Picked up the Lifan Xpect

[TominMO]

Thanx mt77, very useful advice. I'll get on it.

BTW what is that red connector that is not connected to anything?

[braindead0]

Originally Posted by TominMO

Thanx mt77, very useful advice. I'll get on it.

BTW what is that red connector that is not connected to anything?

Probably the 'make it run right' connection ;-)

[mototech77]

TominMO: The red connector is the diagnostic port. You can get a Honda 6-pin to OBD2 adapter cable to interface with the ECU (not to be confused with other 6-pin adapters like the KTM’s use). I use an ELM327 clone WiFi adapter with Car Scanner app on my iPhone and it works pretty well so far. I haven’t had as much time to fiddle with it as I’d like, but I’ve been able to do things like verify that the throttle position sensor was zeroed, etc.

Braindead0: Man, I wish that were true! LOL

[TominMO]

Wow, thanks again mt77!

[TominMO]

Well, long story short, it was apparently removing the evap canister that caused my issues. When I reinstalled it, it started up immediately, no more cranking or giving it gas. Changed the oil, started the bike up to circulate said oil; immediate starting again.

Besides draining from the bottom plug (17mm socket), I also drained the left side where the screen is (24mm or 15/16" socket). I wanted to check blockage. The screen was fine.

(Never did drain the gas BTW; always do the cheap and easy troubleshooting first.)

Went for a short ride (immediate startup again) and it performed perfectly. Even took it up to 8K RPM for a second to check fuel delivery. Also no popping on decel, which it did just a little, after removing the canister.

[braindead0]

Typically evap cans have a vacuum line connected to them, this is so they can 'regurgitate' the collected fuel into the intake... If you removed the evap and didn't cap off the vacuum line, that might explain the issue.

Good that you found the cause! And good job on the troubleshooting...

[mototech77]

Great to hear the positive results! Sure beats having to mess with the fuel tank.

[TominMO]

Originally Posted by braindead0

Typically evap cans have a vacuum line connected to them, this is so they can 'regurgitate' the collected fuel into the intake... If you removed the evap and didn't cap off the vacuum line, that might explain the issue.

Good that you found the cause! And good job on the troubleshooting...

I had connected the out line from the motor to the line going back in, bypassing the can. I thought this would effectively be the same as plugging it. Apparently not.

[TominMO]

17-tooth front sprocket on its way. Already have a better chain for it, and a chainbreaker.

Just bought this box for it:
https://www.amazon.com/Yescom-Motorc...318428&sr=8-12

It has a quick release that just leaves the mounting plate on the bike.

[mototech77]

Nice box. I like the mounting tray setup.

When you put on the 17-tooth sprocket the front cover will be a little tricky to get back on. Will help if you can get it up on a stand and rotate the rear wheel a little to rotate the sprocket and chain to where it will clear. There are rear sprockets available for these bikes too if you want to gear up even higher. It is a bit more involved, but was worth the trouble for me.

[TominMO]

Thanks again mt. Helpful info.

Lifan Xpect sprockets available on Amazon below. Do not know about fitment on other brands, but if they are CG motors, I would think they would work.

Front
15 and 17 tooth available: https://www.amazon.com/JT-Sprockets-...78&sr=8-1&th=1
Rear
Lots of options: https://www.amazon.com/JT-Sprockets-...09&sr=8-1&th=1

I suspect any available aftermarket chain is gonna be better than the stock one. Just to be safe, I would not order one that was a lot cheaper than the average. I go with brand names I recognize.

[TominMO]

Sprocket ratios

........15..........17
34....2.27.......2.00
35....2.33.......2.06
36....2.40.......2.12
38....2.53.......2.24
39....2.60.......2.29
40....2.67.......2.35
41....2.73.......2.41
42....2.80.......2.47
43....2.87.......2.53
44....2.93.......2.59
45....3.00.......2.65
46....3.07.......2.71 stock
47....3.13.......2.76
50....3.33.......2.94

[mototech77]

The JTR810 series fit the rear hub. Add a decimal for the tooth number. I installed a JTR810.38 and have the original 15t on the front. Initially I had the 17 and 38 installed but the gearing was too tall for the engine’s power band. I’m pretty happy with the 15/38 (2.533), but I may try to go just slightly taller with a 17/41 or 17/42 down the line.

[TominMO]

Thanks for straightening me out on the rear hub! I amended my two posts, and the one in the Lifan sprocket sticky too.

My rear sprocket is a 46, and if the front is a 15, that gives a pretty low ratio. The 17 should be an improvement for street. Once riding it, I will decide if I want higher; better top end with a slightly higher 1st gear would be great.

[TominMO]

1. How is the durability of the stock sprockets?
2. How long would you expect the JTs to last?