Yeah that's my fault on the year, I was talking about my 2021 in another forum and accidentally put the year here. I'll edit the title, it's actually a 2007 that I'm working on in THIS thread. Again, my fault. I got my wires crossed. Pun definitely intended. So does that change anything in your original train of thought? I want to pull the side off tomorrow and do some stator and pickup coil testing. Not sure what I'd be looking for but I'll start by ohming some things out per the manual.

Well..yeah..it makes all the difference. I have the 07-09 service manual and it does have the wiring diagram...page 11-28. Link below. Do the same testing...and do start with that engine speed sensor...AKA CPS.

https://acrobat.adobe.com/id/urn:aaid:sc:VA6C2:f84e505c-033c-48bb-8ffd-d627883cb07b

Been working, sorry for the late reply. Many thanks!!

Sorry, I don't have one.

Let me ask you this, then since I can't find the wiring maybe you can help me troubleshoot. I have 22.5 volts NEGATIVE coming out of the cdi into the coil. First, 22v shouldn't be possible since my battery is holding a normal 12.4v, second...negative volts?? It's like it's telling me I've got my voltmeter leads backwards but I definitely don't. Thoughts? Bad cdi?

First let's say that only carbed machines have CDIs and fuel injected engines have ECUs or ECMs. I think the 21 500 is EFI. Correctly me if I'm wrong. Next, it will be the CPS or engin speed sensor that triggers either to either send a 12 volt pulse to the coil or close the ground to allow it to charge. I always though it was the later but I found on Kawasaki I was wrong..in that the coils on there machines are hard ground wired and the CDI/ECU sends 12 volts to the coil. This is a millisecond and when it ends the field collapses and generates the spark as it discharges. So, with it just sitting there not running the field coils MAY be giving you a bad reading..just because only an active coil can give you voltage reading higher then the source battery. It may also be that CFM uses the ground to trigger the coils. Anyway I do have the 2020 CForce 450 wiring diagram and I am willing to bet there are a great many similarities. That link is below and will ne available for 48 hours before it expires. You are welcome to it. I think you are going to find a bad engine speed sensor(common problem) or ECU or roll-over or AUX relay...or just a bad key switch like so many others have had. Electronics are not the Chinese strong suit. I would pull the engine speed sensor first and inspect the bottom for trash. It should also be ohm tested as per the manual as well.

https://acrobat.adobe.com/id/urn:aaid:sc:VA6C2:c08d7ca6-d487-4944-8508-7b296d0768a6

   

Yeah that's my fault on the year, I was talking about my 2021 in another forum and accidentally put the year here. I'll edit the title, it's actually a 2007 that I'm working on in THIS thread. Again, my fault. I got my wires crossed. Pun definitely intended. So does that change anything in your original train of thought? I want to pull the side off tomorrow and do some stator and pickup coil testing. Not sure what I'd be looking for but I'll start by ohming some things out per the manual.

Sorry, I don't have one.

Let me ask you this, then since I can't find the wiring maybe you can help me troubleshoot. I have 22.5 volts NEGATIVE coming out of the cdi into the coil. First, 22v shouldn't be possible since my battery is holding a normal 12.4v, second...negative volts?? It's like it's telling me I've got my voltmeter leads backwards but I definitely don't. Thoughts? Bad cdi?

Sorry, I don't have one.

Okay thanks!

I'm trying to troubleshoot an issue, does anyone have a link to the wiring diagram for a 2021 cforce 500? Thanks!

Very strange.Do these have a vehicle down/roll-over sensor?

That was my first thought, too because my raptor 700 has one. I'm still trying to find that answer but I have to wait until another day off. I work a weird schedule and the shifts are 12.5 hrs, then cook for the kids, homework, etc lol it's a long day on my work days. Weird how it'll do it on flat ground riding OR sitting still revving but does it worse uphill.

Wouldn't think anything electrically or mechanically would change on position but fuel demand will change with load and throttle position and fluid position will change with different angles. Wondering if it's fuel supply related...as in water in the tank...or pickup sock/filter blocked...or secondary filter issue if it has one. Think I'd run some pressure and flow rate tests..maybe drain the tank..pull the pump and check the filters...ect

I was off today and had some time to tinker and finally got a check engine code to flash! That helps narrow this down a lot. After hooking up my OBDii scanner i got P0261 which is cylinder 1 injector malfunction. So as of now I'm going for a dead or dying injector. During my tinkering it stopped firing up all together. Then I'd clear the code and fire it up, it'd run for 30 seconds or so and stumble out then die. That actually sounds more fuel pump related but I'm hoping the pump is fine and I can just clean or order a new injector and go with that. Either way, replacinging both would be right near 100 bucks which is A-okay with me.

Got a day off work and put 12v to the injector, added carb cleaner to the inlet, then 60psi of air. Mist only came out of 2/4 holes. Added 120psi air and mist came out of 4/4. EFI light problem fixed. Totally unrelated to the built up pressure, however, the canister is now deleted AND I removed 1 left and 1 right side front inner fender plastic for air flow AND I added a 12v dc waterproof fan and zip tied it to the frame right in front of the head aiming the airflow back towards the rear. This flow also goes across the bottom of the tank. Surely the combination of those 3 things will drastically reduce the under-tank heat and allow it to be pushed out of the rear. Time will tell. Thank you for sticking with me through this and offering your knowledge.

Very strange.Do these have a vehicle down/roll-over sensor?

That was my first thought, too because my raptor 700 has one. I'm still trying to find that answer but I have to wait until another day off. I work a weird schedule and the shifts are 12.5 hrs, then cook for the kids, homework, etc lol it's a long day on my work days. Weird how it'll do it on flat ground riding OR sitting still revving but does it worse uphill.

Wouldn't think anything electrically or mechanically would change on position but fuel demand will change with load and throttle position and fluid position will change with different angles. Wondering if it's fuel supply related...as in water in the tank...or pickup sock/filter blocked...or secondary filter issue if it has one. Think I'd run some pressure and flow rate tests..maybe drain the tank..pull the pump and check the filters...ect

I was off today and had some time to tinker and finally got a check engine code to flash! That helps narrow this down a lot. After hooking up my OBDii scanner i got P0261 which is cylinder 1 injector malfunction. So as of now I'm going for a dead or dying injector. During my tinkering it stopped firing up all together. Then I'd clear the code and fire it up, it'd run for 30 seconds or so and stumble out then die. That actually sounds more fuel pump related but I'm hoping the pump is fine and I can just clean or order a new injector and go with that. Either way, replacinging both would be right near 100 bucks which is A-okay with me.

Very strange.Do these have a vehicle down/roll-over sensor?

That was my first thought, too because my raptor 700 has one. I'm still trying to find that answer but I have to wait until another day off. I work a weird schedule and the shifts are 12.5 hrs, then cook for the kids, homework, etc lol it's a long day on my work days. Weird how it'll do it on flat ground riding OR sitting still revving but does it worse uphill.

The evap system takes gasoline fumes from the tank and recycles it through an EGR system. There has been some issues with it but not sure any relate to the problem you said you are having..which sounds more like vapor-locking or low fuel pressure from excessive trapped heat.

And another thing: when we were trail riding last weekend I only got the stalling/efi light to happen 6 or 8 times all day BUT 5 of those times I was tilted nose-up going up a hill. So I ran a little test on the creek bank at home and determined that you can consistently make this issue happen when giving the atv throttle while tilted uphill. So much so that it would even stall completely out. Normally when it acts up it don't stall all the way out, just enough to slow you down a bit.

The evap system takes gasoline fumes from the tank and recycles it through an EGR system. There has been some issues with it but not sure any relate to the problem you said you are having..which sounds more like vapor-locking or low fuel pressure from excessive trapped heat.

New news on my issue. I removed the evap garbage as per instructed from a couple different youtube videos. Pretty straightforward, plug off the line into the throttlebody, route the tank vent somewhere it can safely puke if it has to, and physically remove the canister if you don't want it in the way. Quick and painless. However, it didn't help. Also I wanted to mention that this issue of the efi light coming on and the atv stalling for a split second doesn't only happen when the tank gets hot. I can crank it up from cold, put it in gear, take off, and immediately start getting the stalling. Maybe I'll upload a YouTube video so I can show you exactly what's happening because it's very mind boggling. It'll also do the same thing in park or neutral if you just rev it up. I've seen videos of people hitting rev limiters or "fuel cuts" on these. Mine don't get that far before seeing the efi light. It's like it's starts starving for fuel so it throws an efi light which stalls the engine then picks right back up like nothing happened. Weird.

The older Yamaha Grizzlies also had this problem and they just made a vented side cover plastic piece for both sides. Not sure if we can do that here but seems like a small like 3-4" fan mounded in the right spot could help a lot. Something like one of these with protective grills tapped into keyed power:

https://www.amazon.com/GDSTIME-80mm-25mm-Brushless-Cooling/dp/B00N1Y50QQ/ref=sr_1_6?crid=698QUJMO1PPM&dib=eyJ2IjoiMSJ9.O4fPJNyA-FKjFcK5KiWEm6PSu3ESjsdfhvu4pX5SMjlFpFQtNptce7n2872nUT23-ctzr3WQROcOXqz6e8Mn72kDtwbtyxX8-gjoOVT9m6crpstU37zJ1n2sSZJgpSc0wySG0aSBen5nRLNmv9Y_AwEHRlx87bwuIAUKHNhLDp474bHKIbMjdQmsaaN8ztBos_9ZsVntFZz1QRHYxDJ_dDF35n1cedzbpZ_EJ27HwJ0.sbH-O3bMQdiZeOPwliJxgGTZKlNt_9V-fogYHQb0Cww&dib_tag=se&keywords=4%22+dc+fan&qid=1725122372&sprefix=4+dc+fan%2Caps%2C135&sr=8-6

Okay I've finished my night shifts and got to tearing the plastics down. The youtube video I watched prior to making this post showed a vapor canister in the rear storage but mine did not have this leading me to believe I didn't have one or it was deleted. Turns out, on my model they are in the front tucked behind the left front wheel. Are there decent instructions that you've seen to delete this? I don't want to blindly follow just any ol' write up. I'd rather have one with credibility. Thanks for all of your advice so far!

If the heat under the tank is enough to boil the fuel, then it is enough to do the same in the line leading to the injector..we call that vapor-locking. And is not unheard of on these. Need more heat shield on the line and tank bottom as well as more air flow in that area.

I've searched around to see if I could find what people are doing for better airflow on these and am not having much luck. Short of just maybe removing some inner fender plastic and cutting out a piece on the side plastics near the shifter then the same on the other side....I don't know.

If it has the fuel vaporization system,look to an issue with water in the canister or a sticking EGR or other valve. Do the delete if you can...it's helped many people.

Mine doesn't have a canister in the rear compartment like I seen on a YouTube video. Maybe they fixed that or it's been deleted. Also, with further testing it seems that taking the fuel cap off DOES appear to stop the issue from occurring. I also noticed (and took a video) of bubbles in the tank...excessive bubbles. I'm assuming from boiling? That's a little concerning.

If it has the fuel vaporization system,look to an issue with water in the canister or a sticking EGR or other valve. Do the delete if you can...it's helped many people.

I'll dig into that this weekend, thanks for the information!

This issue can happen at any time it seems like. Here's what happens. I'll be cruising at any speed and suddenly the atv will just act like you've pushed the kill switch. The lights on the dash stay on but it immediately starts to bog down as if you've completely let off the gas. When this happens the efi fault (red light on dash) comes on. This whole thing only last half or 3/4s of a second. Just enough to slow you down from say 25 mph to 23 or 24 then the atv picks right back up where it left off and you're back up to speed. It'll sometimes do it once every 10 seconds, sometimes once every 30 seconds, sometimes not for 30 minutes. And then it'll stop and not do it for an hour sometimes. Makes me think of a short in wiring? Another thing, my fuel gauge doesn't seem accurate and my tank builds up pressure and "whooshes" when you Crack the cap. I've seen a tank pressure fix video on YouTube so maybe that'll fix that issue but I wondered if they were related. I drove around carefully with the gas cap off but it still did the intermittent efi fault. Any help is appreciated!

Pressure in the tank is normal unless it's so hot it's boiling...which it can under certain conditions. Your issue sounds more like a fuel related problem. This can commonly be from three possibilities. One-the fuel pump is failing and loosing pressure or can not supply full pressure under load. Two-there is water or dust in the tank preventing flow through the pickup or the filter has water or rash in it. Or three-the heat is causing vapor locking. This happens more then one would think. CFM has had issues with this on the CForces for a while. The cure is to wrap and place heat guards on the fuel supply line to the the injector(s). If your issue happens more after it warms-up, this might be a consideration. Otherwise you need to rear the code when the MIL light is flashing to know where the problem is. The other thing it may be is low voltage to the coil or system but that could mean a failing charging system or battery...or some corroded connector somewhere. Have to do some testing to narrow it down.   

Sorry, I didn't get a notification that you replied to my post. Thanks for the reply. After further test I have found that I get pressure in the tank 75% of the time. It weird to me that it doesn't happen all the time. Maybe that little valve in the cap is failing, I don't know. The pressure is so extreme that when I unscrew the cap, I can visually see the plastic draw inward a quarter inch, that seems excessive. However, driving with the cap loosened didn't help my problem. Next, I found out how to consistently get the issue to happen and that's to be at an uphill angle. If I'm going up a hill that's kind of steep, it's guaranteed to cut out and flash that red light more than once. It's never bad enough to kill the engine but it's bad enough to make you lose momentum and/or traction. Also, I wanna mention that there is no check engine light on or any codes like you mentioned. The charging system is doing it's job as well and the battery is maintaining as intended. More testing to come. Thoughts?