tuning help

[redemn93]

hi guys. i have a lifan 200 in a 200x. knock off mikuni 30mm carb, stock 200x exhaust/muffler without flame arrestor and UNI filter is stock box. i just got it running and went for a ride around the block. i did a plug chop as i approached my driveway with a brand new plug in the motor. pretty lean as you can see in the pics. it didnt seem to run too bad but i have limited riding experience. this was just a fun little project for me to do and ive always liked 3 wheelers.

it idles well.
slowly reving in neutral seems ok.
quick stabs in neutral will bog
if cruising and suddenly going wide open, itll bog for 1/2 a sec and take off.

i want to say the main jet in this carb is a 95 but i havent removed it to verify. i have not really messed with the idle mixture screw. hard to reach without burning myself. the plug chop is after a ride around the block (almost a mile) and at the top of 2nd gear.

i have videos of the idles and reving in neutral but having trouble uploading them.

[Jmoozy27]

It looks hot and slightly rich at idle. I would buy a few main jets and switch them out and see if the bog goes away. 95 main sound pretty small. Maybe try a 110 main with a 40 pilot and see where that gets you.

[DohcBikes]

95 is way lean. 30mm will likely prove too large a carb to run. I'm with jmoozy, put in a 110 main and see what happens. Kudos for actually knowing what a plug chop is and how to do one. I've had to laugh and pass on several posts regarding this lately. Don't try other stuff, order larger mains, several sizes, there's no way around it.

[redemn93]

understood. thanks guys. i read up before doing this, trying to establish at least a real basic knowledge and not sound like an idiot. lol.

also, the chop was with the needle clip all the way down (richest point) as i knew it was lean but wanted to ride and see how it felt. get an idea for whats needed.

what should i do with the idle? any recommendations on setting the air screw?

to clarify on the carb size, its only 30mm at the rear of the throat. the center, where the slide is, is smaller. ill break out the calipers when i remove the carb tonight if that makes a difference to you guys. im using what i think is the stock 200x intake manifold. ill get a picture tonight and you guys verify. thanks again.

[redemn93]

how do you guys feel about the "OE Equivalent" jets?

http://jetsrus.com/a_jets_by_carburetor_type/jets_mikuni_4-042_main_Hex.htm

[DohcBikes]

understood. thanks guys. i read up before doing this, trying to establish at least a real basic knowledge and not sound like an idiot. lol.

also, the chop was with the needle clip all the way down (richest point) as i knew it was lean but wanted to ride and see how it felt. get an idea for whats needed.

what should i do with the idle? any recommendations on setting the air screw?

to clarify on the carb size, its only 30mm at the rear of the throat. the center, where the slide is, is smaller. ill break out the calipers when i remove the carb tonight if that makes a difference to you guys. im using what i think is the stock 200x intake manifold. ill get a picture tonight and you guys verify. thanks again.

It's not a priority to measure the carb, what you have is what you have so you might as well attempt to tune it. But, are you sure it's a mikuni copy? Mikuni carbs don't normally bolt right up to 200x intakes. The only reason i ask is because theres no need to order mikuni jets if what you have is a kei hin copy. Post a pic of your carb, please.

See if you can find the model number of your engine, it's likely stamped down by the shifter. An example would be 163FML. It'll help me to point you in the right direction on jetting. Not long ago we had a guy here that thought he had a lifan 200 but what he really had was a 145cc. They look the same externally.

Return your clip position to the middle setting for the time being. As mentioned, post a pic of your carb. Yes if it's a mikuni it might have an air screw, but i'm hesitant to give advice on an idle mix screw until we know exactly which carb you have. A model number is also welcome.

[redemn93]

actually, i'm pretty sure it is a 163FML. i remember laughing at the FML cause that how id felt lately.

ebay auction said mikuni 30mm. but you never know with the chinese i guess. there is an air mixture screw on it. messed with it a little didn't really see much change. but like i said, hard to reach running and not burn myself. even with gloves on. i have kinda wide hands too which doesnt help. i'll remove the carb and open it tonight if i get the time. i wasn't going to order anything until i could visually verify what i had.

being that lean, will it pull harder up top if i get it dialed in well enough?

[DohcBikes]

actually, i'm pretty sure it is a 163FML. i remember laughing at the FML cause that how id felt lately.

ebay auction said mikuni 30mm. but you never know with the chinese i guess. there is an air mixture screw on it. messed with it a little didn't really see much change. but like i said, hard to reach running and not burn myself. even with gloves on. i have kinda wide hands too which doesnt help. i'll remove the carb and open it tonight if i get the time. i wasn't going to order anything until i could visually verify what i had.

being that lean, will it pull harder up top if i get it dialed in well enough?Again, post a picture of your carb from several angles please. If you are burning your hands tuning, you likely have a fuel screw, not an air screw. Sounds a lot like you have a copy of the kei hin design pz30 perhaps.

The 163FML is a great engine. A 110 main and a 38 or 40 pilot should be in the ballpark. Then you can tune the idle mix and the needle.

[redemn93]

Ah ok. Screw is on the rear (manifold side) of the carb. I'll get pics tonight. Thanks.

Sent from my SAMSUNG-SM-G900A using Tapatalk

[DohcBikes]

Then it is a fuel screw. Start by soft seating, then go 2 turns out. Post up when you have the new main in, and we can help you dial in the off idle throttle response with the fuel screw. You're welcome.

For others referencing this thread, a mix screw on the intake side of the carb is typically an air screw; in for richer idle mix, out for leaner idle mix... A mix screw on the engine side of the carb is typically a fuel screw; out for richer, in for leaner.

[RubberSalt]

https://www.amazon.com/Pit-Posse-PP2751-Motorcycle-Carburetor/dp/B005SUU2HS/ref=sr_1_sc_3?ie=UTF8&qid=1469456335&sr=8-3-spell&keywords=carburator+Screw+Adjusting+Tool

I've got a similar tool from MAC. It's my best friend in 4 stroke tuning.

I'm with DOHC on this. It's probably a Pz30.

The only way to avoid buying a bunch of jets is to have a bunch of micro drill bits. What I've done for ever now is this:

Take a spare jet and drill it out, one size up at a time. When it runs the best, take that bit and go to the store and find the jet that fits best. If you over drill it, you can solder it back up and redrill.

233621

Mikuni make's life easy for drilling things out. The chart comes from here: http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm

[redemn93]

thanks. i have gauge pins small enough at work to check ID but no micro bits. think i found some on amazon that will arrive tomorrow. if i drill the jet and it runs fine and plug looks right, is there really a need to buy a new jet after?

i know you guys aren't local to me but what typical stores carry micro bits?

[redemn93]

Ok. Got the carb apart. 100 main, 20 pilot (sound right?), fuel screw was 4 turns out. Set it to 2 out. Float was nice and level. Guessing it's a 26 by the pn.

http://uploads.tapatalk-cdn.com/20160726/be11f1dcc48c26017d2663d7e899150f.jpg
http://uploads.tapatalk-cdn.com/20160726/8b17b37a24c87ae1a52e2eef4255b6eb.jpg
http://uploads.tapatalk-cdn.com/20160726/cd6ae00ee299fd596d6a885ab9477317.jpg
http://uploads.tapatalk-cdn.com/20160726/20f469af846f77f5246cd56354847e32.jpg
http://uploads.tapatalk-cdn.com/20160726/b64fca1bca3ee9056cff03e30da4243e.jpg

Sent from my SAMSUNG-SM-G900A using Tapatalk

[redemn93]

http://uploads.tapatalk-cdn.com/20160726/7ada7595b6d8e714c315c2e7139af737.jpg
http://uploads.tapatalk-cdn.com/20160726/7dd57a113d4b02f847cae36137dacd88.jpg

Sent from my SAMSUNG-SM-G900A using Tapatalk

[oscarmayer]

your running lean on the mid and top, and rich at idle. idle jet needs to be moved down 1 size. main jet needs to be 2 sizes bigger needle should be 1 from the bottom and you need to adjust the mixture screw.

[DohcBikes]

Hmmm. From what I can tell that is a vm26 copy. So realistically your jetting should be close. I don't have good luck with tuning mikuni carbs on these engines, probably because I don't waste my time since I know more about kei hins. Personally, I'd just buy a pz30 for $14 http://www.ebay.com/itm/30mm-Carburetor-PZ30-Carb-200cc-250cc-Cable-Choke-Dirt-Bike-ATV-Quad-Taotao-Sun-/152156596462?hash=item236d3d68ee:g:k2cAAOSw2GlXFlW M&vxp=mtr, but others here might have some input for jetting on your mikuni copy. I just don't have the patience for drawn out jetting threads and from my experience, that's what this will become with that carb.

You could post the same pic of a plug on two different days here and get 2 different answers from the same person. I've seen it happen. Plug reading is not like it used to be, the fuel formulas are different and they dont leave the same signs they used to.

Anyone that tries to tell you that they can determine how the bike is running at idle, midrange, and high rpm by reading one plug chop is full of it.

[oscarmayer]

once he gets the jetting set, he is going to have a flat spot in the middle where the needle transitions to the main about 1/3 throttle. the reason is the 30mm carb flows too much air for a non-stroked non-hi performance build motor. a 26mm would have better suited your needs and been easier to tune. Stock is I believe 24mm. 28 should have been max w/o a stroked kit.
anyway good luck. I have done a lot of testing on carb sizes with these motors. 30 idles great, you blip the throttle and it's flat, slowly rev to mid then hammer it and you better hang on. it's pretty much a race only setup for that motor.

[redemn93]

Does the pic with the part number suggest it's a 26? Only the opening is 30mm.

Sent from my SAMSUNG-SM-G900A using Tapatalk

[DohcBikes]

Lol. I've done over a thousand tuning runs on a dyno, countless in the field, and have installed and tuned more Lifan engines than probably anyone here including several 163fmls. My suggestions have been made. Have fun with that mikuni guys.

[redemn93]

Hey guys, let's not start a pissing match about who is better. I'm just trying to get my trailprotrailprotrailprotrailpro running right.

Will the pz30 run right out of the box or need jetting?

Sent from my SAMSUNG-SM-G900A using Tapatalk

[DohcBikes]

:beer:beer:beer

[redemn93]

Thanks

Sent from my SAMSUNG-SM-G900A using Tapatalk

[DohcBikes]

You're welcome. I already told you what you need to know. Like you said, I don't have time for a pissing match over a $14 carburetor.

[redemn93]

Right. And I asked a question about the carb you suggested. I didn't argue. You're pissy with me cause someone else argued. Who knows, you both might be right. Have a great day.

Sent from my SAMSUNG-SM-G900A using Tapatalk

[DohcBikes]

You're pissy with me Not at at all. The carb model and jetting has been suggested in this thread. No tuner worth his salt is going to tell you that "X" jetting will undoubtedly be what your engine needs. That's why it's called tuning. Have a great day as well, hope to see a post regarding your progress.

[83ATC185]

Yeah find a 200x carb, bolt it up, adjust the mix and idle and enjoy... I have a street bike with that motor in it and that's what i did when the float stuck in the chinese one. I'm surely no tuning expert, and 10 minutes later i had it running with no problems....

BTW how hard is it to fit the 163FML w/starter in a 200x frame? A project I've been wanting to do for a year now because Chinese motorcycles are scary baaaadd...

[redemn93]

i found some bits to drill the main on this one. just cause i have it, ill try that. the mixture screw was set way rich. ill lean that out, and go from there. i have what i think is a keihin torn down sitting in a box here. i need a new fuel bowl oring for it and maybe another few small parts. i just dont see the benefit of buying parts for it when a new one is a couple bucks more. if i have to, ill try like Dohc said.


motor went is real easy. bolted right in except the cross bar on he bottom of the engine cradle. i cut it out and welded a new piece probably 1-1.5" forward. lots of info on the swap if you search for it.

pic is before i clean it up.

[DohcBikes]

That crossmember can also be persuaded with a 2lb hammer. :)

Also recently learned that the stock 200x clutch cover fits some of the lifans, which makes the rear brake setup much easier, avoiding fabrication altogether!

[redemn93]

That I will have to remember when I get there. Down shifting and front brake slows it down enough for now. Rear brake will be this winter.

Sent from my SAMSUNG-SM-G900A using Tapatalk

[redemn93]

I can say that I hate the shifter. Needs to move out about an inch. Maybe a hair less. I've used all the adjustment though and it's rusted onto the shaft. Will have to use a puller on it.

Is there a shifter you like on this frame/motor combo?

Sent from my SAMSUNG-SM-G900A using Tapatalk