Picked up the Lifan Xpect

[JFOlivier]

I had a 17 front sprocket and the standard 46 rear, I have just changed the 46 to a 43 with the 17 drive and it just lowers my rpm at cruising at 50 to 55 MPH. I now get an extra 4 MPH at 6000Rpm but still end up with the same top speed as with the 46 rear sprocket at around 68 MPH. 17/46 gets 50 MPH at 6000 and 17/43 about 54 Mph at 6000. I am at about 1200 miles on the clock, adjusted the valves twice at lower mileage and have never had any problems whatsoever and am very happy with the X-Pect,

[mototech77]

Originally Posted by mototech77

I’ve had some conversations with other fellow Lifan Xpect owners about the stalling issues. Adjusting the air bleed screw out some to increase idle speed to about 1900 has helped. However, I have since discovered that at times this adjustment also causes it to stall when cold. The air bleed should be controlled by an IAC valve, but they eliminated this component on the Lifan’s for some reason. Our throttle bodies have a mounting flange for the IAC where the Hawk 250 DLX actually has the part included.

Outside of modifications, the best you can do is to stay on top of maintenance and adjustments.

I ordered an IAC that should fit this throttle body, but it is going to require some machining to fit it properly and open the air circuit, but even then, it doesn’t look like the ECU is provisioned for the connection, so I may also have the challenge of building a circuit to control it.

So, I know this is now an old part of the thread, but I want to make a correction where I misspoke about something. After going through my vacuum lines and wiring today to get a better understanding of functional aspects of my Lifan, I discovered that these do in fact have an IAC (Idle Air Control) valve. Instead of it being mounted on the throttle body flange, they incorporated a separate valve over on the left side of the bike just below the fuel petcock. I don’t mind being wrong when it turns out to be good news.

[TominMO]

Went out to the garage to see if it would start, after four months in an unheated garage and a regular dose of freezing cold temps, including single digits. Turned key, pushed button. To my shock and awe, it fired right up! The battery seemed strong.

Might be some blockage in the fuel injector though. When I would rev it and let it go back down on its own, it would die. Gonna take it for a ride around the block tmw, and if that goes well will put a couple of miles on it.

[Boatguy]

Originally Posted by TominMO

Went out to the garage to see if it would start, after four months in an unheated garage and a regular dose of freezing cold temps, including single digits. Turned key, pushed button. To my shock and awe, it fired right up! The battery seemed strong.

Might be some blockage in the fuel injector though. When I would rev it and let it go back down on its own, it would die. Gonna take it for a ride around the block tmw, and if that goes well will put a couple of miles on it.

That’s just the nature of the xpect. It’s a bike that needs to warm up a minute. That’s what I found. It runs a little lean when it’s freezing cold and just started.

[TominMO]

Originally Posted by Boatguy

That’s just the nature of the xpect. It’s a bike that needs to warm up a minute. That’s what I found. It runs a little lean when it’s freezing cold and just started.

Well ok, but it was near 70 when I started it.

[JFOlivier]

I have found that the idle when cold will shut down unless you work the throttle a little until the engine warms a little, worse the colder it gets. But once you open the throttle and get going you no longer have any problems. I think the mixture in the idling system is too lean somehow, but as it has not troubled me much I have not bothered to dig any deeper.

[Boatguy]

Originally Posted by JFOlivier

I have found that the idle when cold will shut down unless you work the throttle a little until the engine warms a little, worse the colder it gets. But once you open the throttle and get going you no longer have any problems. I think the mixture in the idling system is too lean somehow, but as it has not troubled me much I have not bothered to dig any deeper.

Exactly.

Even at 70 mine does the same.

[TominMO]

Today I installed my two JT sprockets, 17 and 42, to get the street/hwy gearing I wanted. First gear seems about perfect. Also installed a non-oring JT chain and a red Tusk folding shifter. Took it for a kwik spin around the blok to make sure everything was OK.

I was unable to get the front sprocket cover back on, even though I turned the rear wheel to try to finagle it into place. Apparently when installing a 17-tooth, some people don't have to do any surgery on the cover and others do.

Edit: The 15/46 stock sprocket combo gives a ratio of 3.07. The 17/42 gives 2.47, a 20% raise in gearing. Should make cruising at 60 pretty painless, plus a nice bump in MPG.
Edit 2: I blue Loctited every fastener I removed except the rear axle, which I greased (it was dry, big surprise).

[JFOlivier]

It is not easy to get that cover over the 17 tooth sprocket, but if you grind down the edge of the cover where it sort of sticks it is much easier. I ground off about a 1/4" at the top left hand side where the cover fits behind the starter gear, If I remember that starter gear prevents the cover from slotting in once the new sprocket and chain takes up more room under the cover.

[TominMO]

Thanks, I'll give it a try. I have a cheap Chinese bench grinder that comes in handy sometimes.

[KSSK]

I was able to switch to a 17 tooth sprocket by only turning the rear wheel to get the cover on. You could use a Dremel or file or something to grind some clearance in the cover.

[TominMO]

Originally Posted by 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.

In retrospect, I would recommend getting a JT 15 (better steel) and the 36 rear. Gives a 2.40 ratio, and no hassles with getting the cover on/off with the 17 tooth. Basically the same ratio as my 17/42 with 2.47. But I'll keep my sprockets since they are already mounted.

[TominMO]

Got the front sprocket cover back on over the 17-tooth sprocket, with a little grinding on the cover. Had to lightly grind the 90-degree top left edge. Then it went on pretty easily. Touched up the shiny aluminum with a black Sharpie.

With the 17/42 combo, it would only go 50 up a steep hill in 5th. Didn't get a chance to test it at speed on a flat surface. Probably tomorrow. Downhill it did 55. Gearing might be too high for it to rev, I'm thinking. But I'll keep it this way as I like the greater spread in the gearing and the 20% lower RPM in 5th. It now has a good spread in the gears for street riding, so you are not shifting too much, and 5th is now effectively the 6th gear we all want. Even though it's a dualsport, it will only ever see dirt roads, if that.

[TominMO]

Took it out for a test run to see what max speed was. Turned out to be 64 MPH in 5th at about 6500 RPM.. Good enough for short highway trips. I have a friend who is 14 highway miles away, plus some slower back roads. That'll do. I will just cruise at 60 in the right lane.

In town the 17/42 sprockets make the gearing perfect for city streets and dirt roads, where you can just keep going and there is no slow technical stuff to negotiate.

[TominMO]

Was just reading in the Street section about how changing the sprocket(s) changes the reading on the speedo. Didn't consider this. I thought the speed sensor is in the front wheel hub, and so it would be independent of gearing changes. Is this so?

So for now I can only say that with the 17/42 sprockets, it gives an indicated top speed of 64 mph. Now I have to figure out what the correction factor is for these sprockets (if the speed gear is in the tranny). It seemed kinda squirrely at "64", so I suspect it was actually going over 70. But the squirrelyness could be from having the offroad front fender, too.