how fast will my 300ex go with my hmf slip on and 125 main jet also how fast will it go with the hmf jet and air filter and 12 tooth front sproket..............also with thoughs mods will i be able to beat a stock 400x?

 

I'd say it would run between 60 65. You would run with a stock 400ex to 3rd gear then the ex would pull away

 

These types of posts are such a waste. Do a search you will find an endless supply or arguments about how fast does "insert quad here" go" If you want to know get a GPS, strap it to your bike and find a nice open area. People will always give ridiculous claims as to how fast quads go and you will always find the miracle bike that goes at least 10 mph faster then everyone else's.

In my dealings with 300 ex's and 250X's 55 is just about it stock. A slip on pipe isn't going to gain you a whole bunch of speed and going down a tooth on the front sprocket would only make it go slower. When I use to have a 250X STOCK and my friend had a new STOCK 300EX we were about even at 55 on pavement. I added a full pipe re jetted and went to a 14 tooth front sprocket and saw just a couple MPH gain...hit 60 one time on dry pavement on flat going.

Back when I was younger an had the 250X I was all about the top speed numbers and who's the fastest. Now that I am not an immature 13 year old I can see that it was dumb to care about this type of stuff and I find it so wasteful now. This forum should be used for useful tech questions and info regarding the purchases of at's not a bunch of flaming and "my 300ex is the fastest" and all this other crap. I used to enjoy coming here reading peoples question and answering them if I could, or at least try to learn something from them. Seems like nobody cares anymore and just wants a huge post count. There are still a lot of good people here but they seem to stay quiet these days.

 

Thank you, SFA. I couldn't have said it better myself.