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Discussion Starter · #1 ·
New to the forum and first Kawasaki. Thanks for the help in advance.

I have a 2019 Brute force 750 that will idle but when given any bit of throttle it dies. Before it started this problem it was a dog and wouldn’t go over 30mph.

The bike has around 4000 miles and its

Here is what I have done so far...

Both cylinders have spark

both injectors are spraying fuel

Timing is on point with both

I adjusted the valves

Both cylinders are at 120psi on the compression test.

I put a new battery in it.

No check engine lights are on.

the gas is new.

The spark plugs look good but I ordered new ones. ( Not installed yet )

There are no check engine lights on

I pulled the muffler off to make sure it wasn’t packed with carbon build up creating excessive back pressure.


Any ideas????
 

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120psi compression is in error. The compression releases shouldn't allow that to exceed about 88psi during cranking. (54-88 is norm per the manual.) The only other time it won't be this is when the valve timing is off...as in jumped time or both comp releases have lost their springs. Next, better test the fuel pressure. It shouldn't be less then 43psi at idle.
 

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Discussion Starter · #3 ·
The timing is on for sure. The first cycle it shows around 75psi and the second time around it goes up to 120psi.

I’m going to throw a fuel pump in it and see what happens.

Thanks -Evan
 

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Ok so backtrack. When you started having problems when it wouldn’t go over 30 what did you do? Anything happen to the machine? Deep water, overheat, sit for a long time?
Maybe have bad gas?
 

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Discussion Starter · #6 ·
No, nothing out of the ordinary and It’s never been in deep water. When it began acting sluggish and wouldn’t go over 30mph it felt like there was an exhaust brake or some sort of back pressure because it would decelerate fast when I let off the throttle. I was riding and it died, after that it would only start and idle but with any throttle it would die.
 

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Discussion Starter · #7 ·
I agree that would be the thing to do but I’m out of town for a few days so I can’t test it. I bought the pump online so should have an answer by this weekend.
 

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Any luck? I’m thinking you might have to take it in and run diagnostics. A lot more sensors and o2 stuff on these bikes than the old ones. I’m sure a dealer can hook it up to their computer
 

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Discussion Starter · #11 · (Edited)
Update: It won’t start now. Installed new plugs and the fuel pump with no change, still won’t start. Chased wires- look fine.

Emptied tank and put in fresh gas again. Purged fuel line at intake of old fuel.

still have spark, injectors are opening, double checked timing.

I ordered a scanner so we will see if it’s faulting.
 

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Discussion Starter · #12 ·
Scanned it, nothing faulting.

I drained the oil and found quit a bit of aluminum.

long story short: The connecting rod inserts are trashed (see picture). It looks like I can polish the crankshaft and put it back together with new connecting rods.

This should explain the gradual loss in power/ function, the engine was binding more as the inserts got progressively worse.

The strange part is it never made any noise indicating this issue... I had a Honda rancher do this to me before and it sounded like a tongue click.
Grille Automotive tire Hood Automotive lighting Motor vehicle
 
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