Jump to content

Beta rev 4-t 300 sometimes running unstable


rollo
 Share

Recommended Posts

Hi all,

I have a rev 4-t 2008 racing.

Most of the time it runs fine.

But after some time it starts to runs unstable stationary (misfires?).

Also sometimes the engine stops in the middle of a nonstop. After a kick it runs fine.

Does any of the above sounds familair to anybody?

Or maybe someone got any advise?

Thanks in advance.

Edited by Rollo
Link to comment
Share on other sites

 

 
 

Hi all,

I have a rev 4-t 2008 racing.

Most of the time it runs fine.

But after some time it starts to runs unstable stationary (misfires?).

Also sometimes the engine stops in the middle of a nonstop. After a kick it runs fine.

Does any of the above sounds familair to anybody?

Or maybe someone got any advise?

Thanks in advance.

Mine was exactly the same. The bikes come with jetting that is way too lean, and causes this problem. The carb is the same as that used on the Yamaha Raptor, so you can get parts from the Yamaha shop.

You want to start here:

Pilot jet: 22.5

Main jet: 130 to 135

Air screw: 2 3/8 turns out

Needle clip: 2nd slot down from the top (thick washer below clip and thin washer above)

Once done, it was a totally different bike and ran smooth as silk, with perfect idle.

Link to comment
Share on other sites

 
 
  • 5 months later...

Mine was exactly the same. The bikes come with jetting that is way too lean, and causes this problem. The carb is the same as that used on the Yamaha Raptor, so you can get parts from the Yamaha shop.

You want to start here:

Pilot jet: 22.5

Main jet: 130 to 135

Air screw: 2 3/8 turns out

Needle clip: 2nd slot down from the top (thick washer below clip and thin washer above)

Once done, it was a totally different bike and ran smooth as silk, with perfect idle.

@DGShannon

I've cleaned my carb and made a picture of the needle, is this the setting you mentioned?

I've changed the clip to the position marked with the arrow.

In my opinion this way the needle gets more lifted, so a richer mixture gets in the engine.

image_url-10868-1326650029.jpg

Link to comment
Share on other sites

 
 
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...