[Suddy]

Hi, just bought a 2017/18 Yamaha grizzly 700. 200 hours, when the quad is stationary if you blip the throttle the quad stalls, gets you if you set off from lights etc, if you feather the throttle it runs all day, also after riding the quad will cut out after about 10 seconds, I don’t know if this is related, it’s had new fuel pump, spark plug etc, the throttle position sensor looks like it’s been off, is there a way of testing these with a multimeter?
Any info would be brilliant

 

[RedRocket]

Welcome to the forum.

There is a section in the Yamaha Service Manual for testing the TPS. Forum vendor 501parts.com hosts the Service Manuals to where you can use them, via this link - Troubleshooting - 501 Parts.com Yamaha 4wd System Parts and Repair . Scroll to the bottom and find the appropriate manual.

You should also consider adjusting your valves if you haven't done that.

 

[Suddy]

Welcome to the forum.

There is a section in the Yamaha Service Manual for testing the TPS. Forum vendor 501parts.com hosts the Service Manuals to where you can use them, via this link - Troubleshooting - 501 Parts.com Yamaha 4wd System Parts and Repair . Scroll to the bottom and find the appropriate manual.

You should also consider adjusting your valves if you haven't done that.

Thanks for the reply, I have tested the TPS and it’s in spec but looks like you need to plug it in to fit it

 

[Ridgway81432]

Welcome from Colorado.
I would adjust the valves (check and adjust if needed). What did the old plug look like?
Does it go into gear easy, not jump with a smooth idle?
I may have sour gas in the tank, its had less than a 1/2 a tank a year run through'er'.
I would add injector cleaner to a partial tank and giver it a rip to blow out the cobbs.
If you add injector cleaner, do it on a low tank in the correct ratio, what you can run out in one day. Then add more gas at the days end to dilute the cleaner, some can be hard on rubber seals and hoses if left to sit.

 

[Suddy]

Welcome from Colorado.
I would adjust the valves (check and adjust if needed). What did the old plug look like?
Does it go into gear easy, not jump with a smooth idle?
I may have sour gas in the tank, its had less than a 1/2 a tank a year run through'er'.
I would add injector cleaner to a partial tank and giver it a rip to blow out the cobbs.
If you add injector cleaner, do it on a low tank in the correct ratio, what you can run out in one day. Then add it more gas at the days end to dilute the cleaner, some can be hard on rubber seals and hoses if left to sit.

 

[Suddy]

I’ve got a video of what it’s doing but can’t find a way to upload it on to here

 

[CanadianKodiak700]

I’ve got a video of what it’s doing but can’t find a way to upload it on to here

Upload to youtube, then post the link

Sent from my Pixel 5 using Tapatalk

 

[reogem]

Thanks for the reply, I have tested the TPS and it’s in spec but looks like you need to plug it in to fit it

I'm just addressing the TPS since you indicated that someone may have tampered with it.
You have confirmed the TPS OHMs between 3.08 and 5.72 Ω.
Next you need to adjust it to the proper voltage between .63-.73 volts. Note the voltage with the throttle closed. To help with stalling adjust the voltage up a few hundreds if you test at .65 move it up to .67-.69. If this doesn't help the stall the issue it is somewhere else.

 

[reogem]

Considering you have a new fuel pump. It would be a good idea to confirm that it is installed correctly and has correct pressure.

 

[Suddy]

Welcome from Colorado.
I would adjust the valves (check and adjust if needed). What did the old plug look like?
Does it go into gear easy, not jump with a smooth idle?
I may have sour gas in the tank, its had less than a 1/2 a tank a year run through'er'.
I would add injector cleaner to a partial tank and giver it a rip to blow out the cobbs.
If you add injector cleaner, do it on a low tank in the correct ratio, what you can run out in one day. Then add more gas at the days end to dilute the cleaner, some can be hard on rubber seals and hoses if left to sit.

Plug looks fine mate gunna have to get some one to check the valves as think you need a tool

 

[Suddy]

Plug looks fine mate gunna have to get some one to check the valves as think you need a tool

This is what it’s doing

 

[reogem]

Kinda sound like a fuel delivery issue. Like pressure issue, broken or clogged pickup,

 

[KodiakAfishyo]

Could be a dirty or defective injector

 

[Suddy]

Kinda sound like a fuel delivery issue. Like pressure issue, broken or clogged pickup,

It’s really annoying me now because no codes on I can’t just replace everything the parts are really expensive, one sensor on throttle body alone is £300

 

[KodiakAfishyo]

Take the injector out and clean it...that doesn’t cost anything.

 

[Suddy]

Take the injector out and clean it...that doesn’t cost anything.

That’s first thing I’m going to do this morning

 

[Suddy]

Take the injector out and clean it...that doesn’t cost anything.

Done still no change

 

[reogem]

It’s really annoying me now because no codes on I can’t just replace everything the parts are really expensive, one sensor on throttle body alone is £300

As you have a new fuel pump it may have a broken or clogged pickup/filter or possible a bad pressure regulator. You would need to remove the fuel pump to inspect.
Here is a vid explaining. It is aimed at motorcycles but should help you.
Yamaha EFI

 

[Suddy]

As you have a new fuel pump it may have a broken or clogged pickup/filter or possible a bad pressure regulator. You would need to remove the fuel pump to inspect.
Here is a vid explaining. It is aimed at motorcycles but should help you.
Yamaha EFI

The full pump assembly has been swapped from another bike, it’s really strange nothing worse having problem like this. I’m trying to book it in at a dealers but there all busy for weeks 😌

 

[reogem]

Good luck!