Lifan 150 performance mods

[mikkh]

I bought myself partially complete LIFAN 150 with missing electrics system, carb, oil cooler, clutch and clutch bracket, camshaft and intake valve.
So I would like to know what works for this engine and what doesnt.
I am planning to use IRK or lifan ORK, OKO 28, 32mm exhaust, z40 yx 140 (which bearing I should replace for that with?) with stiffened springs, 4 plate yx 140 clutch (can´t find 5 plate clutch, i have two 5 plate clutch hubs if I could just put in one extra plate.
Which oil cooler I should use
billet
or finned

By the way does anybody know where I could buy a lifan 150 15mm pin 59mm stroke crankshaft in Europe?

If I am going to build that kind of engine I would need to do some suspension work too. So what forks and shocks would be good for CRF 70 size pitbike frame?
The originals were junk and they broke within a month. The internals were quite lacking I should say compared to my KX 250 :lol: .

 

[my67xr]

Those 2x cooler's are pretty much the same, just basic but should keep the 150 cool.
But these are the better style cooler




Carby wise i tried an OKO 28mm on mine but it lost a lot off the bottom end, i replaced it with an OKO 26mm and it brought it to life in all rev range's.
32mm exhaust is good for the 150
I would use an ORC off the Lifan 150 if you can get it, those IRK are pretty unreliable unless you spend big $$ on a Takegawa or Kitaco Inner Rotor kit.

The Z40 cam should work well with the big valve head, give it a clean up though the port's with a die grinder if you have one.
Upgraded spring are a must too.


The only problem's to watch out for with a Lifan 150 is the r/h case isn't that strong.
If you get a bit of kick back when trying to start it they are prone to crack the case around the gearbox mainshaft bearing.
Look at about 4 o'clock around the bearing on your's, you'll see how thin they are there

What is wrong with your crank ?

 

[mikkh]

I bought the engine from a mechanic I know. The crank went boom. The pin ripped thru con rod and ruined cylinder. He took apart the engine and inspected it and started ordering parts. He game me new cylinder and crank too, but the crank had been sitting for a while and has tiny up and down play in it. The old crank is still tight.

Is this better?

I founded a big oil cooler from a motorcycle or something. Is it too big for the lifan oil pump?

 

[mikkh]

Would like to know how big volume oil cooler I could use?
The 4 plate clutch basket should work basically? Does anybody have some info about the crank?