I'm going to put a K&N with outwears and Boyseen pro series reeds on my 400. Should I get a clamp on filter or an OEM replacement? I assume I'll have to rejet. Where can I buy jets? Any suggestions on what size main to start with? Thanks!!!!

 

When I modified my air box(RCR Stage 1 kit), it came with a dual element filter, so that's what I've been using, but I go in heavy mud and water. I don't have an exposed filter. As far as the jets go, my scram came with a 230 main and I started with that in place and worked my way up to a 270 main before I got the right color on the plug. I's gonna depend on altitude and humidity may play a part also. We have real heavy humidity down here in southern louisiana and are also at sealevel. The 270 that I use is also in conjunction with air box mod, porting, pipe and silencer combo. So you may not have to go that high when jetting. The main jets are relatively inexpensive from the dealer if I remember correctly. Don't forget to stock up on plugs too. I've got a pretty good article on jetting I can send ya if ya think it might help. It's written in plain english that even I understood.

 

I have been there doen that, and I am much happier with what I have now. I have the HPD airbox with the Twin-Air filter that you also order with the kit. I have tried a slip on K&N, factory replacement UNI and I recommend the HPD mod. I love it, the box gives you much more room to access the carb on the go and it really flows alot.

 

NC..I'm not familiar with the HPD box. Think you could send me a pic of it? It would be nice to have better access to the carb.

 

I have some pics of the box in my pictures. Click the little camera under my name and icon to see them. You can also go to HPD's website to check it out. HPD Once you mount the box, you shouldn't have to remove it again unless you need to tear the bike way down or something, but in my opinion that is the best part. With the stock set-up you have to remove the airbox to access the carb and that takes alot of time and different tools. With the HPD box, just loosen the clamp on filter, slide it up and out of the box, then you can get to your carb very easily. It was the best investment I made to my scrammy, wish I had it along time ago. I cussed that factory airbox everytime I had to work on the carb.