Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I purchased a brand new Ariens Platinum deluxe 24" snowblower in October of 2009.  I paid $2000 Canadian with tax.  A few weeks ago, I used the machine for the first time to clear about 5 cm of snow.  Unit started up well and removed the snow.  Then, when I went to shut down the unit, it backfired and two flames/sparks came out of the exhuast.  I went to start the machine up again and it wouldn't start even though it had been running for 20 minutes.  So, I opened up the choke, primed the unit and it started.  Upon shutting down, the backfiring happened again and again it wouldn't start.  So, I contacted Ariens.  There response was:
1. Put the throttle down to half, let it idle for about 30 seconds and then shut it down.
I did that and still the backfiring happened.  So back I go to contact Ariens.  They tell me to take it back to the dealer.  I did and they:
1. changed the camshaft
2. started 4 other Ariens machines and they all did the same thing.
3. Contacted Briggs who told them the backfiring is caused by the engine running lean so that they could make it through emission restrictions.  They also told the dealer to tell me not to worry about it.

At this stage, I'm frustrated.  I find it unacceptable to pay $2000 for a machine and have it backfire right from the get go.   Interestingly enough, the dealer had a single stage toro 421 and a powerlite.  Both units come with the 4 stroke Chinese made engine from Loncin.  He started those up and neither one of them backfired.  

I don't understand how Briggs can let this go.

Now, I don't know whether to:
1. Just keep the unit.
2. Push Ariens to do something about the unit.  Ariens uses the snow series Briggs.  I wonder if the Snow Max series does the same thing.
3. Push Ariens to give me my money back.

Any idea/feedback?

borat wrote:
What happens on these extra lean running engines is that the muffler gets very hot as a result of the lean burn condition of the engine.  If you turn off the engine at full throttle when the engine is hot all that is happening is that the spark is killed to the spark plug but fuel is still being dumped into the engine because the throttle is wide open.  The unburnt full is then pumped out of the cylinder into the burning hot muffler.  When enough air is mixed with the unburnt fuel BOOM.  This will not harm the engine in any way but running that lean might.  If you have a throttle idle the engine down slowly and let it sit for a minute or two at idle for the muffler to cool down some before turning it off.

Carl

carlb wrote:

Great insite !!!!!

Like the other said, the lean carb jetting, and it could be the ignition timing setting. Your dealer is never going to help you because the factory will void the warranty if the dealer changes what needs changing (carb tuning and maybe the timing) pus the legal issues.

The muffler could also have a catalytic converter inside- take off the muffler and look for a honeycomb plate or chamber inside. You can decide haw to handle that.

I stopped buying the newer OPE and only buy and fix older units. EPA is sheeiit.

I hear your concern.  Something someone did and mentioned the process on another forum for a clone engine was open up the jets.  He said that he couldn't get any other size jets for his engine so he took them out and used dental floss and some mild abrasive to open them up a little.  Said it got rid of all his surging and other issues relating to the engine.

Obviously I don't recommend this if you have a warranty but if it's out of warranty, it's sure worth looking into whether you can change out the jets or not, or be able to modify them a little.

     There's no backfiring B&S OHV here at the moment to try the following on but it might work. 

     Get the machine to it's lowest idle then punch the primer to choke it off.  That might work.  It depends on what exactly is causing the backfiring. 

     The new B&S OHV designs backfire and the older properly running L head Tecumsehs never did.  The older usual reasons for backfiring don't seem to apply.  Your dealer suspected a very likely valve issue so replaced the crank.  Nothing changed.  Good running to spec B&S designs just backfire. 

     One possibility for the backfiring might be the design of the idle circuit and high speed for better compliance with the EPA.  The backfiring happens when the rpm is low and engine shut off i.e. coil grounded. 

    The engine is still spinning and the venturi speed slowed way down.   The carb then would be transitioning from high speed to the idle circuit or just on the idle circuit.  The new design may be dribbling the last gas from the high speed or pulling from the low which is just starting again to get enough gas to the head for a backfire with the spark grounded.  It's just the right amount of air, at the right flow and gas get to the head to fire.   Modifying that may make a change. 

    The air flow can be changed by putting on full choke.   That will also richen the mix.  The amount of gas can also be further changed by a few stiff pumps on the primer for a flooding condition.   A lot of gas will go to the head, less air and what gets there will be less atomized than usual.  The flooding might just work and quickly dry in the head and not interfere with a quick restart.   

i have a 2012 Ariens deluxe 30 with the 342CC engine.  Mine will backfire every single time i idle down from full open to idle.  Even trying to slowly return the throttle would almost alwasy result in a backfire.  I called my dealer and they call Ariens, they said they know of the problem and the ignition coil needs to be changed.

I have a 16hp briggs on an lawn tractor and to help stop this type of problem they installed a solenoid where the bowl nut normally goes and a plunger plugs the jet as soon as the ignition is turned off to stop any additional fuel from entering the engine.  Personally I find it to be a pain in the ass.

Carl

carlb wrote:

Lots of new engines have those fuel shutoff solenoids now. Yet another thing that has to be tested whenever you have a problem.

#$&$^&$% you, EPA.

This isn't even a new engine.  Its a 1992 briggs and stratton i/c gold made in the USA before they epa really had much to do with these small engines.  I am in the process of rebuilding this engine because the rings finally wore out after 20 years of very very hard use.  The rest of the engine inside looks like new  the bore looked great but a little glazed,  honed the cylinder put a new ring set on and new gaskets and it should be good to go.  I will be removing the solenoid and just put a regular bowl nut in its place because when i pulled the terminal off the bottom of the solenoid the tang on the solenoid broke off and I have bowl nuts laying around and the solenoid is around 40 dollars and not worth replacing.  I always throttle my OPE down before turning it off and don't expect to have a problem.  If it pops out of the exhaust when i shut it off i really don't care the muffler is pointing out of the front of the tractor anyway.

I had a Toro lawn tractor with a B&S engine and it does the same thing, always backfire during shut down.  The effect can be lessened by throttling down before shutting off, but it does so still.  Very annoying.

My other Toro push mower has a B&S side valve engine.  It rarely backfires.  However, it is difficult to restart once the engine is hot.

Both engines have been reliable so far, not knocking on B&S engines, but they are annoying engines that leaves me not too fond of them.  Seems like B&S just thinks they're good enough to leave them alone and not take care of these things.