TRX 250R -Intake Modifications

The Air Intake & Shifter Setup

I don't ride in wet conditions very often. If I did I might have a different approach to getting air in my TRX. As it is - even with rain coming down and some spray coming off the tires there is enough protection that the water does not touch the air cleaner or get sucked into the motor. I watched this condition very closely at Glamis recently while riding in the rain.

With the airbox removed the air cleaner is more exposed to the elements. I also noticed it was considerably louder this way. Many people accused me of having a 500 cc motor because of it. This view shows the placement of the rear brake reservoir - it's hanging from a small bracket that's been welded to the frame. I like the Outerwear over the K&N filter.

Another small bracket welded here hangs the air snorkel assembly and K&N. A single bolt welded to the connecting tube is plenty to hold it together. A tie-wrap holds the Outerwear in place. I drilled a couple of holes in the bracket to lighten it. The overall length of the intake remains the same as stock. Clearance is tight but it clears the frame by about 10 mm.

The connecting tube is made from a 1 1/2" section of propane tank, it is the exact size (the short green ones used for small gas grills).The fatter top of the Ohlins shock made me relocate the hole that I attach the connecting tube to. Over all it's light and effective and simple in design.

Here is the best part I ever made for my TRX. I always hated the position of the stock shifter. It was always to high or too low. I cured my shifting problems the day I added this piece. The dark area near the foot peg bolts is one of the places my frame broke - click here for story.

Swifter Shifter
The shifter placement and my size 12 or so boots never got along. With its linkage I can adjust the shifter tension, height and throw. On the inside is an adjustable link using a heim joint. It hangs from the swing arm pivot bolt which has been reversed in position and is retained by a circlip. The inside is triple o-ringed to keep the sand or dirt out. I squirt it with WD 40 every so often to keep its action smooth. Because of its mechanical leverage I was able to let it have very light tension AND a very short throw.

Front sprocket changing requires one additional step. I have to remove the circlip to let the shifter swing out of the way. Other than that there are no additional problems.

The switch in the photo is the trigger to the Dale Walker Electric Shifter. It lets me shift gears under full throttle conditions without letting off the gas or using the clutch. I didn't like the thought of having the internal gears cut - this does just about the same thing.