Need Some UTV Mechanical Advice (Rhino 700)

[J. W.]

Was given a Yamaha Rhino 700 FI that has been sitting in the weather and hasn’t been run in several years. I was told that when it was last run, the engine cranked fine, but would die when put into gear.

Trying to get the engine to crank, but no success yet.

What I’ve done so far (not much):

I replaced the ignition switch (key was lost).
I siphoned out the tank and put in fresh gas.
Battery is long since dead, but using my jeep as a jump, the starter turns and the coil seems good. It had decent spark when I pulled the plug and checked it. I changed the plug to new NGK anyway since I already had the original one out.

Piston is not seized. It has compression, but I don’t have a compression test kit handy to know how many psi. I don’t suspect any issues there anyway though.

I pulled the fuel hose off the fuel rail and checked for fuel flow. It spurts upon turning the key on and also when trying to start.

I did not pull the injector yet because it was getting dark before I got to that point. It could be that the injector is clogged or that there’s a problem on the electrical side (fuse or relay?), I guess.

I did notice that squirrels or rats or something have chewed the wires off what looks like an air temp sensor on the intake right before the throttle body. I assume it would still crank without that, but I’m not 100% sure.

Any shadetree (or pro) mechanics in the Hide? Would love to hear any other ideas on how to get this thing running.

These machines are old tech now in the side x side world and getting info on these things is kind of difficult.

 

[mtrmn]

Step 1, fix any and all wires on any and all sensors since this is fuel injected. A temp sensor will likely give a default reading of about 40* below when unplugged or the wires are missing. That don't play well with the computer when it tries to figure the proper fuel mixture.

If it has a dual throttle body like my Kawasaki mule, I'll have to write a book on that. One throttle plate is manual control, the second throttle plate is electronically positioned.

 

[mgoodrich]

The full service manual is available online for free.

I would start here for troubleshooting info.

https://www.rhinoforums.net/threads/2008-service-repair-manual-for-700-efi.8803/page-10

 

[J. W.]

Step 1, fix any and all wires on any and all sensors since this is fuel injected. A temp sensor will likely give a default reading of about 40* below when unplugged or the wires are missing. That don't play well with the computer when it tries to figure the proper fuel mixture.

If it has a dual throttle body like my Kawasaki mule, I'll have to write a book on that. One throttle plate is manual control, the second throttle plate is electronically positioned.

Copy that. The one on the intake is the only one I see like that, but I really need to take plastic off and wash this thing down to see.

 

[J. W.]

The full service manual is available online for free.

I would start here for troubleshooting info.

https://www.rhinoforums.net/threads/2008-service-repair-manual-for-700-efi.8803/page-10

Thanks, I have it. I’m looking through it now, actually. Problem is that the troubleshooting section relies on the assumption that the display (which shows diagnostic codes) works. Mine does not.
I’m kind of leaning towards buying the whole damn electrical harness to get the display and any sensor wires back up and running.

 

[mtrmn]

Thanks, I have it. I’m looking through it now, actually. Problem is that the troubleshooting section relies on the assumption that the display (which shows diagnostic codes) works. Mine does not.
I’m kind of leaning towards buying the whole damn electrical harness to get the display and any sensor wires back up and running.

If the diagnostic system doesn't work, it could be as simple as a blown fuse somewhere. And grounds are just as important as hot wires , make sure they are ALL clean and tight.

 

[mtrmn]

Also, if the diagnostic system doesn't work, It's very likely NONE of the fuel injection system works. IF it was "runnin' fine when I parked it" then the problem is more likely to have occurred during the time it was "settin' up". Like the aforementioned rodent chewed wiring.

 

[chevy_man]

If that's a MAF sensor it won't even attempt to start.

Time for a fine tooth comb over the wiring. It's likely the display will work once you fix all the problems in the harness.

 

[J. W.]

If that's a MAF sensor it won't even attempt to start.

Time for a fine tooth comb over the wiring. It's likely the display will work once you fix all the problems in the harness.

It’s not a MAF sensor. After looking at the repair manual, it is indeed a temp sensor. Engine should run without it, but it doesn’t say how well. Apparently there is no MAF sensor on this thing. At least not that I see in the diagrams. I’ll give it another look when I get off work today. It does have an intake pressure (MAP) sensor. I guess it gauges airflow just with that. It’s a weird (at least to me) EFI setup.

 

[roostercogburn98]

Check your emergency brake cutoff as well, my gator 660 won’t start if the e brake is off and I don’t have my foot on the brake