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_carbure...2_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.

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[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-PP2...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.



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







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[redemn93]

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[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.