# 2019 Brute Force 750 having wierd idle stall.



## Doashep (Feb 12, 2020)

I bought my brute last January brand new from the dealer. Ran to the first service interval and did a full service on it then snorkeled it soon after. Sometime shortly there after I got back to the house and was about to turn it off when it just died like I switched it off. I took it to the dealer since it was still under warranty and told them to check it over. I made sure to tell them to check the IAC, TPS, and CPS. Picked it up and they said the Air Filter was a little dry and it seemed to be running right. Got it home and took it for a run and sure enough when I come down to idle it will pretty consistently stall. Starts right back up with no issue. I've since added a full empire system and VFJ ECM flash. She still runs like a raped ape but will still stall when I come back to idle unless I bump the throttle a little bit. Has anyone ran into this or have any ideas?


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## Polaris425 (Dec 16, 2004)

Idle set too low?


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## Doashep (Feb 12, 2020)

See that I don't know. I'm thinking about bumping it up a bit. Have to pop the side cover off the throttle bodies. I'm just curious as to why it's doing it considering the IAC is controlled by the ecm


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## NMKawierider (Apr 11, 2009)

There have been some reports of problems with the Kawasaki IAC valves sticking or having electrical problems. Symptoms include rough or non consistant idle as well as not idling at all.


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## Doashep (Feb 12, 2020)

Yea go figure. Can you straight bypass it by putting the throttle body hoses together and manually setting idle?


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## NMKawierider (Apr 11, 2009)

Nope.


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## Doashep (Feb 12, 2020)

Any suggestions. Replace the valve? I've already tried cleaning it. I'm assuming it's working most the time since it does idle but stalls after running it hard and coming back to idle


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## Eryxian (Feb 8, 2020)

You changed the air intake and throttle curve, did you change the jets to compensate? 

If you change the exhaust as well your issue is only going to get worse. Adjusting the idle may help a bit, however your ideal is now likely higher than spec as you have changed your air-fuel mix. Adding the snorkel means that after extended running you are now preheating your intake air a few degrees. 



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## Doashep (Feb 12, 2020)

Efi machine. Been tuned to compensate for increased air flow but it did this before I changed exhaust and all.


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## Mechcondrid (Jun 2, 2020)

put it up on stands and pop your airbox cover off, start it up and run it WOT for a few minutes to get it nice and warm; basically try to get it to stall again.
if it does then ya something is up with the valves, since they are rubber hose you could try and run a "dumb" bypass with a smaller diameter pvc hose and a couple t barbs and a needle screw valve to each valve to try and "help" the valve by giving you some limited manual override of the air flow.

if it doesn't do it then could be something is not agreeing with the snorkle you have on there.


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## Kw1488 (Apr 23, 2021)

2008 brute 750 is popping out intake bike is stock half or 3/4 throttle starts surging like not getting fuel..bike has new wire harness, new fuel pump, fuel pump relay. Valves are good. Bike fires right up has 60psi on both cylinders


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## NMKawierider (Apr 11, 2009)

Kw1488 said:


> 2008 brute 750 is popping out intake bike is stock half or 3/4 throttle starts surging like not getting fuel..bike has new wire harness, new fuel pump, fuel pump relay. Valves are good. Bike fires right up has 60psi on both cylinders


If the valves & timing, compression and fuel pressure is OK like you say, then look to low coil voltage or failing pulse coil...or cracked TB boots.


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## Kw1488 (Apr 23, 2021)

Tested pickup coil its good no drops in voltage anywhere ...boots are good


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## Kw1488 (Apr 23, 2021)

When it's reving up and down there are no changes on meter of voltage problems


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## Mechcondrid (Jun 2, 2020)

Kw1488 said:


> 2008 brute 750 is popping out intake bike is stock half or 3/4 throttle starts surging like not getting fuel..bike has new wire harness, new fuel pump, fuel pump relay. Valves are good. Bike fires right up has 60psi on both cylinders


sort of sounds like you have back pressure on the inlets to the cylinder preventing the fuel from getting in fully.
maybe timing is off on the cylinder and its trying to pump in fuel a little late when the piston is on the up stroke?

if you can do it yourself, edit the throttle map and drop it down say 5 degrees or so just as a test and see if you still get it; if you don't then i'd check the timing to see if it's somehow shifted forward and pistons are now further into the cycle than they should be.


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