2017 Polaris 450 missing decompressor ball

[huanchaco]

Bought a 2nd hand 2017 polaris sportsman 450  with 12000 hours recently and have done a lot of maintenance including a new 18 amp battery

to assist faster starting. Having expected to find a 4 valve head i took the valve cover off and found a single ohc with its 2 buckets. At first dissapointed, i realized

this was a run forever engine, no visible wear noticeable and still running perfectly. The decompressor ball was missing in the camshaft, with the lever and spring

still in place. Since the motor starts at once every time i think its better to keep the camshaft as is . In my experience a decompressor is only needed for a manual starter.

[mxracer13]

I just had the same sort of issue with my 2017 450 HO and it lead to my cam breaking. The ball had fallen out of the hole and was rolling around on the head. I only have around 400 miles on mine. If I could I would get a cam without it.

 

[huanchaco]

59 minutes ago, mxracer13 said:

Shouldn't be a problem MX, Take the cam out,and enlarge the hole with a mini grinder so the ball comes out. The actuator can remain in place or remove the sprocket and get rid of it. A full size (18 amp ) battery can handle the compression easily. In my 50 years as a mechanic i've never seen such a brilliant cam lobe destroying device as in Polaris. Go for it

 

I just had the same sort of issue with my 2017 450 HO and it lead to my cam breaking. The ball had fallen out of the hole and was rolling around on the head. I only have around 400 miles on mine. If I could I would get a cam without it.

 

On 6/22/2021 at 8:09 AM, huanchaco said:

Bought a 2nd hand 2017 polaris sportsman 450  with 12000 hours recently and have done a lot of maintenance including a new 18 amp battery

to assist faster starting. Having expected to find a 4 valve head i took the valve cover off and found a single ohc with its 2 buckets. At first dissapointed, i realized

this was a run forever engine, no visible wear noticeable and still running perfectly. The decompressor ball was missing in the camshaft, with the lever and spring

still in place. Since the motor starts at once every time i think its better to keep the camshaft as is . In my experience a decompressor is only needed for a manual starter.

 

[huanchaco]

Almost forgot MX, a full size battery might rub against the prop  shaft, I had to loosen the bolts of the battery case and move it a bit outwards .