As for jetting, my son's has a UNI filter, Supertrapp IDS2 pipe, and 4 1" holes in the lid, and I am running 2 sizes over on the main, and one bigger on the pilot jet, the Hondas seem to be jetted lean from the factory, going up one on the pilot jet helped with cold starting and bottom end throttle response. HondaRider, I find it hard to believe you run without the lid and not jetted up for that, the stock set up only draws air from 2 little frame tubes, with no lid, you are increasing air flow many times over, that would make it very lean. How did you measure your top speed? stock, my son's 300ex would be left far behind by my Wolverine, with the filter,jetting,pipe and higher revving cdi, I can still pull away, but not near as much, so that still puts the top end below 58.

 

Why would u have to change the pilot jet, as soon as u hit the throttle the pilot jet realy doesn't do a thing. And as far as no air lid its just fine look at YFZracer12 he took the air box completly off without rejetting. And we clocked it with a sportsman 500

 

The pilot jet is very important for idle, throttle response off idle, and is in use up to 1/4 throttle, not just for the base idle, and as I said, Hondas tend to be a bit cold blooded, my son's was a little hard to start cold, with the mods it seemed a little worse, going up one on the pilot helped a lot,warms up faster, and the throttle response off idle is great, no hesitations or bogs, the stock exhaust is very restrictive, replacing that and modding the air box and putting a UNI filter in will lean it out, If you are still running stock exhaust, you may not need much more jetting, the restriction in the stock pipe will limit the air flow through the carb anyway. As far as top end, my readings were with a GPS, way more accurate than a quad speedo, I'm sorry, but you aren't getting close to 60 with a near stock 300ex, if my Wolverine can dust a stocker, and pull away from a modded one at 58, that tells me the top end is still under 58, and no, my son's isn't a worn out beater, it is a 99 in excellent condition, runs great and is geared to stock specs. Not trying to start an argument, just telling you my direct experience and testing results.

 

We just clocked it agin with a 04 duramax truck at 9:30 thismorning and i was at 57. your sons is a 99 mine is a 03 im sure honda has done things a lil different sence then. And if u want better throttle response cut coils off the carb spring

 

For laughs, I wrote Uni an email and here is their response:

Hi,

Normal rule of thumb is go 1-2 larger on the main and move the adjustable needle clip down to richen that up. Best bet is to check with a local shop in your area.

Thanks for going with UNI FILTER.

I would have to agree with this based upon how our is acting.

 

inthedirt if you want to get real results come to nebraska and come to the local trag strip or the one at my house bring your 300ex and your "uitility" and we will race of a christmas tree and i will show u that i run 57-58 mph. Pluse its pretty much all in the rider, i do nothing but sit at the strip at the local strip with other 300ex's 350 raptor, and beat them i have beat one 350 warrior YES some do beat me, but the main point is i top at 57-58mph. and with our christmas tree u don't have some person waving a hand u have 3 or 4 guys in a line and wait for the green light.

 

I ment 95wolv