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Discussion Starter #1
Im working on an 06 450 rhino, it is a job and not my own. It is all stock. The valves were just adjusted. The air filter is clean and oiled. The gas smells good but i dont know the age. Before i adjusted the valves i started it up when he dropped it off. It fired right up with the choke. I then turned it off so the engine wasnt hot for the valve adjust. After the adjust, i tried to start it and had an exremely hard time starting it. I finally got it started and it idled for several minutes then the idle fluctuated and stallled. Once it stalls, i sometimes start it easily and sometimes its hard. Also after stalling its idle fluctuates and stalls typically within 30 seconds. I played with the fuel screw and it seemed to get better almost all the way out. The throttle response is good. I installed a 22.5 pilot from the stock 20 pilot and checked all the passages while at it. The carb is perfect. It still does the same thing. I can play with the air box flow and it seems to get better with less air. If i pull the choke slightly it sounds great. I installed a clear hose on the fuel line and the gas flow looks good. I am doing all this with the gas cap removed to bypass vaccum lock. I dont hear too much difference when playing with the fuel screw. I dont see any reason why it should be running lean while stock and with a larger pilot. No air leaks in the intake also. Please give any advise as to why the rhino could be stalling. The compression is good and i am going to try a new spark plug tomorrow. Thanks in advance!
 

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I know you said that you said you checked all the passages, but you might want to clean all the passages in the carb also. There seems to be something clogged since it runs better with a little choke.
 

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something in the carb is still pluged or intake leak or valve too tight....
 

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I would recheck the valve clearance first. Then move to the spark plug and see what the color is. It should be about the same color as cardboard not black nor white. I have seen the choke stick in the carb and did not know it by the feel of the choke lever and cause some what the same problem. Make sure the battery is fully charged just because. Please let us know your findings so we all can be that much smarter.
 

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aren't you supposed to set the valves with the engine warm???? not cold
No, cold
X2


COLD – COLD – COLD

ADJUSTING THE VALVE CLEARANCE
• The valve clearance must be adjusted when the engine is cool to the touch.
• Adjust the valve clearance when the piston is at the Top Dead Center (TDC) on the compression stroke.

1. Remove:
• driver seat
• passenger seat
• console

2. Lift the cargo bed up.

3. Remove:
• tappet cover (intake)
• tappet covers (exhaust)

4. Disconnect:
• spark plug cap

5. Remove:
• spark plug

6. Remove:
• air shroud 1

7. Remove:
• engine cooling fan 1

8. Remove:
• timing plug 1

9. Check:
• valve clearance

IF Out of specification →Adjust.



TDC
Turn the crankshaft counterclockwise with a wrench.
Align the “I” mark on the rotor with the stationary pointer on the A.C. magneto cover. When the “I” mark is aligned with the stationary pointer, the piston is at the Top Dead Center (TDC).

• When the piston is at the Top Dead Center (TDC) on the compression stroke, there should be clearance between the valve stem tips and their respective rocker arm adjusting screws.

• If there is no clearance, rotate the crankshaft counterclockwise one turn.
Measure the valve clearance using a thickness gauge



10.Adjust:
• valve clearance

a. Loosen the locknut 1
b. Insert a thickness gauge between the adjuster end and the valve end.
c. Turn the adjuster clockwise or counterclockwise with the tappet adjusting tool until the proper clearance is obtained.
d. Hold the adjuster to prevent it from moving and then tighten the locknut.
e. Measure the valve clearance.
f. If the clearance is incorrect, repeat the above steps until the proper clearance is obtained.


11.Install all removed parts
• engine cooling fan
• air shroud
• spark plug
• tappet covers (exhaust)
• tappet cover (intake)
• console
• passenger seat
• driver seat
 

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Discussion Starter #11
Alright guys, i figured it out. it was the spark plug. thanks for all the input. i double checked my valves just to see, but they were good. thanks for all the advise.
 

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Dont forget the little plastic plug behind the fan. (like I did)
 
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