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Mule 4010's, 3010's and air-oil separators

465 Views 5 Replies 3 Participants Last post by  Zebrafive
I’ve got a new 4010 4x4. Some questions, but should be fairly easy ones.

I’ve read with interest the many posts on issues with 3010/4010 Mules idling/stalling/etc after xxx hours. After fuel system/electrical system/sensors trouble-shooting were eliminated as a possible cause, the gumming up of throttle bodies thought to be a direct result of the crankcase ventilation system seem to be a problem many have had. Seafoam etc. gives a temporary fix in many instances, eventually many posters note they removed the throttle body and gave it a thorough cleansing (and sometimes manually moved the throttle plate). Sometimes a Kawasaki dealer replaced their throttle body for free.

For those with older (pre-2014?) Mules, many people mention they’ve put an air-oil separator (aka catch can) on the line from the crankcase breather chamber, and then capped off where that line enters intake system immediately upstream of the throttle (Kawasaki calls where the crankcase vapors enter the intake system a DUCT p/n 14073-2100).

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Question #1: for those of you that have done this on any pre-2014 4010’s or any 3010, do you (a) vent the outlet from the catch can and also cap p/n 14073-2100 (i.e. an open system), or do you (b) route the catch can outlet back to p/n 14073-2100 (a closed system)?

Question #2: for those that have added catch cans and now have many additional hours on your Mule, do you think you’ve been able to eliminate or greatly postpone the throttle body gumming issue?

My new 4010’s crankcase vent system is a little different; on 4010’s since 2014 or so there’s an ‘extra’ air-oil separator (Kawasaki p/n 14069-0018) between the crankcase vent and where that vent line enters the intake system (this time a plastic Duct, p/n 14073-0784).

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Question #3: for those of you with 2015 or later 4010’s and have catch cans installed, do you (a) run the inlet to the catch can from the outlet of p/n 14069-0018 and then vent the catch can outlet / cap p/n 14073-0784, or (b) run the inlet to the catch can from the outlet of p/n 14069-0018 and then route the catch can outlet back to p/n 14073-0784?

Question #4: if anybody has done this, same question as #2 above.

I'm going to be adding a cheapo catch can as per question 3 (b), trying to be proactive, just wondering what success others may or may not have had with throttle gumming issues if you've also added catch cans.
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RE #3 I helped a friend yesterday do the install on a 2020 Mule 4010. His just came back from throttle body replacement under warranty.
We ran the included hose from the crankcase oil separator to the catch can and installed the small, included filter on the outlet of the catch can.
We capped the "nipple" on the air duct 14073B, it took a 9/16" cap.
I agree the included hose was very thin and came kinked the way it was packaged/bundled with a zip tie. We are hoping the kinks relax now it's installed.
We saved the hose P/N 92129A to reinstall if it goes in for service.
We had no idea what the "brillo" pad/ wad of curly mesh was for or where it was supposed to go.
We mounted the can with the included bracket under the seat.
He bought it in August 2020. Christmas of 2022, when he got home from Christmas travels it would not run right. It was running great when he left. He tried cleaning the air filter, replacing the fuel filter, and fresh gas. He was going to get new spark plugs next.
Another friend told him to remove the bottom plug from his muffler. He ruined it trying to get it out. I got it out for him. We replaced it with a stainless-steel plug instead of brass. We also used never-seize on the threads. It's a standard 3/8" pipe thread. He tried to buy a replacement from the dealer, and they could not find a listing for one in their parts book. They quoted him $125 to get it out.
End of March he decided to take it to the dealer. They cleaned the throttle body and no change, so next the replaced the throttle body.
He told me it had 200 hours.

That looks like the kit he bought. There was single hole in the sheet metal pan at the bottom of the frame, under the seat. We drilled a hole in the small leg of the "L" bracket. We drill another hole in the long leg of the L bracket to get the can higher.

We mounted the little filter on the "OUT" port of the can, not the top.
His hose came with single zip tie so tight it looked like bow-tie. If the kinks don't come out, he'll buy better hose.

Thanks for explanation of where to install the Brillo mesh pad. I hope he did not throw it away!
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