2007 grizzly 700...barely runs!!!why???

[luckylogger666]

hello to all
i need some help with my 2007 grizzly 700.
it has 190 hours on it. recently it has developed a major problem.
it has been to the dealer and they have NEVER seen this problem before.
here goes:
bike starts and idles fine
when in you slowly start giving it throttle, the bike runs rough and stumbles at about 1500 rpm and up.
if you pin the throttle fast, it revs fine up to red line
if you try to stop mid way between idle and redline is runs like crap

i have done everything possible. i even borrowed a buddies 2007 700 and swapped all the sensors, throttle body assembly, fuel tank with fuel pump, coil and plug wire, computers, etc.
i even pulled my head off and got it cleaned and re-done hopeing that helped
notta.
no codes come up on the computer.
ive changed plugs a zillion times
the engine compression test was great.leak down great.
with the stock computer in the bike the problem is less noticable but there

running the vdi copperhead, the problem is WAAAAYY more noticable.
ive had the copperhead in for a while and no problems before.
with way more spark output, i thing any problem with the grizzly will be amplified with the copperhead
lyle at vdi sent me a new copperhead in case it was it.
notta.
tryed all vdi maps for lean settings, rich settings,etc
no difference
ive concluded the engine is fine
the motor needs air fuel and spark
air should be fine
so either the spark of fuel is my problem im guessing
this battle is ongoing for months
any help would be great
im ready to kick it off a cliff!!!!

 

[luckylogger666]

thanks, the dealer had switched plugs.
i will check the gap tomorow to be sure
thanks

 

[gforce]

check to see how well the wires are on the coil..make sure the wire is connecting(the center of the wire) it might not be in the,,might have to cut an 1/8 of an inch off the wire....could a mouse have made a house in yer exaust pipe..??.

 

[luckylogger666]

hey guys
ive run the bike without the pipe and still runs rough
i swapped coils with my buddies 2008 and no differnce
i will keep checking and report back
thanks

 

[scoobienorth]

if you were swapping sensors on the throttle body this could be it, we chased this down for 3 months last year on a buddies griz, the 2 plugs on the throttle body can be interchanged, one fits a little to tight but they can be put on backwards.

 

[Cheapshot]

Three words, Throttle Position Sensor. Thats what the wires were mixed up on that Scoobie was talking about. I don't think the mixed up wires are your problem, but a fouled TPS is. I'm surprised thats not the direction your dealer sent you in straight away. Its on the side of the throttle body.

If your TPS is fouled, It'll run you in the neighborhood of $100 if my memory serves me correctly. You'll also need a set of security torx bits, avalible pretty much any hardware store for $10-20. The TPS is, how I understand it anyways, what decides how much fuel air it lets in per % of your throttle input. Your description leads me to believe that your TPS is fouled, because its sending an incorrect amount of fuel/air for the throttle position.

Check this link out, if you have to sign up, I would anyways, lots of great info avalible @ Grizzly Central.

Throttle Position Sensor Adjustment / Replacement Guide. - Yamaha Grizzly ATV Forum

It'll mention the whole tuning your TPS thing, it has to be between 20 and 100 or something. Its all in your pod anyways. There are instructions for that. You can go into that troubleshooting mod and figure out if your TPS is screwed or not.

If thats not it, I'm not sure what to tell you. The only other thing I've heard it could be is that one of the wires that plugs into the TPS has been pinched and is nfg.

If you really want, try giving PG Yamaha a call in Prince George, BC. They'll put a mechanic on the phone with you and they're really quite on the ball. Great to me in the past anyways.

 

[sergiomf]

Hi there
I have a 2007 grizzly 700 with exactly same problem.
Have you resolved the problem?
I appareciate

 

[whoDEANie]

Hi there
I have a 2007 grizzly 700 with exactly same problem.
Have you resolved the problem?
I appareciate

As Cheapshot mentioned, the easiest place to start is by checking your TPS. Below are some decent instructions I cut and pasted from TrackShare. Let us know how you make out.

You should be able to adjust through the digital display.Here are the spec's.

Fully closed throttle position 15-20 ohms.
Fully open throttle position 95-100 ohms.

Here is how you do it.Turn the main switch to off and set the engine stop switch to off.simultaneously press and hold the select and rest buttons,turn the main switch to on and continue to pressthe buttons for 8 seconds or more..Note -all display's on the
meter disappear and "diag" appears on the lcd meter.press the select or reset buttons for 2 more seconds to execute the selection.Select the diagnostic code # that applies to the item you want to check.When you press select it will move up in selection and when you press reset it will move down in selection.You want the display to read d01 for throttle position openings at closed and full throttle.When you apply the throttle watch the number's increase and decrease with throttle applied.If you see a glitch in the numbers or can not acheive the numbers i have told you replace the throttle position sensor assembly.I hope i have helped with your issue.Once you have completed this exercise just turn main swith off and it will go back to normal operation's on the gauge.