Mikkh's WPB 125 CRF 70 framed build

[my67xr]

What reading did you get off the stator ?

Kick back sound's like the timing is too advanced ?

Dying when you blip the throttle could be a partly blocked pilot circuit,either before the mixture screw, in the port's between the air filter side of the carby to the tiny port where the fuel/aor flow's into the bore of the carby or blocked pilot jet


With the pick up coil hitting the tab on the flywheel, loosen the 2x screw's that hold it to the backing plate and move the coil away from the pick up then retighten the screw's.
If you cant get it to move enough, the take the pick up coil off the stator plate and file the hole's out to allow for the adjustment.


Here's the ground flywheel tab mod

Have you had a timing light on it to see what advance it has at idle, or your total advance ?

 

[mikkh]

I haven´t got a timing light. The reading was about 11-12 ohms (don´t remember correctly, will have to check). Tried different carbs with same results. There were marks on the pick up that it had mated with the stator before. I already had set the gap. The engine ran perfectly with the 1kg magneto setup I had laying around. If the engine warms up it went a little better (managed to hit the limiter on couple of occasions).

 

[my67xr]

The stator should give you about 10.5 Ohms across the source coil, and around 130 Ohm's across the pick up coil.
http://www.miniriders.com/electrica...neto-igniton-coil-source-coil-pulse-coil.html

 

[mikkh]

Does the klx type cam chain fit lifans?

 

[my67xr]

No, it's totally different

KLX cam chain-

Lifan cam chain

 

[mikkh]

I know the difference myself and that the KLX chain should be stronger. Is the pitch same? By feel it seems like. About the ORK I´m thinking to lighten the 1 kilo flywheel to about 600 grams and use the the 5 pole yx stator to use the 8 pin CDI.

 

[my67xr]

I'm not sure how the 8 pin cdi will react to getting 23x the power from the YX stator
Or 3x times the power from the YX trigger coil, i think it may burn out the cdi.

How are you going to remove 400 gram's from the flywhel?
I lightened a 125 flywheel year's ago, had it turned down on a lathe, the most they could safely take off was 150 gram's

 

[mikkh]

What if I would use less magnets on the stator? Then it would be lighter and make less power. The engine revved quite good with the 1kg flywheel. It had massive compression. But the clutch cover doesnt fit because of the 6 plate clutch. Looks like I´ll have to use Z160HO clutch cover?

 

[my67xr]

The magnet's are all bonded to the flywheel in one go, so trying to take half out will probably damage the bond of the one's left.
Also they are spread in the flywheel so that they all help to hold the next one in.


I had a 125 stator flywheel on my 150 Lifan for a little while, it revved ok, but the kick back was hard sometime's.

 

[my67xr]

I just compared 3 rear clutch side cover's side by side, from the top Lifan 150, Daytona Anima and Z160H0

You might be able to swap clutch cover's if you use the complete Z160HO cover as the bolt pattern is different
There is also the difference of the Lifan 150 having the oil line's coming off the side cover, and the Z160HO oil line's come off the case.
And i have a funny feeling that the crankshaft is slightly longer on the Zongshen engine
I'm not 100% sure it will work still as i've never done it myself.

 

[mikkh]

Yep planning to use the whole cover. The all covers should have the same bolt patterns on the case? What mm are the Zongshen banjo bolts? The flywheel is now 750g and there is a small room for improvement. Could end up as 650g hopefully. How I could use better ignition curve CDI with the big flywheel?

 

[my67xr]

The cover's are the same pattern yeah.
A new Lifan 5 plate clutch cost's $50 but a new side Z160 cover is around $100
You'll need 1 longer bolt and 1 shorter bolt too to swap cover's
The oil cooler hole's in the case of the Z160HO for the oil line's are M8 x 1.25





The only way i can see that you can use the 5 coil stator with the Daytona 8 pin cdi is if you stripped baxk all the copper winding's of the stator you have now and rewound it with a lot less winding's to give you the same Ohm's reading as the Lifan 150 / Z160HO stator's

 

[mikkh]

Well then I would have to use the head mount oil radiator if I choose the Z160HO side cover. Guess I´ll try to just grind the clutch cover to make it fit (needs about 2-3mm to fully close) and use two or more side case gaskets. And the wavy washer was thicker on the Z160HO clutch, should I use Z160HO primary shaft too?

 

[mikkh]

How the Z160HO clutch cover looks from the inside compared to Lifan 150? What is the spacer for in the Z160HO clutch kit?


Edit: The spacer goes between the crank gear and the castle nut. The Z160HO crank right end is indeed longer.

 

[mikkh]

Does the 3 valve head have the same stud pattern as the big valve 27/23 crf style heads? Thinking about making a spacer for the cylinder and using it on the lifan 150/140 bottom end.

 

[gottagetacheaperhobby]

Wont you then need to get a custom piston made, or cut the valve reliefs your self? Seems like a lot more work than necessary. Port your stock head, add some tb valve springs and b done with it...

 

[my67xr]

Mikkh, you sound like you are quite keen on making a 'Frankenengine' for your WPB, lol.

The 3V head has 2 bolt's on the cam cover side to hold it to the bore as well

 

[mikkh]

Tried to fit the engine into the frame and the footpeg mounts dont line up with engine (they lined up with 120cc and 70cc engine). So does the Lifan 150 have different mounts? Thinking just to use a big hammer and tweak the frame a little.

Well the bigger hammer sorted that. Has anybody tried using 520 chains on pitbikes?

 

[my67xr]

No the engine mount's are the same from a 50cc right up to the 190's, it's just whether your frame has enough room to run a rear clutched engine or not (clutch arm clearance).

There's no point using the thicker/heavier chain's unless you are wanting to get rid of a bit of horsepower.
I run a DID 420 NZ3 on my 190cc bike and i still haven't had to readjust it after a few hour's of riding.

 

[mikkh]

Well assembled the frame today. Now I just have to bolt up the oil cooler, connect the clutch cable and wait for the OKO manifold adapter (the one I bought is too large for my manifold).

Little bit of offtopic: I´m thinking about building 10/12 wheeled A swingarm type pitbike with Elka rear shock. Is it even worth thinking? Or the H swingarm beats the A swingarm without any questions? Could somebody recommend me hubs and spokes for 10/12 setup (thinking about using them for SM pro wheels)?