New Bike Prep (RFS Motor)

NEW BIKE PREP

1: remove the rear axel/wheel, then remove the chain adjuster bolts, apply generous amounts of Anti Seize Compound into the hole and re-install the bolts. On the bottom of the swing arm about 4 forward of the rear (we need to get up to the hollow part) drill a small (1/8/2mm) drain hole in each side of the swing arm to allow water out! On the inside of the swing arm are large plastic plugs, on the right side you need to slide the brake caliper off to expose the plug, these should be removed and sealed with silicone then re-installed.

2: On chain adjustment do not trust your interpretation of the manuals instructions!! Remove the shock, its only two bolts and if you hold your tongue just right it will slip out. Next block the wheel up to mid travel so the swing arm is aimed at the front sprocket. Adjust your chain at this point so it still has a slight amount of slack in it. Then when you shock is back on make a note of the slack in the chain, remember a little looser hurts nothing, any tighter is a couple thousand dollars in damage! It would be my preference that you never adjust without going thru the process and you certainly do not need to adjust every time you ride! What happens to all KTM riders is some Jap bike rider makes comments that your chain is too loose. DO NOT TIGHTEN THE CHAIN every time someone comments on it! If your bike as O ring chain (typically all except SX models and 250EXC) you can run many rides probably a year without touching it!

3: Remove the screws that secures the shift and kick start levers, apply a liberal coating of Loctite and re-install.

4: Coolant Level: First on the right side of the head near the spark plug is a 8mm hex screw. This bleeds out any air in the head, Unscrew it several turns, it should ozze a bit of coolant. Next on the right radiator is another identical screw, we should do the same except we need to lean the bike to the right! When done the coolant level needs to be checked at the left radiator must be no higher than in that tank, bike upright! If its higher as the engine comes up to temp it will burp excess coolant out onto the head pipe and you will be all panicked that your bike is overheated when it may not even be up to normal temp yet.

5: Oil should be checked at the right side site glass, should be way up, bike upright, flat, level! If overfull expect the bike to smoke and be sluggish.

6: Always check tire pressures, my preference is around 13lbs, the lower you run the more you are prone to flat tires and damaged wheels.

Jetting: In order to import the bike the manufacturers have to jet them insanely lean! This Lean condition is all thru the mid range of the carburetor, bigger pilot & main can not correct it! While there are other needles available that with lots of tinkering it can be corrected I use and recommend the JDjetting.com kit. You will get to the point of enjoying the bike much quicker!
Accelerator pump:
The accelerator pump squirts a huge volume of fuel when you twist. If you where to remove the carb, (gas still in it) and twist the throttle it will squirt gas for about 3 seconds after the twist. This is intended for riding on asphalt! If you are a dual sport guy leave it alone, if you’re an MX guy, or geared low for tight trails the bike will be more responsive if you reduce that squirt down to right around 1 second. There are several ways to do this.
All models you can:
Install an accelerator pump diaphragm, Honda Part #16021-MEB-771 OR Yamaha part # 5JG-14940-19. (under $20). Either of these have a stump on the bottom that stops/limits the diaphragms travel.
Someone makes an AC pump cover called a P38 (for about $80?).
Boysen makes a cover called a quick shot (about $98?)
And there is a trick called the Taffy Mod that involves a wheel spacer from a model airplane, sorry I don’t have any pics.

00-02 models you can:
There is a small steel fork on the right side of the carb, you can pinch the fork closed and with minor tweaking

03-05 models you can;
Drill & tap a hole in the right side of the carb and install a screw to stop the travel of the linkage that pushes on the pump, called a BK Mod.
When it is right it should have instant throttle response, but! Do not bother testing the response until the engine is up to operating temp and driving the bike! With no load on the engine it can not burn the fuel of the AC pumps squirt.

While we are on the carburetor, the engine needs to idle just a bit faster than common, 1,850 being the right number. A lower setting can leave the automatic decompressor still activated and this will kill low end power to the point of causing a hiccup.

Break in: Many theories out there on how to best break in an engine but First and Foremost DO NOT take a new bike immediately onto a trail where your going to get grid locked, crawling along at zero MPH and or pushing up a hill, the new engine is going to make a lot of heat as it breaks in so go someplace where you can maintain some momentum and keep a good flow of air thru the radiator! General routine run it 3 hours, change oil and adjust the valves.

Side Stand: This piece was designed to hold the bike up, period, do not even think about sitting on the bike or kick starting it on the stand!
The RFS (Racing Four Stroke) models (400-525 plus 250EXC from 2002) are pretty well sorted out however new issues often crop up with new models. KTMtalk.com creates a sharing of these issues and cures dramatically reducing the frustrations we had previously, take part & share what you learn!

Crankcase vent hose:
You will get all kinds of people telling you that you can get 40 more horsepower, less dandruff and a bigger, better longer lasting __ if you take the vent hose from its proper location and stuff it anywhere. Assuming you ride off road that hose needs to be routed to clean filtered air. If you have an XC/EXC/MXC, just leave it alone! If you have an SX, I would prefer to see it re routed like the XC type but doubt that I can talk you into it, the peer pressure is parallel to a teen being told to smoke, just don’t do it!

SXF, very important, when you start the engine, do not rev it! Some combo of Hi oil flow, thick cold oil and hi RPM is you start it then rev it has caused some filters to be crushed by that first wall of oil. Let it warn up for maybe a minute before trying to ride off and at your first opportunity buy a Scotts oil filter.
Also the SXF is sensitive to the volume of gas the AC pump squirts, I would contact JDjetting.com and get their float bowl that uses a leak jet, I would try a #75. AND get the Honda Accelerator Pump diaphragm at the same time.

Other stuff;
Most riders consider it mandatory to have (and I would prioritize in this order)
Hand Guards: A simple fall without them can take out a master cylinder, the best come from Fastway.com.
Skid Plate, radiator guards, Clutch slave cylinder guard