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New here, grizzly has no power

232 Views 5 Replies 4 Participants Last post by  Ridgway81432
I have a 2014 yamaha grizzly 450, carbeurated automatic that won't exceed 20 mph and has no power getting to that speed either.

Always used non-ethanol fuel and seafoam, took the carb apart and everything looked as good as new. I went ahead and replaced the fuel pump diaphram, spark plug, cleaned the air filter and now I don't know where to turn. Any input on what might be the cause?

I appreciate any feedback and look forward to being apart of the forum.
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Welcome from Colorado.
I suggest a full tune-up including valve lash check and adjustment if needed.
Have you done a compression test?
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Another question for @Southern yakker

Does your Grizzly 450's engine sound healthy/normal and that the power is just not getting to the wheels?
I haven't done a compression check, the engine sounds healthy and was running just fine the week previous to the issue. When driving the Its not getting the RPMs up so started with thinking its a fuel issue but now I'm leaning toward electrical
Yamaha valves are known to stretch slightly, generally in the 1st 1000 miles, this changes the valve lash so the valves do not close fully so the compression is lower causing the m.p.g. to go down and the power produced to go down.
To adjust the valve lash the timing is confirmed to be dead on, so with the engine properly timed, good spark and proper a/f ratio she'll go.
I suggested checking the lash as its a no charge adjustment if you can do the work your self.
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