My Jinlun JL250P Sport Bike

[latentboarder]

I have a few pictures floating around on my PC.

My Bike:



This is a 2011 Jinlun JL250P motorcycle, 233cc 253FMM inline twin engine with inverted front forks and full sport fairing. (Engine is identical to a Honda CMX 250)

This bike has the following mods: Replaced stock mirrors with Yamaha YZF 2003 mirrors, anti-vibration black fuel tank trim, anti-vibration fairing shims, custom logo decals, Toyota PCV valve fittings in place of stock tank mounts, replaced rubber fairing fittings with neoprene washers, some minor touch-up paint to cover shipping scuffs.



Photo was taken in Linwood Michigan, that's Lake Huron in the background. It's the third largest freshwater lake in the world. 8)



One more:

[SpudRider]

Thanks for posting the nice photos, LB; your bike looks great.

P.S. If you reduce your photographs by 50 percent, this thread will be much easier to read.

Spud

[latentboarder]

Ah, sorry about that. I'm new to this forum system... :oops:

[SpudRider]

Originally Posted by latentboarder

Ah, sorry about that. I'm new to this forum system... :oops:

It's not a big deal, LB. I enjoyed your photos, and we are very glad you joined us.

Spud

[SpudRider]

It's great your bike's engine is identical to a Honda CMX 250. My Zongshen 200GY-2 has an engine virtually identical to the engine in the currently manufactured, Yamaha, TW200 motorcycle. Finding engine parts is never a problem for such a motorcycle.

Spud

[Weldangrind]

That's a really nice looking bike. Thanks for the pics.

[latentboarder]

Thanks! I love this bike, problems and all. The only issue she has that I haven't fixed yet is an inaccurate tachometer, probably an electrical issue somewhere causing it. Aside from that, it rides very smooth. It builds only about 18hp, but it's geared low so it accelerates fine. Could use a 6th gear on top, it's just a 5 speed and maxes out at around 80-85mph stock. I have a smaller rear sprocket to solve this, but haven't felt the need to use it yet. Perhaps when I swap for a performance chain this winter I'll switch the sprockets too.

If the weather is nice this weekend, I'll take her out and post some video of the bike running. 8)

[Weldangrind]

It'll be interesting to learn where the trade-off point is in terms of gear ratio. Eventually, you'll get to the level where the motor no longer has the power to push the bike at a given high ratio, and you'll actually have a lower top speed.

If you care to, feel free to start a thread in the Street section that shows us your mods so far. We rarely see new members who are already experienced China Riders; most people grow along with the forum, having had some Japanese riding experience at most.

[FastDoc]

Considering a usual Chinese '250' street bike can hit maybe 70 at the most I'd say he's going great already and I would not mess with the gearing at all!

[2LZ]

Originally Posted by Weldangrind

It'll be interesting to learn where the trade-off point is in terms of gear ratio. Eventually, you'll get to the level where the motor no longer has the power to push the bike at a given high ratio, and you'll actually have a lower top speed.

As opposed to Doc, I felt my Q, in my areas conditions, was geared way to tight. My first gear seemed almost useless since I didn't ever really trail ride it. I'd start in 2nd and top out quickly.

I went overboard and went with the smaller rear and larger countershaft....and indeed.....it would run out of power up top. I can't remember... I think a 16/44???

I dropped the countershaft back to the stock gear and kept the 44 and not only did it accelerate quicker....but surprisingly enough, it could wind higher so I gained a taller top speed by about 5-8 mph....and it was way more comfortable there.

[FastDoc]

Oh we agree for a Q, 2LZ. Especially the XF.

But this bike in question already goes way over 70, which is about the fastest '250'cc CB I'm familiar with. That's why I figured it's geared well already.

[Weldangrind]

That's a fair point, Doc. I've never heard of a 250 CB hitting 85mph.

[SpudRider]

Indeed, that bike is performing very well. I'd be very reluctant to mess with the sprocket ratios.

Spud

[latentboarder]

Well, that's a claimed 85mph. I know for a fact that my bike is about 5-7mph slower than indicated, since I ran it against a friends car. But yes, I'm very happy with it's highway speed. It's just the expressway that causes trouble, since the speed limit is 70mph and most people drive about 75. If you need to pass, you don't want to be at redline pushing 80mph (actual).

Couple that with an insanely low first gear and it might be worth it to switch. The existing rear sprocket is 36 teeth, the new one is 33.

To gear your bike properly, (or at least semi-accurately) try this site out:

www.gearingcommander.com

For the Jinlun, you need to find the Roketa MC 113 2011, it's the same bike. You'll also need to drop max rpms to 8500 from 9000 on the Roketa MC113, since the manual from that importer incorrectly lists the redline as 9000rpms.

After changing that, scroll down the page and you'll see a list of gearing options with changes to drive and counter sprocket. You can also make custom changes and see the results immediately. This is an incredibly cool page for bike modders. 8)

Sadly, the counter sprocket is difficult to change on this bike. The crankcase gets in the way of a larger one, which is a shame since it's identical to a Honda Rebel CMX250 C-sprocket. The rear sprocket is unique and has to be custom made, but it's easy to put a smaller one on and then cut the chain down. (or swap chains)

[mp43sniper]

Where did you order your bike? I've seen some that have different tank decals but like yours the best.

Thanks!
Craig in PA