With winter slowly winding down, I have decided to check over my four wheelers and have them all ready for the riding season this spring. Since I now own 3 two strokes of varying years, I want to make sure the oil injection systems give me years of reliable use. I have a 1993 350L 4x4, a 1996 Xplorer 400 and a newly rebuilt 1999 Xplorer 300. I have heard some models have issues with the pumps quitting, leading to top end failure. This is usually tied to the plastic gear going bad or the pump freezing up. What do I look for to keep the pump up to snuff and what year of mine would have the plastic gear and is there a metal upraded replacement if I have one?

Thanks,
Mike

 

You don't have to worry on the 99 300 as the main problems were in the first three years,94-96 on the plastic drive gear. Other than that these old Mikuni pumps were bullet proof and still are. Can't say the same for the 350 and 400 mainly because of where they're locate.Right up front. They catch all the water even through the rubber cover gasket and can corrode and freeze. On those I would pull the plate and check. If they are in good shape,I'd use a good water resistant sealant around the rubber gasket,then install the plate back on.

 

I know the oil pumps work well on all three 2 strokes, just heard horror stories about the plastic gears. What is a good water resistant sealant for the covers on the 350 and 400? I have three bond that I use for the recoil on all the machines, is that sufficient? Once I take the cover off, can I spray something like wd-40 inside it to prevent any moisture and corrosion?

Thanks,
Mike

 

Probably any good Permatex sealant such as this one would do.Gasket Makers : Permatex® Water Pump & Thermostat RTV Silicone Gasket We bought this stuff by the case from our Wurth representative in black and aluminum and imo was some of the best stuff around,but expensive. Wurth Super RTV Silicone Sealant | Demon Tweeks Same for Hylomar sealant.

 

I have the Wurth sealant at our shop. I also have the Mopar brand sealant which I don't know who makes it, but the stuff is awesome. I will pull the covers off the bigger 2 strokes and make sure they stay corrosion free. The only water that would have a chance on getting in there would be from washing the machines or going in the snow for plowing because my four wheelers never get submerged in mud or water, lol.

Thanks,
Mike