My rmz 450 2010 model starts then stops after running for 6 seconds. Its not the fuel or the spark plug what could the problem be.

check fuel pump pressure unit maye its relase after the 7 seconds

suspect that the diaphragm is going hard and is not sucking the fuel up from the tank properly
rekit the carby

no engine size stated, (so i toss coin, 4.0L) 5miilion strong.
the 1988 is the gawd awful French RENIX fuel injection.
i owned 2 of these pigs. (sure it runs) but sux.
why?, no CEL lamps , no flash codes, no OBD1 , no OBD ! anything.
only the very old and rare factory and dealer tools can scan this pig.
lets do this better?
in vivid details.
NO start 101: (order matters too)

1. compression at spec, on all 6 cylinders? (old engines do die)
2. spark at all 6 spark plugs good,? not just 1.
3. car is tuned up. spark plugs.cap rotor, wires, and filters?
4. the ign timing light on #1 wire, shows spark landing near TDC 0 degrees or under hood stated spec. (open hood look up )
5. i now check for flooding, is it? spark tips , TALK to me.?
6. yes, then check fuel pressure. next.
7. no, then are they dry, you said wet. ('gets fuel means what"?)
8. if flooding, i unplug the fuel pump relay and start car with test fuel if it runs for 3 seconds and stops, that is a PASS condition so but if not 1, to 7 above was skipped. lets say its flooding
9. if flooding did you try cranking per opr guide wide open throttle? this CUTS all fuel and clears all flooding on all gas engines. and for sure all EFI. gas engines.
10. my guess is its running now. right? if here?
11. if not, check fuel pressure per the fsm cranking, and the MAP sensor. out put voltage key on, and cranking. and post that.
12. good luck.

get the engine to run on test fuel first. this saves big time labor
down time, and wasted parts , guessed at)

doing a real tuneup , is not ever a waste.
a tuned up engine pays back in lower gas costs. big time.
fuel is expensive.

sounds like a few things, bad/fouled spark plug,old/clogged fuel filter/old air filter or bad fuel. When taking bikes out of storage bikes often suffer from this problem from old fuel sitting in bike gumming it up.

Sounds like a timing issue or simply bD spark plugs. Do a spark check and see if you have a kice blue arc on the plugs. Also I've seen the flywheel key break on those before. That situation will greatly affect the timing Nd cause back firing also check your valve clearance.

If the timing is right and you have spark, then it could only be a fuel issue. Does it have enough fuel getting to it? Have you checked the needle and seat in the carbs for wear or debris. Try undoing the fuel bowl drain plug and let some fuel out, if nothing comes out, try turning your fuel on. If on, and it is a vacuum tap. Check that you are getting good vacuum for the fuel to come out. If it is a gravity feed, take the hose off the carb and turn tap on to see if enough fuel is running out.

try starting meaning pull the rope 6 times and then check the spark plug if its wet clean it or try a new plug, if its dry your not getting fuel in the cylinder which means carb problems. if you have a seringe or something to put some gas into the spark plug hole then install spark plug and try it. if it runs for a couple of seconds then you need to focus on the carb. only put a small amount of fuel in the plug hole if you try it otherwise youll be pulling on the rope for awhile before it will start. hope this helps.

Turn the key to run and listen for fuel pump in the gas tank to run you should hear a buzzing noise that should only last 3 to 5 seconds then will shut off until you try to start. You should also hear the fuel pump relay click off under the hood. If fuel pump is good you need to check for spark at one of the plugs.

Put in a new spark plug and check plug wire connections and ECM ground connections.

You probably have weak spark and when bump started the plug sparks strong enough to run the engine.

A weak battey can also cause this. Your ECM needs a minimum of 9V to work. (the ECM gives spark and timing) When kicking over, there is not enough volts to spark. When bumping over the alternator provides the extra volts to start the bike.

Hope this helps!
Rob

Stihl weedeater was running and stopped suddenly. Put in a new fuel filter and cleaner air filter with soap and water. Checked spark plug and it appeared fine. Started the weedeater, ran for a second or so and stopped. Spark plug wasn't gas fouled. Could it be the carburetor needing new diaphram gasket and spring.