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Discussion Starter · #1 ·
New to site and need help. I’ve searched thru other posts and have not found exact problem. I have an 03 660 that has had some backfire issues and seemed to be running a little rich. I pulled carb bowl and cleaned the best I could although it look spotless. Put back together. I also adjusted fuel air screw. Put all the way in and backed out to 2 1/2. Quad starts and idles good but I’ve lost power and top end speed. Only gets up to about 30 mph. Need suggestions on what to look for that would cause this issue. I have not messed with anything else.
 

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Hey...Phillip81..Welcoem to GC from Wisconsin.

I would check at the simple stuff first. Is the throttle cable assembled correctly? Does it open the throttle valve completely?
Is the float height correct?
 

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Discussion Starter · #3 ·
Cable I turned until idled up antlers then backed off slightly and locked down. Looks like valve opens completely when I hit throttle. Not sure about float. I didn’t know that could be adjusted. I just put it back on the way it was originally
 

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This is a little different then the issue I had on my '02 but you can try cleaning out the needle and seat. Mine would cut out and backfire but not the loss in top speed. I had to get a new needle and seat but now it runs like a champ. Worth a try. Before you buy a new one make sure that this one is bad. If it is getting stuck then clean it up. If that doesn't work go spend the $20 on a new needle and seat. Also I assume this just happened and it's not the speed screw limiting the speed. I hope you can figure it out!
 

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Discussion Starter · #5 ·
All I had was frequent backfire and occasional would cut out. I figured i would clean carb and adjust fuel ratio as I knew I was running a little rich. I went from unit running descent to worse with that attempt. I was searching for a rebuild kit and found a whole new carb for under $60. Rebuild kit was around $30. For the difference I just ordered a new carb. I’ll install that in a few days when I get it and hopefully my issues are gone.
 

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I would say that's a good call. I wish I would've just ordered a new carb. I ended up replacing an O-ring on the choke, adding a new bowl gasket, and a new needle and seat. By that time I had dropped about $40 in my carb and I still had all the old jets. If I could do it again I would get a large jet kit and a UNI and have the extra power. I hope the carb is the fix. Let us know what happens!
 

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Discussion Starter · #7 ·
Replaced carb and adjusted intake valves. Runs like a top now. Not really sure where my issue was. Going to tear down old carb to see if I find issue. Either way this is the best quad has sounded since I got it. Thanks for your input.
 
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