Lifan 125cc on CT70

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deanm

New Member
Looking at picking up this engine on ebay... emailed and they said "it should fit ct70, but for modifications check with a professional"... it doesn't come with clutch cable, lever, or wiring harness.... is this a good deal? Or is there a better one out there for the $'s? do you need to change the wiring harness going to 12v? You guys are the pros
http://cgi.ebay.com/ebaymotors/125c...9QQihZ004QQcategoryZ35595QQrdZ1QQcmdZViewItem
 
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6

69ST

Well-Known Member
Not much to go by in terms of determining quality. Getting prices down to this level takes serious cost cutting and who knows where those cuts were made. I wouldn't expect much from a new engine that retails for less than the parts needed to do a complete overhaul on a stocker.

That listing is vague and confusing. What, exactly, makes this a "racing engine"? "Oil cooled":confused: All of these engines are air and oil-cooled, even vintage Hondas; no distinction in that claim. The word "compatible" is overused and that raises the question "compatible with what?" 7lbs-ft of torque at 5000rpm and peak hp rated at 7500rpm indicates that torque falls-off above 5k. It would have to rise above 5k as even 7lbs-ft @ 7500rpm wouldn't equal "12+"hp. It's either being sold by someone with a weak command of English, doesn't know the product or is deliberately misleading. Could be a combo of those. Buyer beware:confused:
 
clubford00

clubford00

Member
All of the above being said, one other aspect of "Compatible" to consider is that they might mean something as simple as the fit! compatible with the honda frame. One more thing to think about. Also One thing racer brings up is the dollar to value idea. You get what you pay for. It might make good power and everything might work great, at first ! but whats it going to be like in 3 months of riding? My opinion is get yourself an original honda engine and put a big bore kit on it. That way you know it will be running years down the road. Just my 2 C. Dean
 
Dan_Lorenze

Dan_Lorenze

Member
Hey Dean, I've had my Lifan 120 for quite a while, I also bought it from the same guy "Legendmoto", they're actually considered 120cc's (52.4 X 55.5). I've put on over 1200 miles of nothing short of abuse on this little engine,pure fourth gear street abuse, the stock engine will take your CT over 60mph with proper gearing. I went into it thinking I'll just run it over the summer and junk it when I wore out, the motor never quit running stong.. To me, the description in the ebay auction is pretty straight forward, he tells you exactly what you get. The reason for the "it should fit" comment is because on ebay you're dealing with a lot of variables with different bikes and from what I get from it he's just covering his bases.. I do however think that his HP rating is a bit optimistic, nine or ten HP is probably more like it..

The engine fits right into the CT70 frame, it's two bolts. You're on your own when it comes to your controls and wiring the 12v engine with it's CDI into the 6v system found on the early CTs.. Dratv.com sells wiring kits that will help in the process of hooking up all the electrical but I've found that buying an aftermarket Chinese wiring harness will make your conversion much easier.. You'll have to change out the 6v bulbs to the 12v bulbs which are available.

Parts are also pretty easy to get for these Lifans.. Over the last month I've managed to build my Lifan to a 145cc along with some porting,Crower race cam, 26mm carb and a valve job.. The power is very nice and I'm having a lot of fun with it..

Bottom line... You get a lot for 300 bucks.....

good luck

Dan
 
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PastaP

New Member
Hey Dan, thanks for the info. This thread is of great interest to me seeing as I have 2 CT70s & 1 ST90. I just figure that an upgrade in cc's is inevitable - it's just a matter of time. I have a few questions though:
1. How long does the total conversion take (w/ a bolt on Lifan)?
2. Why does the wiring harness have to be changed? I know that the Lifan is 12v, but the original 6v wiring harness should be OK for 12v too no?
3. What's the most difficult part of the conversion?
4. Where did you put the CDI box and other additional electronics?
5. What gearing changes did you have to make to the front and rear sprocket?

Thanks!

Paul
 
Dan_Lorenze

Dan_Lorenze

Member
Hey Paul, as far as time goes it should really only take you a day or two to get it mounted up, it might take you more time to sort out the wiring.The only reason why I suggested a new knockoff harness is because it's already wired for the 12v system with wires for the voltage regulator and CDI box. The hardest part was getting all the lights to work. It takes some time.The best gearing combo I've found was 16/35. I mounted the CDI box between the seat latch and battery while I mounted the voltage regulator down below inside the frame
 
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deanm

New Member
wow!! Lots of great replies... I have 2 ct70's so I think I will start with a big bore, and see how that works. It was only $90 for the 88cc and I didn't have to mess with wiring etc... should be able to fire it up tomorow and see. Depending on that, I'll decide how to proceed with the other ct. Got to say though sure leaning toward the lifan for the other one now....:scooter:
 
D

deanm

New Member
Its been a while and I thought I would give an update. The 1969 ct70 I did the 88cc, was so easy, but still not great torque, tops at 35~40? downhill LOL. Only thing left is valves...
The HK1 ct70 I did the Lifan 125cc, is nothing short of great! Torque to spare, over 55 easy, and it gets there quick. The assembly was pretty easy with some adjustments needed on the footpegs and muffler (it is a bigger engine of course!!) The wiring was the major headache, but finally converted nicely to 12v successfully. (I became a wire diagram junky)--and found most of the chinese cables wire colors do not match the lifan wire colors... so it was "go color blind" and pay attention to the schematics.
All in all the Lifan is quick and fun... but my heart is in the original ct70 1969 stock (with just the 88cc change).
I will post some pics soon, but this is West Michigan and April and we are getting a major snow storm! Yuk
 
6

69ST

Well-Known Member
You're never going to get much torque with 88cc compared to 120cc. There's no replacement for displacement, at least where torque is concerned. However, there's another school of thought that says the only substitute for cubic inches is rectangular dollars. It is possible to get 60mph from 88cc but the engine has to be scienced-out as a high-revving, horsepower, system. 9hp from roughly 90cc is possible, just not as easily as it is with more displacement.

As for the weather we're having, feel free to keep the snow on the sunset side of the state. It's merely cold, wet & windy here on the sunrise side. Since we no longer seem to get indian summer in the fall, this must be indian winter...or something:confused:
 
D

deanm

New Member
racerx... question... do you think replacing the valves would help? The head is from '69... replace it all? Literally have done everything else from the 88cc, cam chain, points, carb, chain, sprockets, etc... I don't expect the torque of the 125cc, but thought I would see 40mph (my 50cc goes 35)
 
6

69ST

Well-Known Member
All else being equal, I'd expect to see 45mph from a basic 88cc kit. That assumes that you've got the carb dialed-in, your exhaust isn't choked-off and that you at least lapped the valves & checked for proper sealing.

Something's amiss if the bike won't break into the 40s. A stock 3-speed with a healthy motor should top 40mph. I'd expect an extra 17cc displacement to be good for 5-7mph, minimum.

If you didn't go through the head, tsk, tsk:rolleyes: Time to do so now. I've seen exhaust ports heavily clogged with carbon buildup and nearly every CT70 motor I've rebuilt has had a worn intake valve, as-received. Between bleeding off compression into the intake and exhaust port restriction an engine would run as if there were a rag stuffed in the carb and the parking brake left on. New valves & springs won't even set you back half a C-note. Cleaning the carbon is a freebie. If you can't do the valve job yourself, a legit shop shouldn't charge more than about $50 if you bring them the head.

Make sure that the air filter is clean and unobstructed. The stock airbox is pretty restrictive, at best. Also make sure that the carb is correctly jetted. This size bore-up kit usually requires a main jet that's 2 sizes larger than stock. You might want to consider adding an 18mm carb & K&N (or similar open element design) air filter. Adding a more performance-oriented cam would help, too. Throw in some port work on top of the other changes and you should see the high side of 50mph. A performance head would give you even more, but of the heads Honda used on their 72cc motors, the CT70 versions came with some of the largest stock valves. In good shape, the stocker's not a bad piece.
 
cap279

cap279

Member
Lifan Parts?

Dan_Lorenze said:
Hey Dean, I've had my Lifan 120 for quite a while, I also bought it from the same guy "Legendmoto", they're actually considered 120cc's (52.4 X 55.5). I've put on over 1200 miles of nothing short of abuse on this little engine,pure fourth gear street abuse, the stock engine will take your CT over 60mph with proper gearing. I went into it thinking I'll just run it over the summer and junk it when I wore out, the motor never quit running stong.. To me, the description in the ebay auction is pretty straight forward, he tells you exactly what you get. The reason for the "it should fit" comment is because on ebay you're dealing with a lot of variables with different bikes and from what I get from it he's just covering his bases.. I do however think that his HP rating is a bit optimistic, nine or ten HP is probably more like it..

The engine fits right into the CT70 frame, it's two bolts. You're on your own when it comes to your controls and wiring the 12v engine with it's CDI into the 6v system found on the early CTs.. Dratv.com sells wiring kits that will help in the process of hooking up all the electrical but I've found that buying an aftermarket Chinese wiring harness will make your conversion much easier.. You'll have to change out the 6v bulbs to the 12v bulbs which are available.

Parts are also pretty easy to get for these Lifans.. Over the last month I've managed to build my Lifan to a 145cc along with some porting,Crower race cam, 26mm carb and a valve job.. The power is very nice and I'm having a lot of fun with it..

Bottom line... You get a lot for 300 bucks.....

good luck

Dan
Click to expand...


Parts are easy to get? I am in the process of locating clutch parts for my Lifan 125cc, and have not received any replies yet.
Please help.
 
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