Honda SL125 to Lifan 200cc conversion project

Azmon · 03-25-2018, 10:42 PM

So I restored a '71 Honda SL125 about 5 years ago and have done some multi day trips a few times on it. I ride a BMW R1200RT, but love riding this little honda just as much!! After I checked my compression and found it really low, I decided- what the heck- I might as well increase the displacement, add electronic ignition and get a newer technologically advanced motor- enter the Lifan 163FML 197cc engine..

Worked on this bad boy for several weeks now, due to fabricating a new battery box- the old one wouldn't work with the new motor's carb and air filter configuration. I also decided to completely rewire the bike and add a few relays for stronger headlight (LED) and several other farkles. I also added a KOSO speedo (TNT-01) that's probably meant for cafe racers, but I couldn't resist the mod. I'll need to fabricate a new exhaust- since the old one now won't fit the new engine.

I used a LIFAN wiring harness, which needed a few modifications to fit the bike, and really wasn't able to get a completely accurate wiring diagram. LifanUSA was no help here... When you order an engine, that about all you get- no instructions, no wiring diagram, no printed material whatsoever.... go figure.

Now I've got the wiring almost 90% completed, I have one last thing I'm trying to figure out.

Looks like one of the AC circuits is routed to the headlights. Since I have an LED projector type headlight (harley aftermarket 5.75" bucket and light from Amazon) I don't want AC, power and need to run it on 12V DC.

So I am wondering if I could get a higher powered regulator/rectifier and run the lighting circuit through that and maybe get more amperage in my charging system??? Kinda stumped for now. Any suggestions or help on this will be appreciated. Photos to follow...

humanbeing · 03-25-2018, 11:10 PM

Typical ∅88.6mm stator's ouput is similar to http://www.mxjidian.com/index.php?s=...pinfo/ptid/124
Which r/r is on ur bike? Most modern chinese are 10A rated, some better 1 can handle up to 12A

Skiforce75 · 03-25-2018, 11:14 PM

Very cool project. I have always wanted to take a frame and just start adding parts to make a bike. I know you have more than just the frame, but you get the idea.

**JerryHawk250** · 03-26-2018, 07:51 AM

Nice project. I'll be sure to follow this one.

Skiforce75 · 03-26-2018, 10:00 AM

Quote:

Originally Posted by Azmon

Looks like one of the AC circuits is routed to the headlights. Since I have an LED projector type headlight (harley aftermarket 5.75" bucket and light from Amazon) I don't want AC, power and need to run it on 12V DC.

Couldn't you run the headlights to a switched circuit direct from the battery? Isn't that how cars are wired? Everything runs off the battery and the charging systems only job is to keep the battery charged. Will that not work on a bike?

Mudflap · 03-26-2018, 10:18 AM

I've run led lights off 12v regulated AC with no problem. If DC is needed you could just put a bridge rectifier in circuit. Or maybe get the type rectifier/regulator used on the Roketa 200 which powers all the lights from the battery. I suppose it charges the battery with more amps than the the AC/DC type used on the Lifan 200.

Weldangrind · 03-26-2018, 10:52 AM

Very clean work! I've wanted to do an SL repower for awhile, so I'll definitely be watching this thread.

Azmon · 03-26-2018, 03:56 PM

Skiforce-

That’s actually what I’ve done is wired the headlights directly from the battery via a relay. If you look close at the pic of the battery box with the spaghetti of wires, some of those wires will power the headlights. Hi beam and low beam are on separate relays. My concern is that if an AC lighting circuit was meant to power the headlights, can I reroute the wire(s) to a different beefier regulator and have more charging amps...??

Azmon · 03-26-2018, 08:23 PM

Quote:

Originally Posted by humanbeing

Typical ∅88.6mm stator's ouput is similar to http://www.mxjidian.com/index.php?s=...pinfo/ptid/124
Which r/r is on ur bike? Most modern chinese are 10A rated, some better 1 can handle up to 12A

Not sure the output or model of the R/R, but here's one that looks exactly like it. https://www.ebay.com/itm/12v-Voltage...4383.l4275.c10

wheelbender6 · 03-26-2018, 09:47 PM

I owned an XL125 for several years. I can't wait to see how well your SL runs with the Lifan mill.

humanbeing · 03-27-2018, 12:06 AM

Ur schematic shows the ancient center tap half wave which isn't the industry practice in vertical chonda anymore. To fix = http://mastercircuits.blogspot.com/2...onversion.html or find something as https://item.taobao.com/item.htm?id=22211028618
===
For ref:
Mid 90's (MIJ) CG125M http://www.go-gddq.com/upload/2015-0...0111285802.jpg
Early 00's (MiC) CGR125 https://josemaco.files.wordpress.com...h-62ktjam5.pdf P.328

Azmon · 03-27-2018, 03:24 PM

Humanbeing- I'm actually not sure how the motor itself is set up. This is just the wiring diagram I thought would be the closest to what I would need. I'll add some pics of the main wires coming from the stator- and their relationship with each other continuity-wise. You seem to know these engines and maybe can help me! Dying to finish this project and at least put the electrical part to rest.

Here’s my test on those wires, after disconnecting from the harness-

NONE of the wires connect to ground. (I think maybe the green/white may connect to ground via the wiring harness- will check that one)

G/W----------BLue/W 150 ohms resistance
Y---------------P 1.5 ohms resistance
B/R------------- This wire is somewhat of a mystery. There’s no continuity to any of the other wires, nor ground. BUT… when I put my negative tester probe on it, and the pos probe on the positive battery terminal, and check for voltage, my tester indicates 12.95V…. Tested and retested, and there’s no continuity with the black/red wire and ground! I’m stumped on that one!! According the wire diagram that wire and the blue/white one go directly into the CDI unit...

humanbeing · 03-27-2018, 06:29 PM

A working stator's ohm reading Y-P of course reads like that. Full wave: No continuity btw GROUND of either wire.
G/W seems grounded
b/r is CDI's power source that is tested via ohm/ volt reading as

franque · 03-28-2018, 02:31 PM

Is the bike running yet? If I remember correctly the black/red is the ignition trigger going to the CDI, and blue/white and green/white are power from the motor to the coil.

Azmon · 03-29-2018, 05:19 PM

Yes, the black/red is the trigger and goes straight to the CDI, as does the blue/white. The green/white wire goes to ground. Yellow and Green are the only wires going to the regulator/rectifier. Got that figured out. I GOT SPARK !!!

Working on modifying my exhaust now. It'd fit perfect if there wasn't an oil sight glass in the way. I've never worried about the effort to check a dipstick. I guess some people are in a hurry and would rather use a sight glass.

90 percent of the wiring is now done. I have a few things to button up, but I know exactly how and what I need to do. The hours of studying various wiring diagrams are over!! Some of the switches on the old hondas work differently than the chinese bikes this engine was designed for, ie. the kill switch. The kill switch on the vintage hondas work by connecting and disconnecting power to the coil wire. The lifan's simply ground the coil wire. So I decided to not even wire my kill switch- usually it's a cause for a dead battery anyway...

I hope to fire up the bike on the weekend! Need to drain the factory oil it was shipped with and use Dino oil for the break in period.

03-25-2018, 11:10 PM	#2
humanbeing Join Date: Mar 2008 Posts: 2,436	Typical ∅88.6mm stator's ouput is similar to http://www.mxjidian.com/index.php?s=...pinfo/ptid/124 Which r/r is on ur bike? Most modern chinese are 10A rated, some better 1 can handle up to 12A __________________ Last edited by humanbeing; 03-26-2018 at 02:03 AM.
	0

03-26-2018, 07:51 AM	#4
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,578	Nice project. I'll be sure to follow this one. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	0

03-26-2018, 10:52 AM	#7
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Very clean work! I've wanted to do an SL repower for awhile, so I'll definitely be watching this thread. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	1

03-26-2018, 09:47 PM	#10
wheelbender6 Join Date: May 2015 Location: Houston area Posts: 1,902	I owned an XL125 for several years. I can't wait to see how well your SL runs with the Lifan mill. __________________ "Its not WHAT you ride; its THAT you ride"
	0

03-27-2018, 12:06 AM	#11
humanbeing Join Date: Mar 2008 Posts: 2,436	Ur schematic shows the ancient center tap half wave which isn't the industry practice in vertical chonda anymore. To fix = http://mastercircuits.blogspot.com/2...onversion.html or find something as https://item.taobao.com/item.htm?id=22211028618 === For ref: Mid 90's (MIJ) CG125M http://www.go-gddq.com/upload/2015-0...0111285802.jpg Early 00's (MiC) CGR125 https://josemaco.files.wordpress.com...h-62ktjam5.pdf P.328 __________________ Last edited by humanbeing; 03-27-2018 at 11:58 AM.
	2

03-25-2018, 11:14 PM	#3
Skiforce75 Join Date: Dec 2017 Posts: 87	Very cool project. I have always wanted to take a frame and just start adding parts to make a bike. I know you have more than just the frame, but you get the idea.
	0

03-26-2018, 10:18 AM	#6
Mudflap Join Date: Sep 2014 Posts: 1,889	I've run led lights off 12v regulated AC with no problem. If DC is needed you could just put a bridge rectifier in circuit. Or maybe get the type rectifier/regulator used on the Roketa 200 which powers all the lights from the battery. I suppose it charges the battery with more amps than the the AC/DC type used on the Lifan 200.
	1

03-26-2018, 03:56 PM	#8
Azmon Join Date: Mar 2018 Posts: 28	Skiforce- That’s actually what I’ve done is wired the headlights directly from the battery via a relay. If you look close at the pic of the battery box with the spaghetti of wires, some of those wires will power the headlights. Hi beam and low beam are on separate relays. My concern is that if an AC lighting circuit was meant to power the headlights, can I reroute the wire(s) to a different beefier regulator and have more charging amps...??
	0

03-27-2018, 06:29 PM	#13
humanbeing Join Date: Mar 2008 Posts: 2,436	A working stator's ohm reading Y-P of course reads like that. Full wave: No continuity btw GROUND of either wire. G/W seems grounded b/r is CDI's power source that is tested via ohm/ volt reading as __________________
	2

03-28-2018, 02:31 PM	#14
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Is the bike running yet? If I remember correctly the black/red is the ignition trigger going to the CDI, and blue/white and green/white are power from the motor to the coil.
	0

03-29-2018, 05:19 PM	#15
Azmon Join Date: Mar 2018 Posts: 28	Yes, the black/red is the trigger and goes straight to the CDI, as does the blue/white. The green/white wire goes to ground. Yellow and Green are the only wires going to the regulator/rectifier. Got that figured out. I GOT SPARK !!! Working on modifying my exhaust now. It'd fit perfect if there wasn't an oil sight glass in the way. I've never worried about the effort to check a dipstick. I guess some people are in a hurry and would rather use a sight glass. 90 percent of the wiring is now done. I have a few things to button up, but I know exactly how and what I need to do. The hours of studying various wiring diagrams are over!! Some of the switches on the old hondas work differently than the chinese bikes this engine was designed for, ie. the kill switch. The kill switch on the vintage hondas work by connecting and disconnecting power to the coil wire. The lifan's simply ground the coil wire. So I decided to not even wire my kill switch- usually it's a cause for a dead battery anyway... I hope to fire up the bike on the weekend! Need to drain the factory oil it was shipped with and use Dino oil for the break in period.
	0