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If it don't crank, that is a battery/ starter issue; not at all related to the backfire, running issue. It should crank over regardless of fuel/ sparkplug,
Don't buy a fuel pump rebuild kit yet.. is yours EFI electronic Fuel injection? Do you hear the fuel pump engage when you turn on key?
 

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I changed spark plug, still backfire every 20 seconds, the engine is starving for fuel. I will try check filter inside the tank, and if not solved then take to dealer for repairs. Maybe fuel pump is clogged or not working properly.
 

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So you think it's starving for fuel but yet it's backfiring, interesting theory!!! Simplist test would be to chk for spark!!!
 

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A backfire is normally associated with excess gas passing thru then exploding from exhaust heat.

Lean fuel normally is associated with a power loss upon thromping on the throttle, it might putt putt but not have enough spritz of fuel / air mixture to burn efficiency.

We must not lose sight of being the 570 is EFI, the importance “air” mixture plays in burning gas.

For instance. If your injector spritzes fuel, but air, which is needed for combustion is not sufficient, you don’t get enough explosion to expel all your gas. The gas passes thru unspent where it explodes outside your cycle/piston cylinder but past the valve port.

Therefore if I’m thinking this thru properly, I might look @ the air mass flow sensor ? So, a diagnostic test is in order, and might now show up on idle or a bike that is not warmed up thoroughly.

So I’d run her hard enough to where she’s popping, shut her down and quickly plug the diagnostic hook up to her and Rev up to obtain a pop or two.


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A backfire is normally associated with excess gas passing thru then exploding from exhaust heat.

Lean fuel normally is associated with a power loss upon thromping on the throttle, it might putt putt but not have enough spritz of fuel / air mixture to burn efficiency.

We must not lose sight of being the 570 is EFI, the importance “air” mixture plays in burning gas.

For instance. If your injector spritzes fuel, but air, which is needed for combustion is not sufficient, you don’t get enough explosion to expel all your gas. The gas passes thru unspent where it explodes outside your cycle/piston cylinder but past the valve port.

Therefore if I’m thinking this thru properly, I might look @ the air mass flow sensor ? So, a diagnostic test is in order, and might now show up on idle or a bike that is not warmed up thoroughly.

So I’d run her hard enough to where she’s popping, shut her down and quickly plug the diagnostic hook up to her and Rev up to obtain a pop or two.


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Thanks for the great info, suggestion! I have removed all gasoline and will add new fuel today, I will remove the new sparkplug and visual check for spark quality. Is it for sure that starving for fuel can not cause backfire? It can only be excess fuel, + air mix / poor spark ignition that can cause backfire? In summary- my fuel pump can be rueled out of equation?
 

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If you have spark then you chk pump pressure.
 

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Thanks for the great info, suggestion! I have removed all gasoline and will add new fuel today, I will remove the new sparkplug and visual check for spark quality. Is it for sure that starving for fuel can not cause backfire? It can only be excess fuel, + air mix / poor spark ignition that can cause backfire? In summary- my fuel pump can be rueled out of equation?
Anything is possible. I’m trying to just break it down.

Back firing can be timing etc. but even with timing, you are getting un exploded gas exploding elsewhere.

Fuel pump ? Well your air flow mass sensor and injectors quite possibly can be mixing properly but your fuel pump would more than likely be having to pump more gas than is needed. More often then not, when a pump goes bad, it pumps weaker flow of gas. You can I do believe measure your gas pressure coming out from your pump. As long as it stays steady, pump should be ok.

With excess gas exploding, I’m looking for why gas is escaping thru valve ports un exploded. Unexploded gas mean bad combustion meaning not optimal air/gas mixture, piston timing.

So my point was not that I have the answer but where I would begin to explore location of issues.


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If you have spark then you chk pump pressure.
I dont have a gauge to test fuel pump pressure! I removed fuel pump assembly today, siphon all fuel, and then vacuum tank clean, high pressure the fuel filter. Added 1 gallon of fuel, + injection cleaner. Replaced the new S. plug with another new one. Sadly.. no change in performance. Maybe a timing issue as the backfire is every few seconds... non-stop. I will take to dealer tomorrow for diagnosis. I have it already stripped down.
136235
 

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A backfire is normally associated with excess gas passing thru then exploding from exhaust heat.

Lean fuel normally is associated with a power loss upon thromping on the throttle, it might putt putt but not have enough spritz of fuel / air mixture to burn efficiency.

We must not lose sight of being the 570 is EFI, the importance “air” mixture plays in burning gas.

For instance. If your injector spritzes fuel, but air, which is needed for combustion is not sufficient, you don’t get enough explosion to expel all your gas. The gas passes thru unspent where it explodes outside your cycle/piston cylinder but past the valve port.

Therefore if I’m thinking this thru properly, I might look @ the air mass flow sensor ? So, a diagnostic test is in order, and might now show up on idle or a bike that is not warmed up thoroughly.

So I’d run her hard enough to where she’s popping, shut her down and quickly plug the diagnostic hook up to her and Rev up to obtain a pop or two.


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Thansks! Yes I will take to dealer tomorrow $$ 😪 I suspect your are correct! I expect it is timing or one if the sensors related to air flow sensors. It backfires when cold and when hot also, and it seems to get hot quicker than usual.. maybe? The speed is 20mph. Max full throttle in H. And low.. now power no speed.. lots of 💥 💥 💥💥💥 💥 every few seconds.
 

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have 570 Polaris 2014 . Is backfiring and popping and misfireing. I put on a new spark plug and new coil and I checked the fuel pump Reading 52+Psi nothing wrong with my fuel u pump .and new Air filter and new strainer on the bottom of the fuel pump too . And Stalling and backing 1250 1200...
 

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have 570 Polaris 2014 . Is backfiring and popping and misfireing. I put on a new spark plug and new coil and I checked the fuel pump Reading 52+Psi nothing wrong with my fuel u pump .and new Air filter and new strainer on the bottom of the fuel pump too . And Stalling and backing 1250 1200... everyone have the same problem
 
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