Alien10

This is just a wild guess.. If you are certain the ignition system is OK and performing consistently, I'd suspect something in the fuel had gotten into the injector and caused the run issues. I've read where some Hisuns were produced and sold without an in-line fuel filter ahead of the injector, and that these injectors are very sensitive to unclean fuel, acting up with odd running symptoms, or no starts. Could be yours just managed to digest whatever was in there and now has returned to normal. You might just order a standby injector in case the issue returns. Congrats on getting back on the road!

Hey, congrats on the repair!

Looking at the pics, I think the 500 and 550 beds are the same. My 550 has I think 6 attachment screws/bolts to hold that side panel in place. Pop Bob has described their locations. Mine has two in the upper side panel, see pic below (stolen from Pop Bob) to hold the panel to the black top cap and rail piece. These are hex cap bolts. You can see in his pic that the side panel's tabs fit behind the top cap and those cap screws pull the side panel up tight to the inside of the top cap. Otherwise, on my side panel there are two phillips heads at the front of the side panel, one at the rear upper side panel, and one on the bottom of the side panel toward the rear. I flexed the bottom edge of my side panel where it wraps under the bed and the mud guard moved a bit with it. So the mud guard screws don't appear to be holding anything except holding the mud guard itself to the side panel. No need to remove those as Pop Bob said.

Pop Bob, Great pics! thanks for posting them along with the text comments. It is super helpful to know that those are the fasteners to remove the side panel and get at the latch bolts and I'd guess the tail light also. Thanks!!!

If you do try to start removing panels, I'd recommend that the first step would be to take a pick and completely clean out those phillips screw heads so they don't strip out, and use a big enough phillips bit to fully engage the screw head. (Don't ask why I make this recommendation).

Sounds like the no seat belt limiter kicked in and stuck. If you fasten the belt will it start and run?

Ya, that would be my concern too, damaging the light assembly. Did I mention how I hate those "nut clips"? They fall off and are lost forever. Probably OK for the production line but removal and maintenance, they are horrible. If you have any luck at all, please consider posting your results, it sounds like it could be valuable to other Coleman/Hisun owners. Good luck to ya.

Those stupid smiley faces are supposed to be "C" Thanks to auto fill or some AI crap.

I would never recommend this.... but....... what if you drilled two 3/4" holes in the fender side directly opposite of where the latch bolt heads are? There are real down sides to trying it: A: You have holes to plug or cover up some how. B: there might be something inside that is blocking access to the heads of the latch bolts after drilling the holes. 😄 You hit a tail light wire with the drill. Possible resulting actions: A: Rubber grommets are available in common sizes to plug holes.... B: If B is the case, you're sort of screwed, and back to square one. 😄 See action "B" directly above. Under questioning, I'll deny ever mentioning any of this.

While stacking fire wood, I was looking at my dump box. There are screws along the bottom and at the front of the side panel that hold the side panel in place, but there is also the top plates (#11 in the diagram) that have to come off. There may be some side plate screws hiding under those. (See Note below) Not sure if there are any side panel screws under the fender lip extension, it doesn't really appear to be so, but hard to tell from the diagram and they aren't visible on mine. Hopefully, if you can find and remove the side plate screws, including any under the steel top plate, maybe you can pull the side panel away enough to access the latch bolts. Note: In the diagram, #3 are those annoying thread clips that the screws go into. My experience with those on other machines is they tend to fall off when the screws are removed and drop out of site or into a crevice that is inaccessible. So beware of those. Again, maybe just removing the rear and bottom screws for the side panel will let you get behind it to the latch bolts. What a nightmare design!

Man, I agree with Pop Bob that it is likely the injector. Some Hisuns were manufactured and sold without an in line fuel filter. There have been several videos on line of folks suffering from the resulting clogged or malfunctioning injectors. They simply do not like anything in the fuel they are spraying. Adding an in line fuel filter is easy, and an absolute must.

Ya, looks like you gonna have to get behind that mounting somehow to reach the bolts.

Yes, they are not the most user friendly assemblies nor are the diagrams. While there is a section on "removing the bed" they seem to have completely neglected to insert any text to that effect. Wonderful! Are your latches damaged? If they are just jammed up, try to use a pressure washer or hard stream from a hose to flush them out. Follow that with liberal doses of WD40. Working them best you can to free them up.

Slightly enlarged view of the bed arrangement. Hoping these are of some help.

These diagrams are a little vague but maybe can shed some light on how the bed box is assembled?