I doubt it affected top speed very much, but it was definitely an improvement in power. The bike revs more freely and the throttle response is better with the Q4. Top speed would be more a factor of final gearing, but the Q4 would definitely help you reach top speed a little quicker.
We did notice that if we chop the throttle from wide open to nothing, it will backfire. Other than that, it runs great. As far as being lean, I plan on pulling the plug and diagnosing it. I'll post some video when I do, so stay tuned!
@LagBros_3 I had a 2021 klx300r. At the time, no aftermarket exhaust was available, c0vid era. So, I had to make a complete system for my bike. I first tried removing the stock baffle like you did. But it didn't do much. The pipe I made made a big difference, though. But what really helps that bike us the Dobeck fuel tuner and opening up the airbox. I think I did the pare valve delete kit as well. Also, replacing the o-ring chain with a high quality non o-ring frees up some power. Those bikes are a lot better than they get credit for. The mods I did made it even that much better. It is tall, though. But it's hard to beat for tight trails. Especially for the price.
@Gigachadly If I remember correctly, right under the seat, you'll see a snorkel and cover. They both should pull out. We work on a lot of bikes, so it's hard to remember exactly. If I'm wrong, yes, you can drill 4 or 5 one inch holes in the top of the airbox. But I would recommend getting the fuel tuner before you do it. Letting that much air in without adding more fuel will lean out the mixture and cause it to run hot. If you are interested in a full system for one of your bikes, let me know. I took the system that I made off before I sold the bike. It's trail ready with a built-in spark arrestor.
That must have been quite a bit of work to build a full system! Sounds like a cool project. I agree, these bikes don't get enough credit at their price point. And yes, there is a snorkel that can be removed, and I'll have to do some research on the pare valve delete. Before I do any of that, I am going to get a tuner as you mentioned. In my opinion, these bikes already seem to run hot so I don't want to make that any worse.
