Originally Posted by Aprilia
There is no extra torque or extra hp with this upgrade lol. Its simply replacing an OEM item that has a long history of failure. Your 89 also has multi piece balancer sprockets that should be replaced by 20K miles. Kawi upgraded those in 96 but any late model sprockets will work. I can send you all the OEM part numbers if you need them. Hope that helps!
If you could please send me those OEM numbers that would be great. Thanks