Keeway RKV 125 (K157FMI) Tuning

[Dviine]

Hi all, first post here.

The title pretty much says it all. I'm looking to gain a little performance from my RKV 125. It uses a KW157FMI-2B engine but that's about all I know.

Here's a picture for reference
12931242_10209254251579728_2495398946394954096_n.jpg

I want to start by replacing the massive airbox with a K&N style filter and re-jetting the carb. I have started saving for an Arrow full stainless steel exhaust system.

I was thinking this filter as it has a cover to keep rain out and I believe 42mm is the correct size for the carb?

http://www.ebay.co.uk/itm/191837877710

Then what to do about the crank case breather tube and SAI tube? Are there smaller filters you can buy or should I just use some old cloth and ziptie that in place of a filter on these 2 tubes?

I'm not sure what size main jet to go for either. I was thinking 105 but I'm new to messing with engines so not sure on this size. Should I also change the pilot jet size and what will be the benefit of this? If I do change the pilot jet, what size, 40?

Will this main jet fit my carb?

http://www.ebay.co.uk/itm/271325913913?var=570217069007

I'm open to changing sprocket size also, however I don't know which way to go. I would like to have more useable power, but I also regularly top my bike out and would like a bit more top end.

Finally, what sort of performance will I be looking at after the re-jet, filter and de-cat exhaust? I top out around 65mph now, would like to get to 70mph without too much hassle.

If I'm wrong on anything, please correct me. If you want to recommend products in place of what I've posted, please link them and I'll take a look:)

Thanks guys, sorry for the long post.