I picked up an Xplorer 300 a couple weeks ago that the owner didnt want because he said it had no compression and was thinking it was going to be expensive to fix. Well I got it home after bargaining with the guy and cleaned it up since it has been sitting in a shed for roughly 7 years. It had a plow and a winch that I didnt know if it worked so I took that all off and had that sold that night for almost what I paid for the four wheeler. Ordered a complete gasket set, crank seals and carb kit. Let it sit in my shop for the last few weeks because I was busy and was on vacation for the last week but got time this weekend to start the tear down. Got all the front plastic off and gas tank as i went to grab the coil wire and was shocked that the spark plug came right along with it! Guess the guy never checked to see if plug was in making it not build any compression. I put the plug back in and sure enough, she had compression when I pulled it over. Busted out the compression tester and spun it over. The gauge read 125 pounds. I guess thats in the service limit and not bad for an engine that sat almost 7 years. I know it had spark because the guy I bought it from was reaching up for the plug when I pulled the recoil and he squealed like a pig when I pulled it. Guess that was a good thing I didnt realize he was grabbing for the plug when I did that or he may have not wanted to deal so much on the price. I checked the spark after I found out the plug wasnt in and had a good solid spark. Decided to tear the motor down the rest of the way to check everything else and was planning on replacing all the seals and gaskets anyways. The rod and crank bearings have zero play and I measured the cylinder and got reading around 74.6 and 74.7 mm. Still within the service limits but kinda right in the middle. What would you guys do? Punch the cylinder and upgrade to a Wiseco piston and rings since I am this far? Money really doesnt matter because as of right now, I have roughly $75 in this thing, believe it or not. My wife thinks this is funny that this thing fell into my lap like this and it was something so simple that I even overlooked it when I was looking it over. Even though she thinks its funny, she still is like every other wife and wants thing done cheap, lol. I think if I replace the piston with a good one, I will have a good machine for many, many years versus just slapping it together and maybe getting a few more years before a rebuild.

Thanks,
Mike

 

Man,not often you luck into something like this. Plug not in the hole.. Compression was ok at 125,BUT since you got it torn down and only have 75 bucks in the blame thing to begin with,I'd go ahead and bore it to the first over size and then you'd know for sure what you have. You're going to have to have a new head gasket and base gasket any way. Plus wives are always cheap! I've been married to a cheap woman for almost 45 years.. At least when it came to spending money on my toys and guns over the years.. Women just don't understand a man's logic on mechanical things.. I swear their brains are wrapped counter clockwise to a mans brain..

 

Just perfect timing I guess. Not a big demand for older two strokes in this area and this time of year ATV plows are a hot commodity. I had two xplorer 300's to choose from. This one and a 97 that was in decent shape but needed tires and a carb kit. Came with a winch and plow just like this one. The guy with the 97 was fairly stuck at around $400 so I talked the guy with the 99 down to $200 and sold the winch and plow for $175. When I get this one running, I might give the guy with the 97 a call and see if he is willing to deal a bit. Cheaper than going to the dealer and making payments on a new one for the next 5 years I guess.

I see a lot of different brands of pistons for sale online and am only familiar with Wiseco for small engines, but what do you think about the others like Namura, Athena and WSM? Wiseco seems bulletproof but the other brands are more economical for price. I know with some stuff its better to go with name brand such as using a Polaris brand for the drive belt, but it seems like when it comes to pistons, people use whatever is cheap.

Thanks,
Mike

 

Wiseco is the best,period! I've also used Namura and Athena but not Wsm. Both of these are ok as oem replacements and Namura has a teflon skirt coating,but again not as strong as the forged Wiseco.

 

I got time to get to the machine shop today and they had a Wiseco piston and they bored the cylinder out for me as well as fitted the rings. Now I am ready to bolt this little 300 back together. I have a new gasket set that came with the crank seals. One rubber and one metal. Which side is which? I havent taken the recoil off but the clutch side has a rubber seal on it now. Does the 300 have that goofy looking nut on the flywheel side that i have to use a bronze punch on to work it loose? This little 300 looks like a breeze to work on compared to the 400 I did last winter. I will premix my first tank of gas and hope all goes good by the end of the week!

Thanks,
Mike

 

Metal seal goes on the stator side. No,the 300 doesn't have that slotted nut. The simple little 300 piston port engine is quite a bit easier to work on than the complicated 400. When you get it back together mix at least 2 gallons 50/1 to help with the break in. Hold the oil pump arm all the way up at an idle for a couple minutes or so after you first crank it. This makes the oil pump flow wide open and usually you can see the oil go through the line to the carb.Once there you can usually tell by the extra smoke from the exhaust.

 

Got the 300 all back together today. Both crank seals, all new gaskets, fresh carb rebuild, rebuilt the starter and put a new key switch in it while I had it all apart. I don't think I needed to go through it this far, the carb was the only thing that was seriously needing attention but I figured since I had it all apart now, a little money spent would make it last for quite awhile. Went to start it but it didn't want to fire right away so I was a little worried, but I soon realized I didn't have the choke set properly and once I got that set it fired right up. Everything works as it should and it is definitely quieter than my 400 in the exhaust sound but is a tad buzzier sounding, lol. I will break it in easy and have it all ready for camping season, the only issue I have to work in is the lights on the handlebar pod don't light up. The neutral, reverse and high beam don't light up as they should and I'm not sure if that has anything to do with the battery because it is pretty well not holding a charge at all. The AWD button was sticky but I took it apart and cleaned it and works like a charm now. Guess it's just the gremlins of having it sit for close to 8 years, lol.

Thanks for your wisdom OPT,
Mike

 

These little dash bulbs are the first to go if you have a weak or dead battery. Voltage from the regulator has to go somewhere if the battery isn't able to take it and these bulbs offer the least resistance and pop.Polaris 4030042 Indicator Dash Bulb Magnum Others 1995 1998 New | eBay You still stole this old clean,noisy 300 for 75 bucks..

 

I wouldn't consider it "stealing"....more like giving it a better life, lol. Unfortunately if I didn't buy this one, the guy who had it probably would have stuck it back in the shed to let rot some more. Drive it around the shop today and everything is super tight and the AWD works flawlessly. Just little things to address now such as the indicator lights, a good grease job and I had to replace the fuel line from the tank to the carb. Had a spot of fuel in the floor this morning and found the line was a little brittle. Can't believe I missed that when I put it together.

Thanks,
Mike

 

Considering it's worth around $1500-1700 by KBB I wouldn't mind finding a few like this myself. Fix em up, and out the door with some good spending money in my pockets.. Good luck with it whether you keep it or sell it.