Rejetting Your XT225 for Higher Altitude

Radical changes in altitude can cause your Serow to gasp and cough and lose performance, or burn your piston or valves. Here’s what you’ll need to install a new jet in your XT225:

  1. Replacement jet - 125-130 for sea level, 112.5 for 5000 ft. and up.

  1. #1 and # 2 phillips screwdrivers

  1. L shaped phillips screwdriver

  1. Flat blade screwdriver or short powerbit to remove and replace the jet

  1. Small needle nose vise grips to clamp on and remove stubborn phillips screws

  1. 4 replacement screws (M4-.70 x 10mm Stainless steel socket cap screws) order extra in case of loss

Acquire and/or make the following tools for reassembly and future changes:

Plug for large rubber tube hole (older models) in case to prevent loss of parts into engine cavity

Various Balldrivers and power bits as illustrated

Tiny reversing ratchet for Power bits

Procedure for initial removal

Turn off the gas. Remove the plastic side covers below the seat on both sides of the bike. Some models you may need to remove the seat for better access.

You’ll need to loosen the carb from the engine boot and air cleaner manifold, remove all the hoses and rotate it out to the left side so that you can get a phillips head screwdriver perpendicular to the screws to get them out.

This process is not only tedious, but the best I’ve ever done (on a good day) is to get one of four phillips screws out that still could be used again.

Replace the jet with the appropriate one, and reinstall the bowl using stainless hex cap screws.

The next time you need to change jets it will not be necessary to remove the side panels, seat, or loosen the carb. With socket cap screws and the tools illustrated here, you can remove and replace the carb bowl and jets anywhere in 15 minutes or less.

A word of caution:

For some unknown reason, the float sometimes sticks upon reassembly of the carb. Before you declare your change finished, turn on the gas and check for over

flow through the tiny plastic tube coming out of the bowl. Take a short spin around the block and check it again. If it overflows, loosen the four socket cap screws holding the bowl and wiggle it before retightening. Repeat until the overflow stops.

Stainless Hex Cap screws are available from our eBay Store, $5.00 for one dozen.

Questions? Comments? Something to add?

Call bierdo at 800-522-6257 or 407-957-5517

or eMail: danoaks (at)

or visit my eBay store

Download PDF of these instructions