MarkinAR

Yes. hold the throttle wide open and yank it a few times.

good investigative work! I use Babbitt's or Partzilla to find the part number of what i need and then search ebay, amazon, etc and usually find it quite a bit cheaper than dealer. Just have to dig through the diagrams and find what you need.

maybe Babbitt's online or rocky mountain ATV for OEM.

About any coil wire should work that is long enough. Usually you can unscrew the plug boot and unscrew the wire from the coil and replace it. I've used skinny auto plug wires before. Anything that will fit into the plug boot and has a good thick silicone shield.

Great work, quite the improvement.

Pretty sure that's the spring for the decompression mechanism. Without it, the dowel just bounces up and down in it's hole....not a great idea. It's probably pressure specific also, so you probably need the OEM spring.

I usually start by testing the pig tails at the headlight with a test light to see if there's voltage there. If not, then go upstream from there. Next stop is the headlight switch to make sure it works and on up the line.

Always rebuild an OEM starter over putting a cheap chinese one on.

I have read that some of those had a weak ground wire. Might try adding a heavier gauge ground wire to better ground the battery to the frame. You can also check battery voltage while running; it should exceed 12V if the stator is doing it's job.

Thanks for the update @JacobSlabach. Front discs really are a massive upgrade. Funny they would be on the 420 OEM but not the Rubicon. I have a little 300FW I've put together and took it submarining this last weekend. Great little bike, but no brakes as is normal for a 300. It's going to get front discs at some point though whether I buy the SATV kit or fab up some off another bike.

There aren't any oil passages around exhaust studs so that's not where the oil is coming from. I'd bet there's a rocker cover right above the exhaust port and it's leaking there or it's leaking down from the head. Shoot a few pics and let's figure it out.

In central AR, it's pretty much mud parks. There are a few trail central parks in the northern part of the state though. my preference is mud and water. Little 300FW doesn't much care for trail rides but it's a monster in mud and water.

Good work. newer 400EX is the same stupid screw. You're supposed to have the D shaped tool from the dealer...or cut a slit like you did. it seems that most carbs i've seen the factory adjustment is 2 1/4 - 2 1/2 standard. Maybe that's kind of industry standard.

Odd...is the sidewalk your property? Here sidewalks are generally on the city easement and city property. I'd get a bottle of sidewalk glue from the hardware store and just line the crack and you're good to go for several years.

you could probably replicate function with either hard PVC or flex hose. That's what I always do on an ATV that may see water/mud anyway.

Last piece was lights. Hate not to be a purist but man do cheap LEDs make some light.

a 2 wire coil is pretty much a 2 wire coil. I'd look at the run/stop/run switch, make sure the coil is grounding on a clean surface, etc. Likely to be an electrical gremlin if more than 1 coil won't spark.

Might want to gut it and see what is really broken if you haven't already. Pretty unusual to strip the gears AND the axle, it's normally one or the other. Had a Honda 420 apart recently that I just knew the ring and pinion was blown on. Busted it open and it turned out to just be one bearing blew up that let the ring gear move to the side a 1/4 inch which wasn't enough to mesh with the pinion. OEM Yamaha ring and pinon is only $200 or so, you can probably pick up an aftermarket for a hundo.

There's no real magical cubes = jet sizing formula. Given that every motor is a bit different with it's own personality you just have to do some trial and error. Seat testing, plug chops. To really tune it just takes a bit of time and testing. Take into account type of exhaust, air filter type, airbox or not, elevation, fuel type, pilot and main jet setting, needle clip position, fuel screw position. I did some google searches and a few people have asked the same on some Yamaha specific forums, so maybe you can find something to get you close.

Can't beat the giddyup of a Can Am. Check out MudPuppy on Youtube for a run down of the issues he had with a XMR1000. Can Ams all use the same harness and have common issues. They're not bad at all, you just have to be prepared to do a lot of fixing if you really run them hard.

Depends on how and where you ride it. With a lot of mud and water use Can Am's don't do so well. The wiring harness is ran terribly at the front and is bad about wearing holes in the harness, belts are garbage if they get wet. They just aren't as reliable as a Honda. However, they do haul as*. Way more as* than a Honda. So to answer the question: who knows.

Or..if axle bearings aren't shot just rebuild the diff and send it on it's way.

Arctic Cat has been a really good workhorse historically, but they're not ideal for a mud machine. If you want to submarine it and throw it into the bounty hole, stick with Honda 300's or at least a 420. Arctic Cat is a great bike but there's no user community to support them as mud bikes. They're great for trails or farm use.

Usually the cheap rebuild kits don't have the axle bearings, however the axle bearings are normally available at parts stores. You probably have everything for the diff but missing stuff like bearing #9 below. I've had great luck measuring the in/out/width on a bearing, hitting google to find a number to cross, and then calling the local parts store. Bearings are only about $8 in a parts store and are pretty easy to find.