99 Polaris Sportsman 500

Very low acceleration power, in neutral it will rev up but its slow to get there (no popping or backfiring)
Going down the road its slow to pick up speed and it will never fully rev up

Anyone else had a similar dealing with this?

Update: Found pin holes in carb slide diaphragm

 

I'd check the clutches and belt for wear especially the rear clutch rollers. Could be all that is needed is a new belt and blow out belt dust "IF" belt has more than 1 1/2" slack from a straight edge when it's placed across both clutches and the belt is pulled down at the center. Or has any glazed spots along the edge also.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse Still wouldn't rule out a cam exhaust lobe problem as loss of power is the first sign and popping back and will idle only comes when the lobe is completely worn down.

 

Could be as simple as the throttle cable or worn out belt. Or it needs a carb clean, and it could also be the Sensor switch in the gear selector that is malfunctioning.
Hope it helps

 

Symptoms are the same in neutral or in gear with the exception of in gear it doesn't rev out as fast due to the fact there is a load on the engine. I would think its safe to say belt is not probable (neutral or driving) - its not like its revving up super quick but the machine isn't moving - it moves in tune with the engine rpm just slowly
The exhaust cam lobe is another one I thought of.
Btw appreciate the input

Except since I found pin holes in the carb diaphragm I am going to replace then see how it performs.

 

Clutch buttons can cause that also. Here is a person with your problem.
What clutch related parts wear out and cause loss of acceleration? - Polaris ATV Forum

 

Found the problem. Tiny pin hole in the carb slide diaphragm. Replaced and fixed for those who may see this post later on with this issue. Thanks