Power difference suggestions

[darebee]

I have an 87 Warrior. Bike is a little tough and I have been shopping for parts. So today I find an 89 for sale cheap and it looks really nice so I pick it up figuring to jockey the 87.
I get the 89 out for a rip and it has NO TOP END at all. The 87 royally kicks it's ass. The 89 has superb bottom end but it just tapers off in the middle and flat lines (kinda like a big diesel does).
I am thinking it may just be the Carb but am looking for any opinions you wish to offer.
Who knows what or if any engine work has been done to either of these machines.
I may swap the carbs next week to see what that does.
I am kinda disappointed.
TIA

 

[01warriorguy]

I'm no expert, but maybe you have a different size sprocket on the 89? therefore taking away from your top end and adding extra bottom end

 

[darebee]

They are both 13's.
It has nothing to do with speed. The engine simply won't rev out.
I am starting to have a sneaky suspicion that there might be some cam/valve/bearing issues.