Baja / Zhejiang X250 Upgrade Thread

[Weldangrind]

I wish we could still dual sport our dirt bikes here. The gov't took that away from us about five years ago.

[JTHSPACE]

Originally Posted by Weldangrind

I wish we could still dual sport our dirt bikes here. The gov't took that away from us about five years ago.

Wow, what was the "excuse" they gave?

[Weldangrind]

They don't need to. The same ministry that makes the decisions also controls insurance and registration.

[KirkN]

All the electrical work is done. Lights, blinkers, horn, tail & brake lights. Woo Hoo! The handlebar switch even has a cutesy blue LED for when high beam is on. Ha. Don't really plan on doing any night riding, but at least the whole thing looks street legal.

Mikuni carb arrived Saturday. Jets should arrive Monday or Tuesday, along with 16- and 17-tooth front sprockets and mirror perches.

Now I just gotta figure out how to get more fuel capacity.

[Weldangrind]

I really like that LED idea; it means you don't need to add one to the dash.

[JTHSPACE]

NIce job!!

I would be amazed if anyone noticed high beam on some bikes - mine has a 35/35 bulb which is just brighter than a candle. I have ordered a 35/35 halogen to see if it makes a difference. It is a Bosch BA20d fitting so couldn't just swap an H4. One for the future.

Do you need a high beam warning light (legally)? I don't know but I am sure this is a new fangled decision of manufacturers just to add things "because they can"

[KirkN]

OK, here's one that's a bit embarrassing to admit:

Yesterday, when the carb came, the mailman brought it up to the door and rang the doorbell. Great! So, today, when I was all done with the wiring stuff, I realized I had never brought in, nor even seen, any OTHER mail from yesterday. So, out to the mailbox, and there are my jets, stuffed in the mailbox! I was torn between happiness that they're here, and frustration that the mailman, as long as they were coming up to the front door, didn't bring ALL the packages up...

So, of course, I had to jump right on the carb install. Done and done. I swapped out the 20 / 100 (pilot / main) jets that it came with and went with the 27.5 / 112.5 jets from Jets R Us. The idle mixture screw was at 3/4 turns open, so I set it to 1.5 turns open. The needle clip was in the very lowest (richest) notch, so I set it right in the middle.

Started right up perfectly. No choke at all, so I think I might be even a tad rich at idle, but I'm not going to worry about it. Crispy off idle, too. Idle speed was a bit high, and it's a real PITA to get at the idle speed screw with that perimeter frame. At high speed, it's running just maybe a bit lean. I maybe shouldn't have messed with the needle clip at all. Sigh. Or maybe it'll need a 115 main. Changing the main isn't difficult (although I didn't order a 115), but getting at the slide now that the sidecovers, seat and tank are all back on is a chore. We'll see... I'll have to ride it more - I might just leave it the way it is. Haven't looked at the plug, though.

[KirkN]

So, when I was out for a ride, I had my daughter follow behind me in her car - it wound out at about 48 mph. I didn't hold it wide open or anything, but it just sounded like it was revving pretty hard, not having a tach.

So, when the sprockets show up, I'll do a bit of experimenting. I think the 16 will fit with no chain mods, but I think the 17 might require a longer chain. I'm partial to the 17, since I'd like a more relaxed road ride, and it's already geared low enough in first for the casual trail riding I do. We'll see how it performs.

That, and mirrors, and I should be good to go!

[JTHSPACE]

You've done a great job, it looks really good.

[Weldangrind]

Glad to hear that it fired right up for you. Excellent pics.

So, the perimeter frame on the right side blocks the idle speed screw?

[KirkN]

Thanks. So far, so good on the running. It's just a bit lean at mid- to high-rpms. Pops and stutters a bit. Putting on the choke one 'click' makes it better. I don't know if the 'proper' fix would be to raise the needle or use a larger main. Like I said earlier, changing the main is w-a-y-y-y easier than getting at the top of the carb again. The seat, tank & bodywork is a Chinese jigsaw puzzle to get all back together again.

Yeah, the perimeter frame looks neat, but IMO, it's a pain in the behind. Blocks access to the carb, blocks access to the head cover for valve adjustments, makes fitting a larger tank much more challenging.

But don't get me wrong - I'm loving the bike overall. Physically small, lightweight, and very good performance if you keep in mind I'm a fat guy on a tiny machine...

It's funny - I don't know how much of it's 'goodness' is by Chinese design and how much is 'luck' by copying the Japanese, but the thing sure does spec out nice - 250cc 4-stroke, e-start, plenty of charging capacity for add-on goodies like I've done, disk brakes front & rear with twin-piston calipers and braided stainless steel brake lines, inverted fork with separate compression and rebound damping adjustments, mono-shock linkage-type rear suspension, wide heavy-duty footpegs, folding shifter lever, and I'm also impressed with the ground clearance and the sturdy frame rails below the motor with no hanging down obstacles to snag on stuff out in the woods. And for me, I've got less than $600, all in (assuming my time is free).

But, on this site, I'm preachin' to da choir - can I git an Amen!

Kirk

[Weldangrind]

Amen!

Man, I'd be so tempted to relieve the frame where the idle screw is obscured. I'd probably weld in a piece of round tube that I chopped in half, just so the screwdriver would make it in there.

If you remove the tank and seat, is it still difficult to remove the carb and get at the valve cover?

[ripcuda]

Preach it! Very cool looking dirt bike turn enduro!

Do you have an airbox in there? And where does your battery sit? The backend is so slim with huge wheel gap... makes it look really high in the back.

Cheers!

[KirkN]

Originally Posted by Weldangrind

Amen!

Man, I'd be so tempted to relieve the frame where the idle screw is obscured. I'd probably weld in a piece of round tube that I chopped in half, just so the screwdriver would make it in there.

If you remove the tank and seat, is it still difficult to remove the carb and get at the valve cover?

Ha! It's funny you mention that, because I was sorely tempted to do just that with a drill... But, the frame tubing is kind of 'angled' at that point, and it would be tough to drill a hole there with a hand drill. I used a small bit from a bit-driver set to adjust the idle speed. Watch out for the hot exhaust pipe, tho.

No, with the tank and seat off, access to the valve cover is perfectly easy. Carb access to remove it is a bit cramped, but I have large-ish hands. Smaller hands or fingers would make it easier. But, all in all, getting the carb out isn't really any more difficult than on a regular kind of frame.





The thing that makes it a pain is a combination of semi-poorly fitting plastics and my own mods.

First, off come the side covers to allow access to the seat bolts. Then, the seat and rear fender are a combined assembly and come off all together, so all the rear electrical wires have to be disconnected. Then, since the fender with the weight of the tail light 'n blinkers is otherwise unsecured, I've added a zip tie or two to keep it all from flopping around. So, those have to be clipped. The gas tank is a bit of a wonky fit, and the fuel hose has a torturous routing since there's no petcock. I had to add the in-line shut-off valve and again, all that stuff is held in by a couple zip ties here and there. And the tank wants to pinch the throttle cable if you don't get it all lined up just perfectly on reassembly. So, whine whine whine, complain complain complain.

[KirkN]

Originally Posted by ripcuda

Preach it! Very cool looking dirt bike turn enduro!

Do you have an airbox in there? And where does your battery sit? The backend is so slim with huge wheel gap... makes it look really high in the back.

Cheers!

Well, as for the gap, you gotta remember, that's only a 16" back wheel, so the scale might be a bit deceiving. But yeah, it's very slim out back and there's a large gap. Kind of the modern MXer styling.

Yep, there an airbox and battery and all the misc electrics (starter solenoid, misc relays and wiring) all in there. The bike has a bolt-in rear subframe. Directly behind the shock is the airbox. The carb sits in the frame at an angle in front of the shock and the snorkel between the carb and the airbox curves around to the left side of the shock. The misc electrical bits are mounted on and around the airbox.

The battery box is directly behind the airbox. It's a pretty small battery for an e-start bike, but it seems to be doing the job. The battery box is directly exposed to the rear tire. That is, the rear and bottom of the battery box and of the airbox form the rear 'inner' fender, such as it is. Any rocks and mud and such are flung directly at the rear of the battery box. The bottom of the seat pan has a bit of a lip that extends down behind the battery box, protecting it a little, but not much.

Here's some pictures from when I was first resurrecting the thing.