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i can't remember if you told me the model number of your engine, it's stamped into the case below the front sprocket
 
i can't remember if you told me the model number of your engine, it's stamped into the case below the front sprocket

FY139FMB
*09G00129*

Think that's right, was a bit dark.

Is there different motors?
 
i will see if i can cross referance the stators that's all.
 
sorry, it's fixed now.

no i'm pretty sure those ones wonk work on the electric start bikes


with most electric start bikes you wont even need to remove the flywheel to fit a new stator,
as the stator is bolted to the inside of the ignition cover.
so if the flywheels are the same diameter then the stators might just swap over.
 
Thanks yet again, I'll buy an electric start flywheel puller too (just in case) - so I'm ready to rock when all this stuff arrives.
 
lol,
you don't need to keep thanking me.


when you take the stator cover off the side of your motor you should see this side facing out.
it's off an old Lifan 110 semi manual flywheel i have.
click on the pics to enlarge them.

004.jpg

this side faces the engine casing, you can see one of the rollers that engages the starter motor drive in the middle.
the tab on the r/h outside of the flywheel is the crank angle sensor/pickup, and the timing marks are to the left of the flywheel.

008.jpg


maybe just check the o/d of your threads before you buy one, there were 2 different sizes iirc ?
mine pictured above has 27mm x 1mm R/H threads
 
Ok so most of the parts have arrived and I got some time today! Was wondering if the master (my67xr) could give me some advice?

The wiring hasn't been touched from stock madass, new motor bolted in but that's it.

Old Motor as it sits now
Old stator
New motor bolted in
New motor stator
100w kit from OO

What is the easiest way to finish this from here? OO racing kit? I will need an "electric start" flywheel puller of the right size correct?
 
Last edited:
the Original stator looks very close to to the OOR 100W kit

although the OOR kit wont fit your electric start engine, without removing the electric start parts


if you get an electric start flywheel puller, try swapping your Madass stator and flywheel over onto the new YX engine
 
Sorry for lack of reply...still trying to get the correct flywheel puller. Bought the 26mm and it was too small (my tape measure skills suck), so now I'm waiting on a 28mm...fingers crossed I can get it before the weekend.
 
Still waiting! But I have another (probably stupid) question in the meantime.

My motor came exactly like this.

Is the pipe with the T-bolts (circled) an oil cooler bypass or just to block it? In other words can I run the bike like this or do I need to install the coil cooler to get oil into the head? The oil cooler seems a bit gimmicky to me and kinda big - do I need it or am I asking for trouble?
 
the oil pipe is just a return line from the head.

see to the left of the pipe, there are 2x chrome bolts on the front of the side cover, they go through a short pipe that joins the inlet/outlet of the port that connects to the oil pump
i would recommend fitting an oil cooler even if it is just a small one, it will help the engine last longer

something like this would help as a minimum-
Brand NEW Silver OIL Cooler KIT PIT Bike | eBay
 
Cool thanks, the motor actually came with an oil cooler I am just wondering whether it can be run without the cooler just at the initial stage. Sounds like it is a yes.

Still waiting on that damn flywheel puller.
 
Hi again, so last questions hopefully! I've never pulled a flywheel off before so need a little guidance, I've done photos to make it easier. Flywheel puller should be in my hands tommorrow. Once again I appreciate how helpful you have been!

Flywheel
Remove nut marked with X, remove bolts market with 0's, put on flywheel puller correctly and it should pop off...have I missed anything / got anything wrong? Ignore the square.

Stators
#1 is the OO kit which has a lightened flywheel, to use this flywheel I would need to remove the timing chain etc, change electrics and swap the whole lot in and then re-time?

#2 is original Madass, easiest route here is to remove original Madass engine flywheel, install onto to the YX150, then use this part right? Can the outer casing be swapped with #3 so it matches the engine? (the madass outer casing is black / old).

Hope I am in some way on the right path, my conversions don't usually involve having to open the motor in any way haha.
 
just remove the centre nut to take the flywheel off.
those 3x socket head bolts hold the starter clutch to the flywheel, no need to remove them.


the OORacing stator doesn't suit an electric start engine.

the original madass stator doesn't look like it will fit into the silver cover, see the black box pickup to the side?
that tells the cdi when to fire, and sends power to the ignition coil.
it looks like the YX150E pickup mounts in a different place?
you might need to look inside the cover and check things out closer?

is the bolt pattern of the madass and YX150 stator coils the same ? measure from mounting bolt to mounting bolt to check
 
You're correct, I kind of figured I wasn't going to be able to use the silver cover, it won't even come close to fitting the coil inside - all good.

So you think I'm all good? Swap the flywheels over, bolt on the coil and away I go?

Is there a trick to getting the center nut off? I put a large hex key into one of the bolts and then tried using leverage to undo the nut - but it wouldn't budge. I probably just need to put more force in but I'm pretty good at breaking things doing that!
 
you can use a strap type oil filter wrench to hold the flywheel, just watch out you don't damage the raised magnet pickup.

mfFAOuZeM9Gh2_8BR0IfAGg.jpg



so the bolt patterns on the stators are the same ?
 

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