Speaking of speed... broke 83mph today... - Page 4

IronFist · 01-31-2008, 10:55 AM

No 5 is alive!?
Just cold.

bronevaya · 02-20-2008, 11:33 PM

http://www.dirtbikemods.com/mini_bik...ng_advance.php

would something like this work??

I really want to try this

knothead · 02-27-2008, 07:13 PM

Quote:

Originally Posted by bronevaya

http://www.dirtbikemods.com/mini_bikes/mods/timing_advance.php

would something like this work??

I really want to try this

Yep, that's the idea. I wound up replacing the key after partly shearing mine and while I was in the case I moved the timing pickup. Works well, BUT the motor really doesn't like to be run at the rpm's it can hit with the timing advanced!! I can run mine up over 9000 r's in 5th gear now, even for very short runs at those speeds I wind up with valve noise afterwards. With a gearing change it would be a really good mod.
I helped a freind adjust the timing on his Honda Rebel, it was almost exactly the same as my Lifan.
BTW, after I reset my timing, I got the bright idea to drill out the muffler. Actually, I think I lost some power when I did it, even with enrichening the mixture.
Cliff Notes Version: Bumping up the timing works well for more power but to get any real benefit higher gearing is needed.

MATT · 02-27-2008, 09:18 PM

do you have the overhead cam or the pushrod?

mebigdave · 02-28-2008, 12:43 AM

Did you take any pics of the timing change? Did you just file out the holes on the pick up about 3mm and tighten it up again in the new advanced position? Did you do anything to the fly wheel? Are you still able to wheelie the bike like you did when you sheared the key? What valve/ tappet noise are you talking about? Is it "pinking"? Is it valve bounce? Would harder springs make any difference? Does the seem much hotter after a ride.

Would you recommend doing the mod to the 163FML or 169FML? (which one do you have?)

bronevaya · 02-28-2008, 01:12 PM

I have a dinner plate of a rear sprocket, and I have tons of hills in my area, so I think I can really benefit from this. (there is a hill, and going up it I want to say the rpms are at around 1K, its that steep)

how do you go about removing the cover off the left side? (I dont want to undo any bolts I dont have to)

knothead · 02-28-2008, 03:22 PM

Quote:

Originally Posted by MATT

do you have the overhead cam or the pushrod?

Pushrod. But the same trick should work on any of them. I plan of doing it to my Yamaha TDM which it a double overhead cam, five valve per cylinder twin. I know it works on the FZ1, which uses nearly the same setup.

knothead · 02-28-2008, 03:43 PM

Quote:

Originally Posted by mebigdave

Did you take any pics of the timing change? Did you just file out the holes on the pick up about 3mm and tighten it up again in the new advanced position? Did you do anything to the fly wheel? Are you still able to wheelie the bike like you did when you sheared the key? What valve/ tappet noise are you talking about? Is it "pinking"? Is it valve bounce? Would harder springs make any difference? Does the seem much hotter after a ride.

Would you recommend doing the mod to the 163FML or 169FML? (which one do you have?)

No pics. I had time one day and just decided to tear into the bike on a lark. There's not much to see. Once you have the cover off the pickup is right there, two bolts hold it in place, take those out and use a drill, a dremel or a small round file to make them oval. IIRC, the stator turns counter clockwise, the pickup needs to be moved forward (against the direction or rotation) 2 or 3 mm to advance the timing. Just watch out as the clearance between the pickup and trigger is important and you don't want to change it.

Yeah, it still wheelies pretty good, but after I drilled the exhaust it seemed to loose a bit of grunt in the bottom half of the RPM range. The tapping sound I'm still not sure about, I'd bet it's in the valve train but exactly what it is is anyone's guess(if it had hydraulic lifters I'd say they had been floated, but it doesn't). I'm not taking the chance on killing the engine, so I won't rev it that high any more. I'd didn't seem abnormally hot, but it might have been running lean. After it cooled (cool to the touch) and was restarted, it sounded normal.

knothead · 02-28-2008, 03:52 PM

Quote:

Originally Posted by bronevaya

I have a dinner plate of a rear sprocket, and I have tons of hills in my area, so I think I can really benefit from this. (there is a hill, and going up it I want to say the rpms are at around 1K, its that steep)

how do you go about removing the cover off the left side? (I dont want to undo any bolts I dont have to)

You have to take the cover off of the engine, I took the countershaft sprocket cover and the stator cover off. As a minimum you might get by with just taking the shifter and stator cover off. It's less than a dozen bolts all together even with the countershaft cover.

truthfriend7 · 03-12-2008, 10:02 AM

Hey guys, it's been a while. Has anyone else tried this mod yet? I'm anxious to give it a shot. Anybody else get the same results?

ChiGongJitsu · 03-12-2008, 08:33 PM

Quote:

Originally Posted by bronevaya

http://www.dirtbikemods.com/mini_bikes/mods/timing_advance.php

would something like this work??

I really want to try this

kudos on the link, i was scratching my head a few times before this was posted up!

truthfriend7 · 03-17-2008, 08:31 AM

Does a timing change like this affect the setting of your carb?

liverchip · 03-17-2008, 11:46 AM

It might increase your idle speed. Be aware it may alsoincrease the motor's operating temp as well. Head temp tends to increase with advanced timing.

knothead · 03-17-2008, 07:29 PM

The more advance you have, the more fuel you need, but only to a point. Fuel tends to cool the combustion chamber, a lean (or one with too much timing) engine pings due to the heat not getting carried away (think of that that little bit of gasoline acting like a fine spray of cool water, quenching the heat within the chamber.... that's exactly how it works).

That said, there's a point where the timing cannot be advanced any further, not matter how rich you're running. The optimum air/fuel ratio ( called the stoichiometric mixture) ranges from something like 14: to 16:1. Too lean and the engine pings (pre-detonation.. bad news!), too rich and engine damage can happen because the extra gasoline breaks down the thin film of oil between the rings and cylinder. (One you get the mixture just right, the engine (any engine) will come alive, but that really takes a wideband O2 sensor and they cost as much as a new China bike!)

The sort version, if you have SLIGHT pinging you can richen the mixture some, if you do and it still pings, back the timing down a little at a time untill it stops. Pinging will always be at it's worst under load... WOT and/or uphill.

truthfriend7 · 03-17-2008, 11:59 PM

Well, I'm still only a few months into my motorcycling experience. Much to learn. But today I was installing new clutch plates and so I decided to try this timing advance trick. I followed the instructions from the free dirt-bike mods website posted earlier. Below is a picture of what my 200cc Roketa enduro looked like apart and the second shows the two places where I ground the holes. There wasn't much extra room to play with but I probably got it slid down about 2mm. Was down the correct direction to go? Just to clarify. I filed the top of the two bolt holes so that I could slide the sensor/pickup/whateveryoucallit down about 2mm. I then reassembled and rode. I can't tell much of a difference. Maybe a little more low end power? Nothing on the top speed. My exhaust has already been drilled. Perhaps someone can double-check to make sure I did this right. I hope I advanced the timing instead of retarding it.

03-17-2008, 11:46 AM	#58
liverchip Join Date: Nov 2006 Location: Mystery Spot Posts: 1,223	It might increase your idle speed. Be aware it may alsoincrease the motor's operating temp as well. Head temp tends to increase with advanced timing. __________________ 2009 XR650L Big Red Pig Tusk bar risers 2007 X-Moto(Jetmoto) GY250 --mods--- 15/40 sprockets UNI Pod Filter 2007 Shineray TMS 200XYi--Betsy Betsy Mods:______________________ Acerbis DHH headlight FMF Powercore pipe Uni Pod Filter
	0

01-31-2008, 10:55 AM	#46
IronFist Join Date: Apr 2007 Location: Toronto Ontario Canada Posts: 2,585	No 5 is alive!? Just cold.
	0

02-20-2008, 11:33 PM	#47
bronevaya Join Date: Jun 2007 Posts: 162	http://www.dirtbikemods.com/mini_bik...ng_advance.php would something like this work?? I really want to try this
	0

02-27-2008, 09:18 PM	#49
MATT Join Date: Nov 2007 Posts: 83	do you have the overhead cam or the pushrod?
	0

02-28-2008, 12:43 AM	#50
mebigdave Join Date: Dec 2007 Location: New Zealand Posts: 196	Did you take any pics of the timing change? Did you just file out the holes on the pick up about 3mm and tighten it up again in the new advanced position? Did you do anything to the fly wheel? Are you still able to wheelie the bike like you did when you sheared the key? What valve/ tappet noise are you talking about? Is it "pinking"? Is it valve bounce? Would harder springs make any difference? Does the seem much hotter after a ride. Would you recommend doing the mod to the 163FML or 169FML? (which one do you have?)
	0

02-28-2008, 01:12 PM	#51
bronevaya Join Date: Jun 2007 Posts: 162	I have a dinner plate of a rear sprocket, and I have tons of hills in my area, so I think I can really benefit from this. (there is a hill, and going up it I want to say the rpms are at around 1K, its that steep) how do you go about removing the cover off the left side? (I dont want to undo any bolts I dont have to)
	0

03-12-2008, 10:02 AM	#55
truthfriend7 Join Date: Dec 2007 Location: Florida Posts: 92	Hey guys, it's been a while. Has anyone else tried this mod yet? I'm anxious to give it a shot. Anybody else get the same results?
	0

03-17-2008, 08:31 AM	#57
truthfriend7 Join Date: Dec 2007 Location: Florida Posts: 92	Does a timing change like this affect the setting of your carb?
	0

03-17-2008, 07:29 PM	#59
knothead Join Date: May 2007 Location: In the land of the busted up ricebowl Posts: 815	The more advance you have, the more fuel you need, but only to a point. Fuel tends to cool the combustion chamber, a lean (or one with too much timing) engine pings due to the heat not getting carried away (think of that that little bit of gasoline acting like a fine spray of cool water, quenching the heat within the chamber.... that's exactly how it works). That said, there's a point where the timing cannot be advanced any further, not matter how rich you're running. The optimum air/fuel ratio ( called the stoichiometric mixture) ranges from something like 14: to 16:1. Too lean and the engine pings (pre-detonation.. bad news!), too rich and engine damage can happen because the extra gasoline breaks down the thin film of oil between the rings and cylinder. (One you get the mixture just right, the engine (any engine) will come alive, but that really takes a wideband O2 sensor and they cost as much as a new China bike!) The sort version, if you have SLIGHT pinging you can richen the mixture some, if you do and it still pings, back the timing down a little at a time untill it stops. Pinging will always be at it's worst under load... WOT and/or uphill.
	0

03-17-2008, 11:59 PM	#60
truthfriend7 Join Date: Dec 2007 Location: Florida Posts: 92	Well, I'm still only a few months into my motorcycling experience. Much to learn. But today I was installing new clutch plates and so I decided to try this timing advance trick. I followed the instructions from the free dirt-bike mods website posted earlier. Below is a picture of what my 200cc Roketa enduro looked like apart and the second shows the two places where I ground the holes. There wasn't much extra room to play with but I probably got it slid down about 2mm. Was down the correct direction to go? Just to clarify. I filed the top of the two bolt holes so that I could slide the sensor/pickup/whateveryoucallit down about 2mm. I then reassembled and rode. I can't tell much of a difference. Maybe a little more low end power? Nothing on the top speed. My exhaust has already been drilled. Perhaps someone can double-check to make sure I did this right. I hope I advanced the timing instead of retarding it.
	0