20 Alpha HC Soft On Top

[thump426er]

So, finally getting to where I almost have time to look at my sled before season fires up. But, last few rides out last season it seemed a bit soft on the top. Reved out fine, sounds fine, but just seemed a bit off on the upper end. Wondering what anyone would start looking at first to see if there’s an issue? PV’s out of adjust maybe? I don’t think reeds would impact just top end? I grabbed a different secondary spring to throw in before getting on it, and am secretly hoping maybe the spring is broken lol. Primary spring isn’t broken.

Dealer is backed up for a while right now and haven’t really done much on this sled myself as it just goes to dealer for warranty work as needed. Just curious what you guys would delve into first? Thanks for any thoughts.

 

[slyrydr]

revving out would seem to indicate engine is ok....soft on top would make me think clutching, changing to new belt, cleaning clutch faces as well as taking apart secondary, checking weights for binding, making sure both springs are ok....track tension....places where you might be losing engine power....compression check....piston rings, also piston scuffing due to water ingestion....probably something basic that just needs to be discovered before it makes more problems or a breakdown on the hill...

 

[Wheel House Motorsports]

Power valve spec check as well as clutching things as mentioned above.

Definately the difference between a sled that 'runs' and PULLS hard, 1HP here, 1 there, suddenly your not quite where another sled might be at for performance.

 

[thump426er]

Had swapped belts when I first suspected something was off, didn’t change. But didn’t think to do another compression test. When dealer threw that engine in under warranty I did a comp test before first ride so be good to see difference after some kms.

Thanks for the ideas and your time folks.

 

[bnorth]

Was there any revised mapping for the 20's that maybe got updated when it was in for the rebuild? When the dealer did a motor in my 19 they had to go to the new calibration and it is noticeably softer than the original 19 mapping.