Air filter replacement
 

I just received a new air filter courtesy of E-Bay. Its the same model used by ImEazy as seen here

I'll be installing and documenting it this weekend. Including before/after pics and spark plug analysis.

Even if no performance benefit is derived at least I won't have to take off that flimsy airbox cover anymore. Each time I open it I figure this will be the time I crossthread the screw holes.

Metal screws into a plastic housing, yeah that's gonna last.....

How often should an air filter be checked or changed?

depends on what type of filter you have and type of riding you do. if you ride a lot of trails and dirt roads and have a sponge type, clean it with dish soap and water at every other oil change and squeeze in a few drops of oil after it dries. You'll probably have to replace it at some point within 2000 miles due to the material getting weak or breaking down. I ride mostly on the street and cleaned mine at 1500 miles, wasn't that bad. The aftermarket types I'm not so sure about, I do know that they appear to get dirtier due to not being enclosed in a factory breather box, I would pay more attention to this type of filter.

An intersting development....

I replaced the air filter with the aftermarket. But before I took me inaugural ride I checked the plug. Colour was perfect. That nice deep tan/leather colour we all crave. Crap. This means the air/fuel mix was perfect and I probably just messed it up. Went to start the bike an sure enough it would only start/idle on full choke.

I guess I'll have to put the old filter back for now. I will probably experiment with upping the main jet a notch or two once I find out what Japanese carb is compatible. I wonder if re-setting the c-clip on the needle jet would help?

Imeazy,

You used the same air filter, did you encounter any problems?

frostbite - I never ran my bike with the stock airbox on it, so I don't
know how it would've ran. I started with the pod filter and the muffler
unrestricted. I did have to adjust everything quite a bit before getting
it to idle properly. it now runs just fine. I went for a little ride this
evening. Ran fine. Checked the plug, looks fine. I think I'm about as
close as I can get without rejetting. I have thought about going one
to two sizes up on the main jet. I need to find a place to buy the jets.

I dropped the c-clip on the needle jet to its lowest position (ie. more fuel). The bike started and idled fine with the new filter. Actually it started with much less choke than before the new filter.

It sounded 'different', probably because the stock airbox/filter muffled some engine noise, plus I was test driving with the side panels off. Plug colour was very good, a touch lighter than before but not much.

I'm gonna drive it a few days like this and see how it works and what, if any, the impact is on fuel economy.

I seem to recall someone in this forum has an ATC 200X. They used the same engine as the XR 200 for which the 163FML is a drop in replacement.
I believe the 200X used a Keihin carburetor. It would be an interesting exercise to compare the main jet from the 200X to the main from the 163FML engine. If they are indeed interchangeable we would have a source of main jets for these bikes.

I replaced the carb on my 200x over 20 years ago with a 28mm mikuni flatslide type, the stock carb was 26mm keihin with a 108 main jet. Partsfish.com listed 2 main jets, a 110 and 108. Does anyone know the jet size on the china bikes? It should be stamped on the jets head. wish I still had the old carb to compare. It wouldn't hurt anything to take the jet out and bring it to a honda dealer or mechanic just to compare, I'm sure they've got some laying around. It would be nice to know if the gaskets will interchange also, you can only take the bowl off so many times before the gasket goes to sh--.

I'm still looking for a local shop that will let me match up the jets I have with new ones. I want to put the 30mm carb I got off ebay on it but I have to fabricate a plate for the intake to make it seal properly. The 28mm carb that is on the bike has a 98 main jet in it. I think if I was to goto a 99 or 100 main jet it would make everything better. I put together a quick tutorial on rejetting a GY carb if you care to check it out.

http://www.eazys.net/GY200/Carb/carbjets.html

Great tutorial, thanks. I am not planning to rejet mine, but just to know where all the stuff is really helps.

Thanks! I have wanted to see where the jets were and what was involved. I don't think I will tackle it right now but down the road it might be on the project list.

The performance was awful in the low end so I replaced the old air filter assembly (BTW really, really poor quality construction...) but left the c-clip changes. Performance is back and it starts with much less choke than before.

I still want to try a main jet upgrade. Maybe this long weekend ( Canada Day here).

Which air filter are you using? The oem box or the cone replacement filter?

I have an OE Honda XR200 carb and the OE Lifan carb out in the shop. I have compared them by outside appearance, I would say they are 99% equal.

I can drop the bowls and check the jets, if anyone is still interested.

For the love of God man, YES!! :lol:

If I knew which jets were compatible I could up the main a notch and put my aftermarket filter back on. Also, since the carb appears compatible with an XR200 (year?) perhaps I can get a K&N.

Cone.

http://www.chinariders.net/gallery2/...serialNumber=2

what size filter is that, how big an opening?

That filter is way too small for a 200. Check into a Uni pod filter. Too small a filter will make the bike run rich and allow dirt to be pulled through the filter and into the motor.

You can put the pod into your airbox rather easily. On my kids conversion bike, a CR80 frame with an XR80 motor, I took a piece of clear vinyl hose a little smaller than the carb spigot, heated the hose and forced it onto the spigot, then let it cool. Cut a hole in the airbox, stuck the hose in and sealed the hole with black RTV. Mounted the pod on the vinyl hose inside the airbox.

I will have a look at the 2 carbs after I cool off from the day's work, and give my opinion on the jet's compatability.

[quote="ImEazy"]Thanks for the writeup and pics. Very informative for the mechanically retarded like myself.

The pilot, or idle jet appears to be exactly the same between my Lifan Carb and the OE Honda carb [Keihin].

The Lifan carb appears to use what I used to call "flat-top" jets. These look just like a small flat blade screw, only with a hole in the center. Honda used this style jet back in the '70s.

The bowls are slightly different as well. The Keihin bowl is deeper, and the jet is mounted on an extension, I would say this is to keep the jet in the fuel in extreme conditions.

Based on appearances, you could possibly buy the Keihin jet holder and deeper bowl, then convert to late model Keihin jets.

FYI, my Keihin carb is from a '93 XR200.

Here is a good place to shop for jets, after doing your homework

www.sudco.com

I would like to get one of these air filters to replace the stock filter and air box on my Lifan 200GY-5. (Somebody posted this link previously, forgot who)

http://www.motocrossuniversity.com/p...ategory_id=382
or
http://www.motocrossuniversity.com/p...ategory_id=382

I haven't had time to take it apart and measure the outside diameter of the air intake side of the carb. Frankly, I am being lazy, I don't want to have to do it now and again when I get the air filter. :-)

Does anybody know the diameter so that I can order the right one?
Thanks!

dlunt - I'm pretty sure it was 39mm the carb is 28mm.
I just went to the garage and looked at the 30mm carb
I have and the filter was 42mm. Hope this helps...

When I bought the filter for the 30mm carb I measured
for it wrong and ended up with a 48mm filter that I won't
use. If anyone wants it or has use for it? I'll send it to
you for shipping. Just let me know.

Thanks ImEazy
I had time yesterday to pull stuff apart and verify.
42 millimeters = 1.65 inches
I measured just under 1.75 inches for the outside diameter.
You were on the money size wise.

It also looked like the 6' one would fit easily in the space.
So I orderd on of the 1 3/4" X 6" UNI Flex Core Sock Filters.
http://shop.thumpertalk.com/catalogs...ault.asp?p=512

I left the cover off of my current air filter box. Now I have a little bit of a stutter in the powerband. I imagine once I get the free flowing UNI pod on there that I am going to have to fiddle with the mixture setting a little until I get it right.

Glad I could help. Yours must have come with a 30mm carb then. Mine came with a 28mm.

LeFan 200cc carb jetting
 

Anyone know where I can find a smaller main jet for the LF200 GY-5? I live and ride at 9000 feet elevation. Thanks, ZZ

LF200 GY-5 carb jetting for altitude
 

OK: I found what I was looking for...carb main jets.

For my altitude (9000 ft.) and the nominal air temperature we typically ride in, I've ordered some smaller main jets for my daughter's bike. The stock jet in my LF200 GY-5 was a 98. I'll calculate that I'll need either an 88 or 92. Ordered both and a couple more sizes from ww.sudco.com (minimum order is 4 jets).

The carb main jet is from a Keihin Carb. Use 99101-393-xxx for Honda VB, VD and VE series carbs: 6mm round head diameter and 8mm overall length.

Good luck and hope this helps.

PS I also dropped (leaned) my needle one notch. I'm assuming that helps although I did not notice any part throttle (< WOT) problems. I thought I would also order a smaller pilot jet but could not find the type of jet. Since I've not had part throttle issues, I'll probably jet focus on the main jet for now.

Installed new Uni Flex Core Sock air filter on Lifan GY-5. 6" one. Fits good.
http://shop.thumpertalk.com/catalogs...ault.asp?p=512
I can definitly feel a good difference when I roll into the throttle. Top of the rpm's breathes much better.

But if I do full hard twist of the throttle it just pauses before it goes.
I think I need to do the c-clip in the carb down one more setting.

If that doesen't do it then I was wondering if there is there a carb adjustment screw somewhere? I know which one is the idle adjustment.
But I noticed a knurled and slotted screw at the front bottom of the carb.
It has an ink mark like you usually see on carbs that can be adjusted.

Or is there a cover that needs removed to get to an adjustment screw?
A couple of my Jap bikes had these, but I never had to touch them.

dlunt,
Seems like you have a good plan here. I am interested in doing the same thing to my new 2006 roketa RKM-E5. It kinda seems like a hassle though, especially seeing as I just got it running perfrectly. 93 octane gas and some adjustment with the idle screw worked the kinks out. Let me know how changing the air filter works for you and i'll probably do the same to my E5.

It is some work and trial and error. I really like the acceleration improvement.
See this thread:
http://www.chinariders.net/modules.p...iewtopic&t=380

To add to that I have actually backed out the fuel screw almost 2 turns from the stock setting. I think larger jets would help even more. I am waiting for someone to successfully do this, then maybe I will give it a try next summer.

where'd imeazy get that air filter?

where do I get one?