I have a 1996 Xplorer 400 and I was wondering if a Polaris 500, 335 or 325 engine could be easily swapped with my 400 2-stroke.

The engine in my bike is fine, it is just that the blue smoke is getting to me. If I sold my bike I would have to put at least another $5000 with it to get a decent 4-stroke 4x4 . . . so I thought about buying an older 4-stroke Polaris quad (for parts) and get an engine swap. I could then sell my 400 motor to a Trailblazer owner to recoup some of the cost.

An engine swap should be possible because look at the SP 500 and SP335 . . . the same bike but with different engines. I know that back in 95/96 Polaris made a Xplorer 500, but it was shaft drive.

Correct me if I'm wrong, but are not the frames on the Xplorer, Sportsman, Xpedition and Magnum the same - except for the rear suspension of course. If the frames are similar therefore the engine mounts should be the same. This would make for a "simple" swap . . . shouldn't it?

Other things I was thinking about were:
- transmission should mate up to the engines in the same location
- carberator linkages may be different
- air box may be different
- hoses are easily rerouted

Does anyone know if this is possible? I know that anything is possible with enough money . . . but is this an economical and reliable thing to do? Any help or direction would be greatly appreciated.

What type of oil are you using? Are you premixing or does this still have the oil injector? Have you checked your mixture? A properly adjusted carburetor on any two stroke will not smoke too much.

I have been using synthetic since I bought her new. I have not had the ratio checked since my initial checkup which was 6 months after I bought her.

The problem is that my wife has chemical sensivities and any amount of blue smoke aggrevates her condition when we ride double. I have also though of putting an exaust snorkle to vent the exaust up and away from us, or some sort or exaust scrubber.

I think my best bet would probable be an engine swap.

Engine swaps usually have a lot of unforseen costs. You would probably be better off buying a different quad and selling yours.

Synthetic oils have less bothersome fumes. You did not say what oil you are running. Also, stock machines are usually jetted rich. If you can jet yours down, this will reduce the smoke. The unburnt fuel in the exhaust may be more bothersome than the oil.