outer rotor help

Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

longjohn66

Member
Joined
Nov 14, 2008
Messages
15
Reaction score
0
hi all
new to the forum, just got me a bike whoop
i have done a bit of work on it and now ive got a problem, hoping for some help
i removed the head for the useual resons and now i dont know what mark is tdc on this outer rotor,
it has 2 lines 1 by 3 drill points and another on the other side, which 1 should i use to time it right, at the minute im using the 1 by the 3 holes and it battles to start and wont idle., im using a keihin pe 24mm with a 110 main, not sure on the small jet.
looking forward to the replys

longjohn
 
Can you get the flywheel nut off? Then you'll be able to see the keyway in the crank. The key needs to point to your tdc marks. No need to remove the flywheel, just the nut.
 
OK heres a pic of my outer rotor from my lifan 150 !! not sure if it's the same as yours though !!

My timimg mark has a T next to it !! These don't have the F mark for firing point only the T for the timing point...

If this is no help and yours is different then the easiest way to be 100% sure is to remove the head again so you can see the piston and set it at TDC then check your markings on the flywheel...

Let us know how you go...

pic7-1.jpg
 
OK heres a pic of my outer rotor from my lifan 150 !! not sure if it's the same as yours though !!

My timimg mark has a T next to it !! These don't have the F mark for firing point only the T for the timing point...

If this is no help and yours is different then the easiest way to be 100% sure is to remove the head again so you can see the piston and set it at TDC then check your markings on the flywheel...

Let us know how you go...

pic7-1.jpg


hi an thanks for the pic and the replys , i didnt see a T on the fly wheel however it seems you are using the larger line on the mag, ill set mine to the mark and see what happens, what do you think about the jetting ? is it big enough.
could you also tell me which way is advance on the fly wheel and where have you got yours set?

many thanks

longjohn
 
Last edited:
To advance the ignition you rotate the stator backing plate clockwise ... Aways remember that the crank rotates anti clockwise so moving the pickup the opposite way means the pulser on the rotor reaches it earlier ...

The surest way to check if your main jet is right is to do throttle chop runs in top gear then do plug reads ... if it's too rich , move the needle clip up and if it's too lean , move the clip down ... The best setting is to get the plug colour right (light to medium tan) with the right sized main jet and the clip in the middle groove ... That way you can fine tune by moving the clip up or down ... IF you have to run the clip in the top groove ... go up one size in the main jet and move the clip to the middle groove ... if you have to run it in the lowest groove ... go down one size and run the clip in the middle groove ... Problems in the mid rev range are controlled by the needle shape ... and off idle and low speed running are controlled by the pilot jet and air/fuel screw ...

The fuel height in the float bowl affects the air/fuel ratio at all revs so check to make sure the float level is set right first ...
 
cactus is there anything you dont know?? seriously!!
 
well it fired up, seems to crackle and pop with near idle, i have to keep bliping to keep it running, it still wont idle even with the screw turned in?
how do i check the float level? it seems to be set at 5mm

longjohn
 
what would cause spitting back?
it seems to idle a bit better now still lumpy, could it be the engine is very tight?
ive opened the tappets a bit more 0.04 inlet 0.05 outlet, i have the air screw set at 2-1/4 turns out and clip in the middle, im not going to get chance to ride it till sunday, so i would at least like to get it to run, then check the plug.
i will be racing this bike next week so it seems im cutting it very close(supermoto)
never had this trouble before, my last 150 bike was stolen(hope they rot in hell)

longjohn
 
hi all and thanks for the replys
when i say spitting back , there seems to be a jet of fuel bieng forced back through the carb, like a splutter then it dies, i have found out the carb im using is for a 2stroke, and they are no good for 4strokes so ive got a vm 26 coming, this could be the cause of all the problems, i have checked the timing and i have got is perfect, all lined up on tdc, so it must be the carb

thanks for all the help and ill post when the new carb comes in


longjohn
 
Spitting back thru the carb can only be due to reversion (reverse flow) ... ie cylinder pressure escaping back past a bent valve , valve being held off the seat due to negative clearance or improper cam or ignition timing , a damaged seat or valve face ... it can also occur with long duration , high overlap race cams ...

In multi cylinder engines it can also be caused by a head gasket that has blown between cylinders where the compression from one cylinder rushes into another then out thru the inlet tract while the intake valve is still open ...

I've won quite a few bets with that diagnosis ... against stubborn people who thought it was the carb ... Remember ... a non accelerator pump carb is an inanimate object that can only do what gas flow into (or out of) the cylinder tells it to do ... When you see gas coming out one in the wrong direction , you don't need to be Einstein to realise that it's being blown out by abnormally escaping cylinder pressure ...
 
lol thanks for that, it does have a high lift cam not the standard 6mm one
vlave seating could be the cause as its a new engine , ill keep my eye open to see if it happens with the new carb

thanks

longjohn
 
hi all
just a quick update

new carb vm 26mm worked a treat
thanks for all the help

longjohn
 
k well I just replaced a bent intake valve in my bike, and my bike came with an inner rotor kit already on it, thing is it doesnt have EITHER "T" or "f" marks on it, and I took my pickup off and now dont know where to set it!!!!!!!
 
Yeah when you replace the head after removing it you have to set the timing marks back up properly ... but if you've altered anything such as the head gasket thickness , milled the head , the timing chain has stretched , you've swapped flywheels (even with another bone stock one off the same type of engine) ... Then you have to check that the "T" mark is aligned accurately while the piston is at at true top dead centre ... and then you have to ensure that the cam is accurately degree'd aka indexed at the right degrees in relation to the crankshaft ...

Here's a link with some info ...

DEGREEING A MOTORCYCLE CAM - Google Search

There's some more info on how to find true TDC in this link ... and even info in regards to ignition advance vs compression , jetting etc ...

MSD Frequently Asked Questions

Nobody realised that I got this info cocked around the wrong way ... LOL ... I must have been tired or something when I typed it ...

Quote [IF you have to run the clip in the top groove ... go up one size in the main jet and move the clip to the middle groove ... if you have to run it in the lowest groove ... go down one size and run the clip in the middle groove ...]

It SHOULD have read :

IF you have to run the clip in the lowest groove ... go up one size in the main jet and move the clip to the middle groove ... if you have to run it in the highest groove ... go down one size and run the clip in the middle groove ...
 
oooh, no i meant i didnt do ANY other work other than replacing the intake valve, ( the bike came with the inner rotor kit stock) and i removed the pickup for the inner rotor kit. Now when I go to put everything back together ..thats when i notice the rotor DOES NOT have ANY marks on it...nothing. the pickup is adjustable and i do not know where to set it??
 
yer i have one of these on my 150 and the T dont line up with the the mark on the casing when it is at TDC i had my neigbour look at hes a mechanic and punctured a dent for TDC is on casing and its a fair bit out
 
What you need to do if you remove the cam or head from any engine that has no "T" mark or flywheel marks ... is to find true TDC yourself and put your own accurate "T" mark onto the flywheel rotor to make timing the ignition and cam easy to do ...

IF you have no "T" mark on the flywheel rotor ... then HOW did you get the cam to crank timing set back up accurately ? ... You must have taken the head off to replace the intake valve ... IF you didn't have the crank set spot on True TDC when you re-aligned the cam sprocket mark to the head mark ... then you would have most likely bent the valve again ... LOL ...

Just getting the piston to the top of the cylinder is NOT where TDC is ... True TDC is in the middle of the crank swing (between the two extremes of top dead rock over ... dead in the centre of top dead rockover as the name states ) ...

While the piston is at the top of the cylinder ... it "dwells" there for several crank degrees either way so you can quite easily set the cam out of whack unless you know precisely where TTDC is ...

What you should have done BEFORE you pulled the head off was to line the cam sprocket mark up spot on with the the mark on the head ... then drawn a texta mark on the flywheel rotor and transferred it to the stator ... The marks have to be dead aligned up on the head at the same time that they're dead aligned on the bottom end ... WITHOUT doing that you are up shit creek without a paddle ... Doing that would have gotten things back to the way they WERE ... which is not necessarily accurate if it wasn't set right in the first place OR the cam chain has stretched ...

How to find TDC on an engine which has no timing marks on the flywheel ...

http://www.wikihow.com/Find-Your-Engine's-Top-Dead-Center-(TDC)

Info on valve adjustments ...

Engine Valve Adjustments made easy - Tech - Motorcycle Cruiser

Dan's Motorcycle Valve Adjustment

Another good link ...

netbikes Motorcycle ONLY Auctions. Motorcycles and Parts
 
Last edited:

Latest posts

Back
Top