Hisun Axis 500 Problems - Hesitation, struggles to go up incline, and low speed regardless of gear range

[AlphaSerenity]

Hello,

Before I invest $10k+ into a brand new UTV for the farm, I want to get my feet wet with a fixer upper and learn the mechanical side of things. I acquired a 2022 Hisun Axis 500 (Lowes-specific model) from an auction for $500. It has only 200 hours and 120 miles on the engine. It looks like the previous owner used it for ranch work and didn't drive it on trails, deep water/mud, or anything too crazy.

While it runs and moves, it has some problems. It struggles to accelerate up any incline in high and low range and sometimes stalls when I let off of the throttle or change gears. When I apply throttle in neutral, it sounds like it is struggling for fuel/air and pops. When I decelerate, there is a grinding sound coming from the clutch, which I've read to be related to the one way bearing and is semi-common. The last thing I've observed is sometimes the speedometer display sometimes will show a much higher value for a few seconds after barely touching the throttle. Based on the documentation, if a problem is detected from the sensors, the instrument panel display should have an error code rendered on the screen in place of the time, but this isn't happening. Here is a video showing some of these issues (engine is exposed with console removed):

https://www.youtube.com/watch?v=FFAkO5TaGps

 

Here is another video of the clutches in action:

 

I've done some research, but information on this specific unit and sister units is limited. There does seem to be transmission and clutch issues reported. I still need to check into the head gaskets. I don't have the equipment to test compression right now, but I do plan on ordering what is needed soon. I do have an order in place for some cables to read the diagnostics from the computer. There is a shop two hours away from me that works on Hisun products, but I am hoping the problem can be identified and is something within my ability to handle. Below is what I've already investigated.  I am leaning towards the primary clutch needing replacement right now.

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After getting it home and unloaded, I did the following maintenance/checks to it prior to operating it further:

1. Changed the engine/clutch oil (and filter) and gear oils using manufacture recommended viscosity
2. Changed the air filter and checked for cracks in the air intake flow. Verified good suction.
3. Cleaned the throttle body
4. Changed the spark plug and verified the gap was within spec (0.6-0.7mm)
5. Changed the coil and coil wire
6. Changed the fuel lines, fuel injector, and verified the fuel pump was outputting the correct initial prime pressure for ignition and continuous pressure after ignition. Also completely emptied the fuel tank and made sure octane 91+ fuel is being used per manufacturer specs. Ran seafoam through system too.
7. Cleaned the spark arrester and verified no cracks or gaps in the exhaust flow
8. Changed out the O2 sensor
9. Checked all wired connections to ensure they were secured and no breaks were visible
10. Checked the belt for tightness and for any signs of wear and tear
11. Verified 4WD and the differential lock function as expected - still hesitates and struggles uphill
12. Verified the fan gears in the shifter are not corroded and working as expected
13. ECU was reset after replacing sensors and fuel-related parts

 

 

Thanks!

[Greg Kilgore]

Welcome to the forum.

Sounds like you hit everything and then some. The only thing I didn't see was adjust the valves. And fuel filter.

 

my fuel filter looked as if the ends where the hoses connect had been dipped in paint. Then the fuel caused the paint to flake off. Had some rather large paint chips come out of factor filter after only a few hundred miles. I replaced and got a new injector but haven't replaced the injector yet. That was literally 1000 miles ago.

Only major issue I've had with mine was the rear driveshaft. The part on the engine/transmission that the driveshaft attaches to is referred to as a cup. The rear driveshaft has splines that slides into the cup. The splines in cup and on the shaft chewed up. But was able to put in 4 wheel drive to limp back home. Was quicker to get replacement parts off Amazon then wait for the mobile tech.

 

That was at the 500ish mile mark and I've got over 2500 now. Mostly 1 lane blacktop and dirt/gravel road. But a little off-road trails. Nothing too ridiculous. Wife doesn't like off-roading. 

 

Hope you get it figured out.

 

[Old Outlaw]

Mine did the same thing and I changed out the injector. (easy) It now runs better than ever.

[AlphaSerenity]

I did change out the fuel filter and injector, but the problem remained.  I have also replaced the wet clutch and discovered some of the rollers were out of their slots in addition to the one way bearing being bad.  I am picking up some gauges today to check into the valve clearance and adjust them if needed.

[aefron88]

I would adjust valve lash, and drain and fill the fuel, as it is likely stale if it's been sitting and may have a pocket of water at the bottom of the tank.

[Michele]

I'm having a similar issue with my Axis 500.  It seems to bog down and struggle, particularly on inclines/hills (see video).  Frustratingly, it also only happens intermittently, more often when the machine has been running for a while (I use it for farm work only).  So far I have:

1. Replaced fuel filter
2. Replaced fuel injector
3. Replaced MAP sensor (reset ECU after)
4. Replaced spark plug
5. Verified air filter is clean
6. Verified no obstructions in exhaust
7. I only run it on 91+ gas and put a can of seafoam through it to no avail

I did previously have an issue with a failed one-way bearing, but this particular issue predates that failure.  I replaced the one-way bearing a few months ago and inspected the wet clutch, primary/secondary clutches and belt while I was in there-didn't see anything of concern.  Where do I go from here?

[Greg Kilgore]

Couldn't tell a lot from video.

Did sound like a little bit of a miss.

In the dark check to see if the plug wire is arcing. Check connections for coil and spark plug. Maybe check and re-gap the spark plug.

Good luck and keep us informed.

[Erichisun]

Did you ever fix this problem mine is doing same thing and ive replaced everything as you did   please help

[Michele]

My problem ended up being the Oxygen sensor. Initially I had just cleaned it but then I changed it out completely and reset the ECU. Haven’t had an issue since

[Bubba]

Not trying to be smart but I didn’t see anyone mention the simplest thing. Only trying to help but I’ve seen many machines run poorly because the seat belts must be latched, js.

[Alien10]

Bubba, I thought the same thing.  But disabling high speed without the seat belt buckled is in the manual and on a dash board sticker. 

[AlphaSerenity]

I am still having this issue and have already replaced the oxygen sensor.  I am about to just put it in an auction or FB marketplace and try to get my investment back at least.  That being said, someone did mention where I got the oxygen sensor, that they had to go through three of them to get one that was working.  I will try one more time to replace that from a different part supplier and see what happens.

 

[Bubba]

Sounds like an exhaust leak but you said you checked that. I bet you have a clogged fuel injector. Easy to replace if that doesn’t work and since you have checked almost everything, sell it or let a service dealer look at it.

[Bubba]

9 hours ago, Alien10 said:

Bubba, I thought the same thing.  But disabling high speed without the seat belt buckled is in the manual and on a dash board sticker. 

That’s cool, didn’t know that, thanks. I didn’t see they mentioned checking the injector but they said they did. I believe they said they got a very good deal on this machine. If so, since they’ve basically checked everything they could, Maybe letting a service dealer take a look???