Baja / Zhejiang X250 Upgrade Thread

KirkN · 05-28-2015, 09:41 AM

Well, since the tires are nearly new, I'm not going to replace them yet, even though they're not DOT-legal. Gonna have to take my chances there. Gotta go careful around the corners on the street as well.

Equipment I'll need is lights, blinkers, horn, mirrors. Some other stuff will be valve clearance check/adjust, gearing changes, carb upgrade to Mikuni, oil change.

Here's the 'universal' headlight I have. My son picked this up somewhere and he gave it to me. It has a high/low beam, and even has integral blinkers. You can also just catch a glimpse of the tail / brake / license plate assembly I'll be using sitting on the bike to the right in the background.

I ordered a universal headlight/hi-low/blinker/horn switch off ebay, and while I wait for it to show up, there's other stuff to do. This bike, for some reason, came with the kill switch / e-start button assembly mounted on the LEFT handlebar. Now that I've got the light switch assembly coming, I decided to swap sides so the switches will all be in their "normal" places.

On this bike, the front brake lever assembly had what was a safety switch. You were supposed to have to squeeze the brake lever for the e-start to be able to work. I bypassed that, but it left a perfectly nice switch available for use as a brake light switch. I'll maybe one day add a rear brake light switch. I've seen hydraulic switches that install right at the banjo bolt in the system. It's not top priority, since I'll at least have a brake light off the front brake for now.

KirkN · 05-28-2015, 10:15 AM

I decided to check the valve clearances while the tank was off. This bike was ultra-quiet from the top end. Plus, it never did like to kick-start.

Good thing I checked, too. Intake and exhaust had basically zero clearance. Couldn't slide the 0.002" feeler gauge in at all. So, I reset 'em to 0.003" intake and 0.004" exhaust. Slappy valves are happy valves and all that.

I was surprised at the difference - it will kickstart right up first kick. I use the e-start, but it's very nice to know the kicker is an option now.

KirkN · 05-28-2015, 10:33 AM

The bike also needs a gearing change for street riding. It came with 15/48 gearing with a 420 chain, and it tops out at about 35 ~ 40 mph in 5th. I've got a 16-tooth front sprocket on the way. I bought one for a Honda SL125, since they're interchangeable.

The rear sprocket, though, is a mystery. I've read other threads that talk about measuring the center hole diameter and the bolt circle dimensions and ordering based on that. I did an on-the-bike measurement and got about 2-1/16" for the center hole. Bolts are 2" apart and about 2-7/8" apart on the diagonal.

Anybody have any details or interchangeability hints?

I'll make a decision on number of teeth based upon how it drives with the 16-tooth up front. I'm thinking 45 or even 42 or so.

And that's about all for now. More updates to come when parts start arriving. Woo Hoo!

Kirk

05-28-2015, 09:41 AM	#1
KirkN Join Date: Nov 2014 Posts: 50	Well, since the tires are nearly new, I'm not going to replace them yet, even though they're not DOT-legal. Gonna have to take my chances there. Gotta go careful around the corners on the street as well. Equipment I'll need is lights, blinkers, horn, mirrors. Some other stuff will be valve clearance check/adjust, gearing changes, carb upgrade to Mikuni, oil change. Here's the 'universal' headlight I have. My son picked this up somewhere and he gave it to me. It has a high/low beam, and even has integral blinkers. You can also just catch a glimpse of the tail / brake / license plate assembly I'll be using sitting on the bike to the right in the background. I ordered a universal headlight/hi-low/blinker/horn switch off ebay, and while I wait for it to show up, there's other stuff to do. This bike, for some reason, came with the kill switch / e-start button assembly mounted on the LEFT handlebar. Now that I've got the light switch assembly coming, I decided to swap sides so the switches will all be in their "normal" places. On this bike, the front brake lever assembly had what was a safety switch. You were supposed to have to squeeze the brake lever for the e-start to be able to work. I bypassed that, but it left a perfectly nice switch available for use as a brake light switch. I'll maybe one day add a rear brake light switch. I've seen hydraulic switches that install right at the banjo bolt in the system. It's not top priority, since I'll at least have a brake light off the front brake for now.
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05-28-2015, 10:15 AM	#2
KirkN Join Date: Nov 2014 Posts: 50	I decided to check the valve clearances while the tank was off. This bike was ultra-quiet from the top end. Plus, it never did like to kick-start. Good thing I checked, too. Intake and exhaust had basically zero clearance. Couldn't slide the 0.002" feeler gauge in at all. So, I reset 'em to 0.003" intake and 0.004" exhaust. Slappy valves are happy valves and all that. I was surprised at the difference - it will kickstart right up first kick. I use the e-start, but it's very nice to know the kicker is an option now.
	0

05-28-2015, 10:33 AM	#3
KirkN Join Date: Nov 2014 Posts: 50	The bike also needs a gearing change for street riding. It came with 15/48 gearing with a 420 chain, and it tops out at about 35 ~ 40 mph in 5th. I've got a 16-tooth front sprocket on the way. I bought one for a Honda SL125, since they're interchangeable. The rear sprocket, though, is a mystery. I've read other threads that talk about measuring the center hole diameter and the bolt circle dimensions and ordering based on that. I did an on-the-bike measurement and got about 2-1/16" for the center hole. Bolts are 2" apart and about 2-7/8" apart on the diagonal. Anybody have any details or interchangeability hints? I'll make a decision on number of teeth based upon how it drives with the 16-tooth up front. I'm thinking 45 or even 42 or so. And that's about all for now. More updates to come when parts start arriving. Woo Hoo! Kirk
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