2010 Mud Pro 700 Wont Start

[Kuzko]

My brother has a new lawn ornament. Always ran great up until it sat on trailer for period of time waiting for decent weather. To get it started all I simple have to do is choke the throttle body with my palm. That's right choking a EFI engine into starting is wonderful. Will run all day long till shut-off than have to drag it home. There no mods to the bike other than stock from dealer. He's trying to avoid spending more $$$$ at dealership.

So far have checked and confirmed
Fuel pump - Has required amount of pressure and does not back feed into the tank (leak test confirmed that)
TPS - Set TPS to the correct setting on display
Battery - Brand new and fully charged. Bought new one as per stealer ship -$$$$
Map Sensor - Dealer replaced after 3 days ownership. No codes shown but dealer said to try replacing it again so -$$$$
Air Box Sensor - Replaced it as per stealer ship -$$$$
Air Lines / Snorkel - Everything checks out fine
Wiring Harness - No signs of wear like other threads have said about terrible problems with them

What left ? Starter / Stator ? Be nice to get this fixed rather than watching it sit there. Damn shame.

 

[Trashy]

Compression?

 

[Murminator]

My non efi grizzly did that used to shove a glove in it would always spit fuel back into filter and saturate filter so it was like it was always flooded always fought with it but when it was warm was fine rebuilt carb twice still same until I gave it a valve set now no issues at all. Intake valve opens to early not keeping enough compression to fire. My buddys non efi grizzly was starting to do same valve set fixed it also.

 

[doorfx]

I know it sounds crazy but put a new plug in it. Also make sure your coil wire and cap have not come loose. When you say airbox sensor are you referring to the IAT sensor ? You also have an ISC sensor and Motor. If it is not working it won't close so allows to much air. Does it idle rough ?

 

[gordhunt]

Probably got water in the spark plug boot area seen that on my friends a few times. Once its fixed I'd sell it and get something reliable we have two of that model as our fire dept quads and they are junk imo

Sent from my LG-D803 using Tapatalk

 

[QMAO]

possibly dirty injector?

 

[Kuzko]

Thanks everyone. Im leaning towards it being something do with compression. Gonna try going tighter on the valves. New plug was installed and was no difference. Same as injector I thought it could been but it fine when it is running no rough idle just smooth running. Read somewhere the decomp springs do wear out. Once it is running he for sure trade it in. My 09 brute been running problem free since 09.

 

[tool_man]

Did you check the rubber boot to the throttle body? I've had a couple crack now, and I believe there was a recall on them. I even keep a spare in my toolbox. Might not be related, but wouldn't hurt to check.

 

[Kuzko]

The boot was good. I even took it off to be certain.

 

[nbrecht]

Does it have a silver fuel filter in the back right wheel well. My 09 had one and I started have problems with no start or just shut off. I pulled the filter and never had a problem since.

 

[Gibraltard]

Good day. Anny update ? I have the same atv whit the exact same problem. Fuel pressure is at 40 psi. Fuel volume is more than enough. Did clean the injectors whit high pressure system (OTC 7000A) atv run smooter but stil no start when cold (first start of the day) after work i will check compression but I douht it.
Regards Patrick (sorry for my english)

 

[Gibraltard]

Test.. Did post respons.. Dont see it

 

[Gibraltard]

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May 2018
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Re: 2010 Mud Pro 700 Wont Start
Good day. Anny update ? I have the same atv whit the exact same problem. Fuel pressure is at 40 psi. Fuel volume is more than enough. Did clean the injectors whit high pressure system (OTC 7000A) atv run smooter but stil no start when cold (first start of the day) after work i will check compression but I douht it.
Regards Patrick (sorry for my english)

 

[doorfx]

Service manual calls for 43 psi minimum constant pressure. You can download a free service manual at countrycat.com under technical. It will give you the test procedures.

 

[doorfx]

Problem free 700