Is this really a 138cc

[Trashthumpy]

iv heared that lifan 138cc are actually 127cc does this apply to this kit?
also will it fit a lifan 125? sorry to ask maybe ovious questions but i want to be shoure its good before i buy it. thanx guys
http://cgi.ebay.com.au/Lifan-138cc-...3QQihZ014QQcategoryZ29705QQrdZ1QQcmdZViewItem

 

[binky77]

a link would be good

 

[Bam16]

yeh lol
need a link

 

[Mack]

Basically Lifan was producing two main motors.

The first had a stroke of 54mm and bore of 54mm which makes this motor 124cc. Plenty still in circulation. They are basically very similar spec motors to the Ducar.

The second motor which is the more sought after engine, has a stroke of 55.5mm and bore of 52.4mm and was only a 120cc engine.

Now Lifan has discontinued the first motor but released these new 138's. They are just the second motor above with the 55.5 mm stroke, but fitted with the 54mm piston from the first mentioned engine. They have 138 stamped on the barrel, but are only 127cc!

Now I have heard one person claim that they bought a Lifan with a 56mm bore which would give you 137cc, but this can only have been done by another chinese company either copying the Lifan motor or reboring Lifan cylinders to 56mm ex-factory. I don't know if he really did have a 56mm Lifan motor though.

So, you'll have to email the seller of that kit to find out. I'm sure someone on here has bought one by now so maybe we'll find out that way.

 

[roost]

Basically Lifan was producing two main motors.

The first had a stroke of 54mm and bore of 54mm which makes this motor 124cc. Plenty still in circulation. They are basically very similar spec motors to the Ducar.

The second motor which is the more sought after engine, has a stroke of 55.5mm and bore of 52.4mm and was only a 120cc engine.

Now Lifan has discontinued the first motor but released these new 138's. They are just the second motor above with the 55.5 mm stroke, but fitted with the 54mm piston from the first mentioned engine. They have 138 stamped on the barrel, but are only 127cc!

Now I have heard one person claim that they bought a Lifan with a 56mm bore which would give you 137cc, but this can only have been done by another chinese company either copying the Lifan motor or reboring Lifan cylinders to 56mm ex-factory. I don't know if he really did have a 56mm Lifan motor though.

So, you'll have to email the seller of that kit to find out. I'm sure someone on here has bought one by now so maybe we'll find out that way.

yep mine had a 56mm piston but is was fitted by the seller, but i have since ditched the 56mm low comp piston( steel barrel) and opted for a new barrel (alloy barrel)and a 55.5 high comp piston. You are correct but Lifan now have a 140cc which is 55x59 it will be here very soon. It uses the 120 monster bottom end ( clutch on the main shaft and all up tranny). I will let you know how it goes

 

[Mack]

Not coming from the Lifan factory though, is it?

 

[chiribomb]

What size piston is in this ebay kit from dhz, I have asked but no replies, it uses a 14mm pin, 54x54 use a 13mm I think and 52.4 x 55.5 use a 14mm and 54 x 57.5 use a 13mm, just be sure to check yours.

 

[cranga]

54mm piston, he wont answer back about these, i made the mistake of purchsing one, was exact same piston as the ducar came with. Dodgy

 

[mjc85]

Get a Trailbikes headkit, they should be about $200-$250 or just get a decent piston like the ones roost has and get your barrel re-bored.

The advantage of a headkit is you get an alloy barrel which is much lighter than the cast one.

 

[roost]

Not coming from the Lifan factory though, is it?

yep straight from the Lifan factory , i think they have a steel barrel but that will be ok, if you want to run a alloy barrel you will just have to KLX 110 sleeve it, this will not be my race bike motor just weekend worrier bike. I have had reports from a few people who are running them and they say they absolutely kill the 138. It will be interesting to see what they can be taken out to, i have a 57mm piston on its way will be great if it fits that will make it a 150.55cc, inner rotor , big cam, port and this should make a rocket ship. I will keep you posted on it

 

[cranga]

hell yeah roost, keep us updated, also you should sell a couple of these motors complete!

 

[chiribomb]

check out akunar.com for some really good piston and part deals.
Tbolt in the us has a 140 kit for 160 usd, alloy cylinder piston rings but it is for the 13mm pin rod. 14mm to be out soon.

 

[Madmatt]

You could just build your own like i have. Wiseco make an XR100 oversize piston which is 58mm with 14mm pin. Just resleeve the barrel, there will be no skirt left on the barrel to slide into the cases but it doesnt matter as the piston still has enough engagement in the barrel to properly align itself. The case bore on the Lifan is 59.5mm approx, so you dont have to bore out the cases. You engine will then be a 146.7cc, Dr atv.com is where i originally saw all the info on this big bore.

The big bore by itself is ok, but you need to add a cam to match it. The standard lifan cam in the 120cc is 5.25mm lift. To make good use of the 146cc you would want to run from 6.3 to 7.0mm lift. I have just installed a adaracing crf50 race head cam (6.9mm lift which is the same as the trailbikes racehead cam which is also the same as the z40 cam). i have also lightened the flywheel and oil slinger to help it spin up a bit quicker and added a trailbikes cdi. Ive only had 5mins on the bike, but im now happy with the performance. it pulls really hard, when you wind on the throttle in 2nd without any clutch it still want to lift the front wheel with my 80kg frame on it, if you dump the clutch, you better be sitting right up on the tank or you'll flip it. Big50's in VIC is now selling these and other size kits. cheers.

 

[Madmatt]

Forgot to mention, dont kick start your bike with this kit, my compression is up somewher around the 11 or 12:1 mark. we've cracked 3 cases and kick start gears, so now we are just roll starting them, much safer. youve got to remember, these engines are based on a 50cc version. but for all the troubles, i got to say, the big bore is damn good.

 

[mason1]

Hey guy's if I put a 54mm piston into 120 monster engine, what cc increase will there be.

 

[mason1]

By the way I think it's the same kit at the start of this post.

 

[cranga]

well you will find the answer in macks first post!

 

[Dreadful]

" i have a 57mm piston on its way will be great if it fits that will make it a 150.55cc, inner rotor , big cam, port and this should make a rocket ship. I will keep you posted on it "





Faaaark you'll need a seatbelt lol

 

[mjc85]

Apparently soon there will be one of the 55x59 140cc lifans with an Inner Rotor kit in it and lighter oil slinger available for sale in Oz, not sure about race cam or compression though, but i would love to see how big you can bore it as i might be getting a billet bike with one of these motors in it.

 

[motodad43]

Iam making inquiries into importing this engine, just waiting to hear back. Ill keep you guys posted if everything adds up ill sell some to members on here and flog the rest on ebay, heres the specs
1) YX 140cc big bore engine
2) Ported head with large inlet valve diameter, 23mm / 27mm
3) Ally cylinder
4) High compression piston
5) Inner rotor kit with billet alloy backing plate
6) Balanced crank shaft
7) CDI unit with rev booster, super spark coil pack
8) Large efficient alloy oil cooler
9) Race cam
10) Keihin 26mm carburetor, port matched manifold, round high flow
sponge air filter
11) 4 speed transmission, strengthened gears, all up gears N1234
12) Clutch mounted on main shaft, starts in any gear
13) Billet alloy dress up kit: cam cover, head sink, rocker arm covers
14) Includes kick starter, gear shifter, front sprocket
15) Engine: 4-stroke, oil-cooled, single cylinder, manual clutch, horizontal type
16) Cooler: oversized high efficiency alloy oil cooler
17) Bore (mm): 56
18) Stroke (mm) 57
19) Cylinder capacity (ml): 140.39
20) Net maximum torque: 9.5N.m/5,500
21) Mini fuel consumption: 354g/kWh
22) Valve gap (mm): 0.05 + 0.02
23) Fuel mark: SAEAPI 15W/40-SF
24) Engine oil consumption: 8g/kWh
25) Lubricating system: pressure splash
26) Engine oil capacity: 1.0L
27) Maximum output: 12hp
28) Size: 435 x 285 x 235
29) N.W: 25 + 1kg
30) Transmission type: 4 speed manual, 4 gears up N1234, and clutch on
main shaft
31) Transmission ratio: 1st gear: 3.272 (11/36), 2nd gear: 1.937 (16/31),
3rd gear: 1.350 (20/27), 4th gear: 1.043 (23/24)
I read another post about somone who was going to bring some in, i think it was a similar engine but im not sure sounds like the one being talked about in this post. i dont need any one else to go in the deal so it just depends on the price they give me, judging buy the things ive read i think at the right price they be a sought after simple and total lifan upgrade for any pit bike.
cheers motodad