting fluid. I cant believe a mower of this calibre is having a such a cronic problem. What is the solution? Any chance this is a warranty fix?

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You mower will not start when it is cold using the choke?

Nwatson99 said:

You mower will not start when it is cold using the choke?

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No, it will not start with with the choke engaged. Again this mower jas only 24 hours on it. I have only run ethanol free gas, all fluid levels are perfect, oil is clean & clear. Last night I tried to get it going and ran down the battery. It sputtered for 15-20 seconds with the throttle in the cool down position. In the choked / start position it does nothing but crank. I took the air filter off and made sure it could breath, which made no difference. I gave a 2 second blast of starting fluid which also made no difference. It has a few fuses under the seat which are all fine. I am worried about dissassembling anything as it relates to a warranty, if there is any. The mower was bought new in late 2012 from Home Depot. How are they about stuff like this?