New to the XT350

First post but been hiding in the shadows for a bit, reading and gathering info.

3 months ago I choose to get into dual sport riding after tagging along with friends. I purchased an 85 xt350 with 29,465 miles on it for $100.00! Oh and did I mention it didn't run, and it was in pieces! I had no previous bike expericence but have grown up with mechanics and rebuilding our 4 wheeled friends (cars and trucks not ATV's) It's always hard taking on a project someone started, so 3 months, $367.82, and lots of searching online later I have the bike back together, rebuilt top end and it just fired off last night and purred like a kitten. Ran it through some warm up and break in cycles, then did my normal pull things apart and check how its breaking in. All looked good but noticed that it appeared to be running a little lean. Plug was a little light.

Correct me if I am wrong but this sounds like its a typcial issue with these bikes?

These seem like the correct steps people are taking: *please correct any miss info i've gathered.

1)Air screw - back off another 3 turns or so.

2)Drill out pilot jet at least one size larger.

3)Drill main jet out or find xt600 jets that work (i believe part numbers are floating around)

Anything else to check? Thank you all for the help you have been silently giving me the past 3 months.

OH, and I am not sure if this should go here or in the vintage section sorry admins if I posted in wrong spot

You're in the right place.

They come plenty lean from the factory, and any decent mods makes them leaner.

Others will chime in about the specifics.

You usually don't have to drill out the pilot, but be sure it is clean: they like to plug up, and so do the mains. I think the pilot mixture screw current standard is 3-4 turns out; remember, it is mixture like an older Rochester four barrel, not an air screw like a lot of motorcycles. It is what mixture you allow around the slide when the throttle is closed. If the screw is on the engine side of the carb, it is like that, if on the air filter side, it is an air screw, controlling the amount of air to the pilot circuit. These control the amount of already mixed fuel and air that gets out of the very small hole on the downstream side of the carb, when the slide is almost closed at idle.

Keep track of the valve clearance, and watch out for cracks in the carb mounting spigots. (most call them boots)

Sometimes the secondary carb slide (the diaphragm) gets a hole it it from backfiring due to a really lean condition. Don't let it get that lean.

Put anti sieze on the plug threads, and refrain from removing when the engine is hot, or one day, the threads will come out too.

run quality motorcycle oil, and change it regularly. I would suggest a synthetic like the Mobil1 racing 4T or BelRay. Don't run the thick cruiser oil, run the 10-40/10-30 stuff.

Good luck.

You can leap-frog drill the mains with a precision drill set or go find the TT350 jets or the XT/TT600 jets. Look at Yamaha's web site for part numbers. they're available, and easier than drilling.

-3-4 turns out from bottomed on the screw.

-Don't drill the pilot.

-Shim the needle

-130 main jet from XT600

Sounds like you got a good deal in the long run.

I think I got a good deal. From what I've read, the bottom end of these bikes seem pretty bullet proof, but the top end needs to be maintaned. I am also surprised at how little support there is for these bikes. Seems like a good size to have as a dual sport. I live in the northwest where you have to ride streets to get to trails and the trails are tight with trees. 600's seem too big for trail riding and 200's seem too small for long street rides. Since this is my first bike ever I figured the 350 is a good starting size to learn on.

Any other websites out there that people find usefull for the yamaha dual sport bikes?


I love the 350 size. It should work great for you. It tractors up hills like crazy.

The only other good resource i've found is on advrider in the thumpers subforum. "The XT350 Thread" is a monster, but very active and full of good info and pics. If you start at the beginning and read through it, you will know just about everything there is to know about these bikes. (fyi, I'm Skidmarx over there.)

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