Yamaha Engine breaking up at 25 mph

asutoad

New Member
Aug 1, 2012
6
0
0
I am having an issue with the engine breaking up at 25 mph. I have gone through the carb and changed the coil. With a stock cdi I get 25 mph and with an aftermarket cdi I get 31 mph. What do you suggest I do next. The thing fires up great it is almost like it is hitting the rev limiter. The belt seems fine also. It is very consestant so it make me feel like it is electrical. Thanks for any help or ideas. It is a 2007 660 rhino.

Dave
 

poflo

New Member
Jan 3, 2011
138
0
0
Put a new plug in it....easy check;).....Gravity feed fuel may not open the needle on high demand...it works on start-up & idle,but not if the bowl is full due to spring on needle( needs 3 to 4 psi)
 

Glamisfan

Active Member
Oct 26, 2009
671
103
43
imperial valley
If it revves to 8000, then probably one of the rollers in the primary cvt clutch fell sideways. Time for a cvt rebuild. And if you've never put in a modified primary, then now is the time to do it. I'd suggest the Hunterworks greaseless wedge one's.
 

c&c rhino

UTVUnderground SXS Tech - UTVUnderground Approved
Jan 18, 2009
351
11
18
lake elsinore, ca
if it revs up to 7k ish then its probably a roller weight issue in the primary clutch. if its breaking up under say 4k there could be a few things. make sure your plug cap is good, there is a wire that snaps onto the plug inside the cap that can break, especially if the rubber plug isnt correctly seated in the valve cover. if thats broken and the rubber plug isnt keeping it in place it can bounce around causing misfires. a stuck reverse limiter switch usually causes it to hit the rev limiter pretty low in the rpm range but its a possibility. gravity fed fuel will still fill the float bowl and it has a regular float with needle and seat so that should be fine for testing. you already tried the stock cdi so that should take it off the list.
are you sure the cable is pulling the butterfly all the way open in the carb? ill try and think of other possibilities.
 

Members online

Forum statistics

Threads
17,292
Messages
179,387
Members
12,145
Latest member
felipebenjamin000