[bigE]

Hi guys! I just bought an 89 RM250 and need some basic info on it so i can hit the trails. 1. What is the gas/oil mix ratio? 2. What type of engine oil should i use and how much do i put in (there is no looking glass for the oil???)? 3. What is used to fill the rear shock (air, nitrous?)? If its not just plain air, what would happen if i filled it with air? The shock is blown and i want to try to refilling it before i attempt rebuilding it.
Any info would be appreciated

 

[Dave2122]

Well you can run Motul oil at 50:1 but it is expensive. Run the best 2 stroke oil you can afford. Bel-Ray, Spectro, Maxima, Motorex are all good oils. The gearbox oil should be just under a quart 900ml give or take.Also use a good motorcycle gearbox oil as the sheer point is higher and will help protect your gears and syncros since 2 strokes are high RPM machines. As far as you shock I would look to E-vilbay for a second hand one that works or just spen the 200 to get it rebuilt.
I suggest you get a manual as you will need to learn the ins and outs of maintaining the bike. Things like grease points, time intervals for parts replacement etc. Clymer is a good manual or the OEM Suzuki manual.

 

[zookerman125]

The gas in the shock is normally nitrogen at 175 psi. You can use compressed air if you want, just remember that air is more sensitive to temperature changes and may condense and turn to water if you don't pay close attention.

I would use air to test it for sure... if it holds air pressure for a few days, it should hold the nitrogen.