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2006 yamaha 450 rhino has no top end 15 mph max

17K views 43 replies 7 participants last post by  sandbuster 
#1 ·
Hey kinda new to forum but I am having trouble with my 450 rhino. I can't get it to run over 15 mph. I have had carburetor cleaned,new air filter and new fuel pump. Welcome any suggestions as to what might be going on with its low top end. Has a strong take off. You can feel the back end squat on take off in high or low gears. Clutch sheaves and belt look to be ok. Was spitting and popping once gas pedal was mashed to floor but I changed out cdi and rhino quit spitting and popping at full throttle just no speed still.
 
#2 ·
Does it just go to that speed and stop and rpm is low? Or does it go to that speed and hit the rev limiter?

If low rpm, pull boot off carb, rev up and see if the slide moves up, if not the vacuum diaphragm might not be sealed good or have a hole in it

If hitting RPM then it is in the clutch, watch the belt travel as you rev it up, belt should run to nearly the top of the primary sheave


Todd
 
#3 ·
Todd the rhino slowly reaches 15 mph and just remains. I took the cover off the belt and belt is going all most to top of sheaves when I give it gas. Maybe a 1/8 of inch left at full throttle on sheaves. Belt does appear to be glazed but belt is intact. I will take boot off carb.and inspect the slide. Thanks for the response.
Bill
 
#4 ·
Is your reverse light flashing while going forward? Butt the rhino against something like a power pole and give it some gas in gear if it revs up then then like Todd said wet clutch may be wore out.
 
#5 ·
I don't see reverse light flashing at full throttle and I will try the clutch test when I go back to hunting club. I replaced stock cdi with aftermarket cdi and stopped the spitting and popping at full throttle. Don't think its clutch though because of torque it has on take off.
 
#6 ·
The original motor was replaced in August 2018 with another complete 450 motor from a jacked 2009 rhino. The guy had modified his rhino to pull 37's with the motor. He said motor would pull them at 40 mph. Not long after I installed new motor my fuel pump went out and I let rhino set from late November until late December. I have nothing but trouble with it since. I installed new vacuum pump which didn't seem to work. I then replaced vacuum pump with electric pump and finally got it to run . The electric pump solved the fuel pump problem but then was when i noticed it was not reaching the speed it had with other motor. It would start spitting and popping at full throttle of 15 mph. I thought maybe cdi was bad causing it to cut out so i replaced it with a aftermarket 660 cdi and stopped the spitting and popping but still no speed. That is where I am at with it now.
 
#8 · (Edited)
Wet clutch is good......I don't think you can make a 660 CDI work in a 450
 
#9 ·
Since I have limited belt and clutch from scenario, I am thinking of putting a dyno jet kit in carburetor in hopes of increasing power. The cdi I have in rhino is labelled for 660 and grizzly but will work in the 450. Only difference is brake pedal has to be mashed in order for it to crank. It also added a little power and increases rev limiter.
 
#17 ·
The stock fuel pump is a low pressure 1-2 lbs, that's why it takes so long to pump gas up to the fuel pump once it looses prime marine bulb fixes that.
 
#28 ·
Here is what you said earlier

Todd the rhino slowly reaches 15 mph and just remains. I took the cover off the belt and belt is going all most to top of sheaves when I give it gas. Maybe a 1/8 of inch left at full throttle on sheaves. Belt does appear to be glazed but belt is intact. I will take boot off carb.and inspect the slide. Thanks for the response.


Now you say it is cutting out, two totally different things

Also you said the slide was not going to the top and I said the diaphragm might be the issue but you said you bought a slide.

So is the slide going to the top now?

Are you hitting a rev limiter or not at 15 mph?

Did you replace or look at the diaphragm?
 
#29 ·
Sorry Todd if things are sounding confusing at this point. I did replace old carburetor with a new slide and diaphragm . I also replaced fuel pump with genuine Yamaha stock pump and also reinstalled stock cdi. Yes with the stock cdi, stock fuel pump,and new diaphragm and slide the 450 rhino would only reach 15 mph and this time it did appear to be cutting out at 15 mph.
So I went bought a new stock carburetor and belt this morning and installed them with very little change. I did actually gain a whole 2 mph. It will now get up to 17 mph before it would start acting like it was cutting out. I did reinstall the 660 cdi and it appears with that cdi it doesn't try to cut out as much at 17 mph as with stock 450 cdi. So at this point after accumulating 550$ in new parts I am only 2 mph better off. So i am clueless at this point what is wrong with it.
 
#30 ·
Unless it is an aftermarket 660 CDI the 450 CDI revs higher so you would lose speed. Then if a aftermarket one, the difference in a 660 aftermarket and a 450 stock one is not very much unless you buy a Dynatek one and best to buy a Dynatek 450 CDI

So lets focus on the cutting out part, does that mean you are hitting the Rev limiter?
 
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