Renegade R4 Losing Power going uphill

[MJG]

I have an 08 Joyner Renegade R4.  This weekend we tried to climb a slightly steep hill but we kept losing power about 2/3 of the way up.   I am not sure if we simply don’t have enough power in the r4 or it was something else causing it.  
 

i would think it would have enough power to climb as a friend of mine has a Can Am 800 and made it easily, while we kept losing power. Any idea as to what this problem could be?  

[Dan B]

How slightly up hill is it?  Your 800cc engine in the R4 might not be enough engine if all the seats are occupied by adults..  That's probably why Joyner went to the 1100cc engine in 2014.  How is performance on level roads?  Check spark plug gap.  Check plug wires.  My car's plug wires were bad causing me to lose power going up hills.  High voltage was arcing to grounb causing misfires and losing power.