If anyone can tell me what they think about my future mods i would appreciate it. Please let me know what you think about them and what kind of difference that i should be able to tell.

11:1 wiesco piston, bored out to be a 416, ported and polished, xr400 cam, cdi rev box, k&n power kit, jetted up, no lid. I also already have a full exhuast system from LRD.

 

Whats your total cost on these mods and how much better does it run? also what gearing do you run?
Just some? thinking about close to the same for mine is lowend improved? its a must for me I ride alot of trails and very rarely ever get out of third.

 

If you are wanting more low end power the best thing possible for you to do is drop down to a 14 tooth front sprocket. If it's not enough go to like an 39 or 40 back sprocket. I partically like the thought of the k&n filter and jetting the carb. Filter runs abouts 35 dollars, and jets are like a dollar each. I would probably put 6 one inch holes in your air box lid. Try the sprocket, k&n, and do your own holes. Those mods would keep you around $75 to $85 dollars. You will tell a huge difference. If it's not enough go to a higher compression piston. That would add about 150 more dollars.

 

A JE piston may be a better selection. From what I've heard, they tend to hold up quite a bit better and aren't quite as sensitive to to heat fluctuations. I know they have a 10.5:1 compression piston, don't think they have a 11:1 though. The cheapest place I know of to get one is from JE directly.

As for the K&N 'power kit', don't do it. The only thing the 'kit' makes go faster is your money.

The main jets you get with it are the same jets you can get at your dealership, except they cost more and they have a different sizing system.

The reason? If you need a bigger or smaller main, the only reference size you have is a dynojet size. So you have to go through dynojet to get the jet you need.

My point is you will pay more and depend on one company; also, if you have problems jetting, fewer people will be able to help because they don't know what the dynojet size represents in actual main jet size.

Further, the needle you get with the kit is unnecessary. I feel the power gains you get from 'tweaking' the taper, length are negligible, especally from mild engine mods. Even if you have a majorly modified engine, there is no way dynojet's 'one size fits all' needle is going to give you correct fuel flow.

Instead of getting the K&N 'power kit', just buy a K&N filter and outerwear (or the filter of your choice).

Go to your dealership and buy at least the next five sizes bigger main jets (150, 152, 155, 158, 160). Then Raise your needle by lowering your clip one notch. After all your mods are complete, put the largest main in (160). Riding at a slow pace, put the machine in 3rd gear (I've found that lugging the motor like this gives best results) and accelerate quickly by giving your machine full throttle. If you notice that your machine 'blubbers' and stumbles before you hit the rev limiter, drop the main down to 158 and repeat. Do this procedure until it revs out smoothly. You now have the correct main jet. If you have the 160 main jet in and the engine doesn't 'blubber', then you need to keep going up in jet sizes until it does. Then simply drop down one size.

Your needle setting should be close to the right setting. You can verify that by doing a plug chop.

Sorry to post all this jetting info if you're already aware how to do it, I got a little carried away!

ogre