[TRX_EX2012]

Hello. I parked the 400ex a while back because its in need of alot of tlc. Needs swing arm bearings, axle bearings, brakes, timing chain and guides ect.

While im at it I was flipping the idea of adding a reasonable priced slip on pipe kit with a cdi and jet kit. I was looking at the Big Gun ES. With this I would probably add a Uni filter.

Anyone use this setup? Does it really add anything? Im mainly just looking to add a little "pep" and keep it relaible. I don't race, just mostly trail ride.

Also, with the insert is that muffler plenty quiet?

 

[tomgodd]

I have an HMF full exhaust on my 400ex. I run a UNI filter with no air box lid......no cdi box rode a few quads known to have them and was never really impressed. The only quiet core exhausts i am familiar with are the FMF units they work well. The only thing is you need to rejet for for the core being removed or installed. IMO more trouble than they are worth. Regardless jetting is the most important part of the who ordeal.

 

[TRX_EX2012]

Ok, probably not worth it then. I might just fab a new baffle tip for the factory muffler replace my "trimmed" baffle. I'd like it to be just slightly quieter. Thanks

 

[marioweldinginc]

i run a White Bros e2 with no arrestor...its not quiet but it sounds mean. i also use a cdi box from an xr250r. it plugs into the 400ex and adds another 1000 rpm. Supposedly its what most aftermarket boxes are. just relabeled stock xr250r boxes...who knew. Also you need to have a good battery. if it turns over too slow when starting it wont fire off. I never had this issue and im using the stock battery from 2004. It has happened to some people though. I use an EHS open lid with outerwears water resistant membrane over it to keep the water out.

 

[TRX_EX2012]

Thanks for the info. Thats interesting about the cdi box from a xr250r. A family member has one so I might plug in the cdi from it just to test out. I'll look into that

I just retired the factory 2000 model battery and installed a new battery from honda about a year and a half ago so I think it should be good as far as that goes.

 

[faris]

I am looking to get some more range out of my 400ex, any ideas besides a oversized fuel tank?

 

[Here 2 help]

Some would recommend re-gearing, but the increase in range will be small (mile or two at best). An auxiliary fuel tank is the best solution.

 

[1hander]

If its just a regular slip on exhaust and aftermarket filters, the only noticeable changes would be engine sound.

 

[marioweldinginc]

If more gas is needed just get a fuel bottle and mount it to your quad. I added a 30 oz. MSR fuel bottle to my quad where the factory toolkit was.

 

[TRX_EX2012]

I decided to just leave everything how it is on my 400ex. Its kinda loud riding it but driving by its not that loud and the sound does'nt carry far.

"faris" As for fuel tank range, not sure if your 400 is stock or hopped up but make sure your carb is clean and tuned correctly. I checked my 400 one time and with fairly easy trail riding and some dirt road it got around 50mpg. Also use good gasoling with no alcohol if its available in your area. My brother's XR650L will get 48 mpg+/- with reg or prem gas with alcohol and get about 60mpg with non alcohol gas.

 

[gerry300ex]

On alcohol, you mean ethanol in gasoline?

 

[Here 2 help]

That's exactly what is meant

Ethanol alcohol, methanol alcohol or any other compound of alcohol (all are flammable) does not have the BTU's per pound that gasoline has. Therefore displacing gas with alcohol reduces power, causes a cooler and slower burn and reduces engine efficiency, but it expands the gasoline supply.

It costs more in natural gas to produce alcohol than the process yields. In other words, you burn more than a gallon of natural gas to produce a gallon of alcohol. Here's a handy chart comparing gasoline to other fuels. You can see how other fuels compare to a gallon of gas - some better, some worse - as you can see, all diesel fuels produce more more efficient power than gas, but all other fuels require higher consumption to produce the same result. Simply put - get rid of the alcohol and improve fuel economy and engine performance. I use VP alcohol free 94 octane fuel in my engines - lawn mower and snow blower included. Without the alcohol, the fuel lasts longer and I avoid the damage to the fuel system that alcohol will cause.

Here's the chart:
Gasoline Gallon Equivalents
Fuel Type Unit of Measure BTUs/Unit Gallon Equivalent
Gasoline (regular) gallon 114,100 1.00 gallon
Diesel #2 gallon 129,500 0.88 gallons
Biodiesel (B100) gallon 118,300 0.96 gallons
Biodiesel (B20) gallon 127,250 0.90 gallons
Compressed Natural Gas (CNG) cubic foot 900 126.67 cu. ft.
Liquid Natural Gas (LNG) gallon 75,000 1.52 gallons
Propane (LPG) gallon 84,300 1.35 gallons
Ethanol (E100) gallon 76,100 1.50 gallons
Ethanol (E85) gallon 81,800 1.39 gallons
Methanol (M100) gallon 56,800 2.01 gallons
Methanol (M85) gallon 65,400 1.74 gallons