Thanks for all the advice guys.

Well I ordered some parts yesterday from Rocky Mt
I got 20x11x9 holeshot xc's on the back and 22x7x10 holeshot xc's on the front.I got the MegaMax II,with header pipe(only $199).The k&n powerkit and a 14 tooth front sprocket.I'm going to hold off on the Black Box for now until I see how it runs,but I still think I got a faulty one from the factory.
Quick question,since I'm changing tire size in the back,does that mean I'll have to change my gearing.

 

Don't change the gearing, because the taller tire's on the rear will actually help u in your situation. You'll have a little faster at the top of all the gears, which is a + for the 300ex. In fact if u don't notice the low end sacrifice i'd even go up a tooth on the front sprocket. Test out the quad after u put the tires on, and before u put the sprocket on. Good choice in tires.

mark

 

Cool Thanks. What about the pipe good or bad.

So you think a 15 tooth would be better.

I checked out your site too,cool pics.

 

I realize you already bought your tires, but just in case you want to know why there are different size tires on the front and the rear axles of your quad. In the rear typically you run a smaller tire to gear down, or to make use of what low end power you have. In the front typically you run larger tires to help your handling, with a smaller tire on front the quad would get squirrelly especially at high speeds.

Hope that clears it up a bit.

 

Thanks blaster,that makes sense.

 

If you are going from 22" rear tires to 20" rear tires you will want to change gearing, especially if you are hitting the rev limiter all the time.

 

Since you bought the 20 xc's holeshots your choice of the 14 t front sprocket will put you right back to stock gearing.You will find that the 14 t front is as big as you can go,you'll have to remove the case saver as it is.you should check into lowering the rear sprocket about 3 to 5 teeth.I think thats what i'm gonna do when i replace my stock 22 in tires.I've already put on the 14 tooth front sprocket and i like the gearing perfect,but if i put 20 inchers out back i'm gonna have to change the rear sprocket.I was told that sprocet specialties has a good selection of rear sprockets for the 300ex,renthal,and sunstar only go bigger not smaller.I heard a fmf pipe on a 300 ex as while back and it sounded real good.Personally i run a supertrapp.Drill about 7 1 inch holes in your box lid close to the outside edge to get some more air,and buy a DG jet kit for 15 bucks and you'll be surprised at the results.

 

Hey Dan I'm sorry I haven't replied to your question any sooner I have been very busy. If you are indeed changing from 22inch tires to 20 inchers and changing to a 14 tooth sprocket you will be about exactly like stock as far as your gear goes.As scotster said you now need to change your rear sprocket to a smaller on as 14 is the biggest I've ever seen for the front.I was always told that 1 tooth in the front was equal to 3 teeth in the rear so with the stock rear being 38 you would need about a 35 or less to see much difference.I'm really not trying to get you to spend money needlessly I am trying to get you to gear it up so you can use a more broad power range,and maybe keep it off that rev limiter.haha. I don't know any thing about the fmf pipe but I'm sure you will be happy with it.And I would be happy with saving 100 bucks too I think a new supertapp is close to 300 now.Well GOOD LUCK !!!

 

hey i got the fmf mega max 2 on my 300ex its great and sounds good too but when i bought mine the fmf plate at the end of the pipe was taken out for less back pressure so i wouldnt recomend doing that just clean the metal silencer things haha hope this helps

 

Welcome to the forums, just fyi check the date of this post it's 10yrs. old