I have a 1993 Honda 300ex. Currently it is 100% stock except for a UNI air filter, GBC Dirt-Devil rear tires and a 36 tooth rear sprocket. This summer I plan to take it out to the Dunes, and I want it to perform at its best, but being 15 I have a small buget of about only $400 bucks. So the question is, what aftermarket parts would you recomend to make this a dune ready machine? Along with the parts you recomend, it would be cool if you guys could include the approx price I should be paying for them. I do have an ebay account so that should help me save some money. THANKS

ALEX

 

Here's what I would do:

Exhaust (I'm not a big 300ex person, so i'm not sure if it's worth it to go with the full system or just a slip-on) about $220-340 for a good quality exhaust, do some research first before you choose one, and stay away from DG, Cobra, and FMF.

Remove the airbox lid - free!

Rejet the carb - about $10 for parts if you do it yourself, up to $180 if you have to get a dealer to do it for you. If you have mechanical skills you shouldn't have much trouble doing it yourself, it's just time consuming.

 

Go with a Big Gun or an HMF i wouldn't go with a complete system a sip on is just as good espeacially if you get the HMF u can do away with just a slip on, take the whole air box off

 

I would definately recommend a full system, the stock 300ex head pipe is very small, you need flow to make power. I put a Supertrapp IDS 2 system on my son's quad, got it from Rocky Mt. ATV for $190.00, and got a modified rev limit cdi off ebay for 75, when you open up the intake and exhaust,the motor will rev easier and higher, and the stock rev limit on the factory cdi is very low, you will hit it all the time. Be sure to get some heat tile to put under the fender where the new exhaust goes, I've seen a lot of 300ex's with melted fenders from aftermarket exhauts, I put it on my son's, and have not had a problem in a couple of years. I'm not so sure about Dirt Devils on a small sport quad, a bit heavy and aggressive, my son's ex has Fast Trekkers on the back, handles great, got them from Nebraska tire for 25 dollars each plus shipping. For dunes, look into the Gecko rear tires, only 29.99 each at Rocky Mt. ATV

 

i would either get the HMF white bros combo
or the sparks x-4 complete system
both produce a lot more power

 

Here's a nice list of things to do.

TOP 10 300EX MODS

Here is the old Mickey Dunlap top 10 list from the August 1996 Dirt Wheels magazine. Wouldn't you know it, I found it on my hard drive right after I finished retyping it? This is old so adjust the $$ over time.

HONDA 300ex mods

This information was taken from the Dirt Wheels – August 1996 Magazine.

With a proven record for reliability, good handling and spunky though under stressed performance the Honda 300EX is enjoying phenomenal success. This electric start 282cc 4 stroke thumper has become a leader in the ranks of sport quads. Second in sales only to Yamaha’s BANSHEE, it has propelled itself into this vaunted position because it satisfies a wide range of needs inside a modest package. Can it be improved? Of course it can. It is under stressed engine-wise and it is relatively simple and inexpensive to extract more power and better performance from this vehicle. Here are 10 of the hottest tips that Four-Stroke Tech’s Mickey Dunlap has to offer for extracting the maximum in performance from this versatile off-road ATV.

PREPARE TO ROOST!!

1. I’d recommend installing a pipe first. The stock 300ex uses a very small diameter head pipe. We offer a 1.5 inch head pipe with megaphone exhaust that picks the power up considerably.

2. If you want to realize the full potential of any pipe mod on the 300ex then you need to install a black box mod with it. This will allow the engine to utilize the extra rpm that the pipe will give you.

3. You can get better airflow from the air box to carb by installing an intake tube from the old 350X. We have bought up quite a few of them and sell them for $45. The really do help overcome the restrictive stock 300ex carb air boots.

4. The stock carb (29mm Keihin) can certainly stand improvement. We have a 32mm carb kit we sell with throttle cable for $210. Combined with the pipe and black box mods you will see quite a bit of improvement in the EXs bottom-end, midrange and top-end performance.

5. After I had tried the pipe, black box, airbox and carb mods, I’d opt to install a higher reving cam for more midrange to top-end performance. Expect to pay from $120 and up for a reputable cam for the EX.

6. For more low-end torque I’d go with a higher compression piston kit. They sell for anywhere from $85 to $125 and are a good investment to make the Honda engine pick up power on the bottom-end.

7. My best power for the money would be a big-bore (330cc) kit for the Honda 300ex. We sell our 330 kit for $220 and it is a good value for the buck.

8. Once you start getting more power to the engine, you will need to do something about the increase in heat. We sell a low-priced oil cooler for the EX that lowers the temperature by 40 degrees for only $85.

9. Drill a 2-inch hole in the airbox lid, install a K&N filter and you will see a substantial gain in horsepower. On a stock motor we have found that we use about a #130 main jet at 1000 feet. A modified engine will generally run about a #140 main.

10. If you do modify the engine you will definitely need to add heavy-duty clutch springs to handle the load. We sell a heavy duty clutch kit for the EX for $17. You should also gear up a modified engine with a 14-tooth countershaft sprocket.

Hope this helps

 

first i would buy a hmf slip on cheap reliable loud and add horespower, and they only go for around 250 bucks! and then spend the remainder on a good jet kit and with the combo of the exaust the uni and the jet kit u should get some more hps!!! : )

 

quadxaddict, check the post dates !!! this one is 3 years old, the other 300ex thread you replied to is 5 years old !