Yamaha Rhino Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
255 Posts
Discussion Starter #1
I have a 2007 660 Rhino. I put an aftermarket billet exhaust tip on the exhaust. The only difference between stock and the billet tip is increase from approx. 1” to 1.5” opening, and the billet tip is straight.

Ever since changing the exhaust tip, the Rhino backfires when I let off the gas.

The motor and carburetion is bone stock. I have a BRP CDI but I had that with no issue before the tip change.

Can anyone provide info on what the issue might be?

Thanks a million!!!

Rob
 

·
Premium Member
Joined
·
3,006 Posts
I have a 2007 660 Rhino. I put an aftermarket billet exhaust tip on the exhaust. The only difference between stock and the billet tip is increase from approx. 1” to 1.5” opening, and the billet tip is straight.

Ever since changing the exhaust tip, the Rhino backfires when I let off the gas.

The motor and carburetion is bone stock. I have a BRP CDI but I had that with no issue before the tip change.

Can anyone provide info on what the issue might be?

Thanks a million!!!

Rob
I believe the exhaust tip requires rejetting .....
 

·
Life serves the risk taker
Joined
·
4,198 Posts
tweeking your a/f is the solution I believe. It helped me and I've read it several sites that talk about jetting.
 

·
Registered
Joined
·
798 Posts
mine backfired for the first time yesterday and i didnt change a thing.
 

·
Premium Member
Joined
·
3,006 Posts
I know nothing about jetting only what I have read .... so I agreee with Chandler...
 

·
Registered
Joined
·
1,959 Posts
Fuel filter might be dirty?
 

·
Premium Member
Joined
·
3,006 Posts
mine backfired for the first time yesterday and i didnt change a thing.
That could be from running a low octane fuel .... Mine backfires with anything less than 91 octane ....

Also if you run it at high speed for an extended period of time and then let off of the throttle it may backfire ....
 

·
Registered
Joined
·
2,500 Posts
Adjust your fuel mixture screw slightly richer and it should cure your problem. Mike, if you backfire with anything less then 91 octane you should probably do the same thing. 91 octane resist the backfire more than 87.
 

·
Registered
Joined
·
255 Posts
Discussion Starter #10
Where is the fuel screw and how do I get to it?

Which way do I turn it?

How many turns?

Thanks for everyone's help!

Rob
 

·
Life serves the risk taker
Joined
·
4,198 Posts
The fuel mixture screw. I called it the A/F screw in this picture. 2 turns out is normally good.

You need to put a small drill into the brass plug and either insert a screw and pull it out. Mine came out while I was drilling it.

Turn the screw in until bottomed and then 2 turns out.

 

·
Registered
Joined
·
255 Posts
Discussion Starter #12
Chandler:

Wow...thanks a million for taking the time to post the photo and instructions for me! Please help me with the following if you don't mind!

It looks like I have to remove the carb to gain access to the A/F screw?

I thought 2 turns out was the way it is set up at the factory?

Turning it out makes it richer or leaner?

I ride my Rhino (BRP CDI) in Rocky Point. What jets should I have in it or are the stockers okay?

What jet is located to the right of the main jet in your photo?

Should I put a breather filter on the trans vent while I am at it? Where is it located and where do I get one?

Thanks again!

Rob
 

·
Site Founder
Joined
·
7,903 Posts

·
Life serves the risk taker
Joined
·
4,198 Posts
Chandler:

Wow...thanks a million for taking the time to post the photo and instructions for me! Please help me with the following if you don't mind!

It looks like I have to remove the carb to gain access to the A/F screw?
Yes and flip it upside down. I loosen both end clamps of the carb and the clamp for the boot connecting to the airbox. I can twist mine around without removing anything except the big vacuum line that plugs for the needle jet diaghram.

I thought 2 turns out was the way it is set up at the factory?
Don't know. Mine did the same and when I adjusted, it was screwed all the way in.

Turning it out makes it richer or leaner?
Richer

I ride my Rhino (BRP CDI) in Rocky Point. What jets should I have in it or are the stockers okay?
Same as Phoenix. You shouldn't be much different just with the tip but before you remove the carb, do a high speed run, full throttle and immediately shut it down and check the plug. The CDI also let's it rev higher which may require a richer main.

What jet is located to the right of the main jet in your photo?
I think it's called the power jet but no one ever does anything with it.

Should I put a breather filter on the trans vent while I am at it? Where is it located and where do I get one?
I think your talking about the CVT filter and yes, it's a good idea. The outlet is right behind the driver seat. Check rhinocrap.com and see if they carry them or call them.



Make sure you don't drill too deep when removing the plug. You just want to get a screw in for a handle to remove the plug.
 

·
Registered
Joined
·
184 Posts
Dumb question, but when you guys say to adjust the air fuel mixture screw out 2 turns, what is considered a turn? Is it done in 1/4, 1/2 or a full turn to equal 1 turn.

I was having stalling issues with my rhino like it was running out of gas. I switched to a high flow fuel pump, I swapped the needle washers to get it to run richer, and put on a tri fire cdi. Now I am getting loud back fires if I run it full throttle and let off the gas.

Thinking the air/fuel screw is my next adjustment. Am I going the wrong direction in trying to fix it, or is that sound like it could help?
 

·
Registered
Joined
·
2 Posts
hey guys i need help, i have an 07,660. i just replace the carb with a factory one. it runs great at idle but when you give it gas it bogs out and backfires, i have adjusted the a/f screw a little in both directions but very little change. i can put my hand over the airbox and restrict the air flow by at least half and it run great, ANY IDEAS
 

·
Registered
Joined
·
22 Posts
Probable causes; Exhaust leak at manifold (check nuts), air screw needs to be turned out a bit (bottom side of carb), Larger pilot and/or main jet, Jets need to be cleaned...thoroughly!
I recently purchased an 05 Rhino with dual Dasa exhaust. With only 30 hours the car has limited use and I could tell maintenance was a bit remiss. It backfired terribly at decel. I cleaned the jets with those little jet brushes, found a piece of fine wire that would go through the jet completely, general carb clean, etc. I then turned the air screw mixture out 1/2 turn (turn the screw all the way in...gently until is seats then 2 FULL turns out.
Cured the backfire at decel.
Good luck.
 

·
Registered
Joined
·
2 Posts
Well after fighting with a backfire problem four years I installed a Electric fuel pump new CDI rebuilt the carb Well let’s ask ourselves what causes a backfire a lean fuel condition and loss of power no one ever looks at the fuel line Well I put a clear 1/4 inch line between the fuel pump and the tank and low and behold an Air Bubble that just keep growing The fitting on top of tank is plastic and leaks air into your fuel line causing a air bubble that has to hit you’re fuel pump causing a lean situation The fix replace the plastic fitting on the top tank keep your old one take to a machinist to make out metal at lest that’s what I am going to try
 

·
Registered
Joined
·
2 Posts
Well guys no one has thought of this If your drawing air into your fuel line from your tank to the fuel pump (leaking plastic fitting) causing a lean condition and backfire after a new cdi rebuilt carb electric fuel pump I found the problem bye putting it a clear fuel line in between tank and fuel pump low and behold I watched the bubble grow to ten inches the fuel pump does not like pumping air this causes a lean condition. The fix replace plastic fitting I Am going to make my own out of metal my backfire is fixed
 
1 - 20 of 20 Posts
Top