[Puddleduck62]

I put on a aftermarket carb and didn’t adjust anything normally they work fine. This one upon start will idle for s second then rev up really high for a few seconds then back to idle and keeps repeating. Also the speedometer got some water in it and needs replacing would this make it cause that problem? TIA David

 

[SamUK]

What ATV is it?

The main issue is the aftermarket carb, scrap it and buy a used known good OEM replacement and overhaul with an OEM or known good brand service kit such as shindy.

 

[Puddleduck62]

What ATV is it?

The main issue is the aftermarket carb, scrap it and buy a used known good OEM replacement and overhaul with an OEM or known good brand service kit such as shindy.

It’s a 2007 Rancher

 

[billy5221]

Are you sure it's a 07? Thats the year they started putting fuel injection in the rancher and made it a 420, or did you put a new throttle body on it?

 

[Puddleduck62]

Are you sure it's a 07? Thats the year they started putting fuel injection in the rancher and made it a 420, or did you put a new throttle body on it?

They said it was a 07 and this is what it looks like.

 

[SamUK]

They said it was a 07 and this is what it looks like. View attachment 149152

I'd start again with an OEM carb, those China cheapies never work. Search the forum, you'll see so many posts about them, they ALWAYS cause issues.

 

[billy5221]

That's right I forgot they still offered the 400 rancher in 07, like said above it could be the China carb, try rebuilding the old one or find a used OEM or they still sell new OEM carbs on partszilla, and rockymountainatv for around 160

 

[LedFTed]

learn how to rebuild one. and use a shindy kit. you will never regret it..
dont buy from china the best you can

 

[TRXStudent]

I think the constant revving means its 'hunting'. Could mean your idle jet is plugged.