DIY 4 Degree Timing Advance (Pics)

[reagor]

quick note for you guys...thread a peice of rope into your cylinder through the sparkplug hole, get enough in there and it will hold your crank still so you can tighten the flywheel to proper specs, then just pull the rope

dont use rope that will leave behind lint, some type of clean poly works well

 

[slickerthanyou]

quick note for you guys...thread a peice of rope into your cylinder through the sparkplug hole, get enough in there and it will hold your crank still so you can tighten the flywheel to proper specs, then just pull the rope

dont use rope that will leave behind lint, some type of clean poly works well

Say what? :-/:-/:-/:-/

 

[reagor]

its an old trick i used to use on lawnmower engines, remove the spark plug, rotate to BDC, and feed 1/4" yellow rope into the cylinder through the sparkplug hole then you can tighten/loosen the flywheel bolt/nut without some special tool to hold the crank still

http://www.rusted.free.fr/mobylette av88 rope in the cylinder.jpg

 

[Blaaster]

Woe betides the little bit of rope that finds a transfer port and gets nipped off as the piston is forced upward.

A flywheel holder will stop that problem.

 

[reagor]

Woe betides the little bit of rope that finds a transfer port and gets nipped off as the piston is forced upward.

hence lint free poly rope and ya dont kick the bike ya just rotate the crank by hand, no sparkplug = no compression...the rope is there to fill the cylinder and stop the pistons ascent

 

[Blaaster]

What happens to the bit of plastic that is left floating around inside the cylinder.

What if it is a big chunk or maybe 2 or 3, after all there are 4 transfers that could be affected.

If you are going to jamb the piston up to stop it moving, why not move the piston down a little from TDC and add some 2 stroke oil to fill the void. It can soon be kicked out.

Either way you choose to do it, I can just imagine how much the connecting rod would complain about the pressure exerted on it.

 

[reagor]

What happens to the bit of plastic that is left floating around inside the cylinder.

If you are going to jamb the piston up to stop it moving, why not move the piston down a little from TDC and add some 2 stroke oil to fill the void. It can soon be kicked out.

Either way you choose to do it, I can just imagine how much the connecting rod would complain about the pressure exerted on it.

you dont put it all in you leave a peice hanging out and when done remove the rope, not cut a peice and drop it in, usa a climbing type braid rope your gonna need like 2ft

no more pressure than that explosion every rpm

the 2stroke oil would require reinstallation and then removal of the sparkplug

 

[Blaaster]

you dont put it all in you leave a peice hanging out and when done remove the rope, not cut a peice and drop it in, usa a climbing type braid rope your gonna need like 2ft

no more pressure than that explosion every rpm

the 2stroke oil would require reinstallation and then removal of the sparkplug

So if I get your drift, there is no chance that the end of the rope will not find a transfer and head toward the crancase, and get cut off when the piston rises, pull the other leg.

The explosion is a controlled expansive one and the piston is on the way down when full pressure is reached, not like a solid lump of rope.

Sorry but no green for this idea!

 

[reagor]

So if I get your drift, there is no chance that the end of the rope will not find a transfer and head toward the crankcase, and get cut off when the piston rises, pull the other leg.

The explosion is a controlled expansive one and the piston is on the way down when full pressure is reached, not like a solid lump of rope.

Sorry but no green for this idea!

57mm stroke = 0.187ft

53ft/lbs /.187 = 283.42lbs of pressure on rope/connecting rod/piston

1,325 lbs. is the tensile strength of 1/4inch nylon rope

and im not even factoring in contact area w/ rope

you would need to apply way to much torque on your wrench to cause any harm to my rope, you'd prob strip the nut/crank

doing a compression check should yield over 100 psi

bore is 68mm

34*34*3.1415 = 3631.574mm^2 = 5.628950 in^2

100psi * 5.63sqin = 563 lbs of force on your connecting rod just kicking your engine with no spark

so you starting your bike puts more strain on your piston rod than torquing your flywheel with rope in the cylinder

keep your green ill keep my math

 

[speedemon17]

i'm still trying to figure out whats wrong with a flywheel holder

 

[reagor]

i'm still trying to figure out whats wrong with a flywheel holder

i dont have one

 

[DLK666]

Hey guys. Thinking of doing this, im planning on going +3 to +4 degrees, i just need a conclusion on weather or not it is a safe mod to do, how many people have done it and had their bikes running fine for a year or more....and how many people have had problems.....also what are the risks? P.s im running a dmc alien pipe, 280 main jet and will soon add a uni filter

 

[Blaaster]

I am running + 4 with a DMC Alien system and have been doing so for the last 18 months.

Other than a slight increase in temp, which was controlled by raising the main jet one size, no problems have surfaced.

I may add that the engine life could be shortened as it makes the engine components work harder.

The advantage of the +4 mod is to move the power down to the low end of the pipe, and I found that the DMC likes it, as it is a low/mid pipe.

 

[DLK666]

I am running + 4 with a DMC Alien system and have been doing so for the last 18 months.

Other than a slight increase in temp, which was controlled by raising the main jet one size, no problems have surfaced.

I may add that the engine life could be shortened as it makes the engine components work harder.

The advantage of the +4 mod is to move the power down to the low end of the pipe, and I found that the DMC likes it, as it is a low/mid pipe.

Thanks, which engine components are likely to go? Also, would running a B9es not help with the increased temp?

 

[Blaaster]

Thanks, which engine components are likely to go? Also, would running a B9es not help with the increased temp?

As the charge is ignited slightly earlier there is a little more strain put on the components, everything will work a little harder.

Nothing drastic will happen, things may just wear out a little bit quicker.

No need to change the heat range of the plug a B8ES is fine unless you have some wild mods and running sophisticated fuel.

 

[DLK666]

oh yes a DIY video would be perfect! im not good with directions but more of a a visual person. but anyway yea that would help alotta ppl not just me..

Why not just google how to measure degrees(of a circle)

 

[DLK666]

As the charge is ignited slightly earlier there is a little more strain put on the components, everything will work a little harder.

Nothing drastic will happen, things may just wear out a little bit quicker.

No need to change the heat range of the plug a B8ES is fine unless you have some wild mods and running sophisticated fuel.

Thanks blaaster. Has anyone with a ported cylinder and modded head run the timing mod? Im thinking of doing it cause the the port moved all my power up and theres very little low and mids? Will it be safe?

 

[Blaaster]

Have not tried advance with a ported jug, but with a re chambered head it is advisable to run stock timing to avoid detonation.

 

[Kent Hall]

This is from another website just thought it would be a good DIY here before the other website disappears.


#1 Unplug the connections for the stator wires behind the frame tube next to the CARB.

#2 Remove the stator cover

#3 Remove the flywheel and keyway.

#4 Mark the original stator position with a scribe as in the pic (the red line marks the stock timing location)

#5 Next remove the stator plate by removing the two mounting bolts

#6 using a scribe measure and scribe a line 3mm to the left of the mounting hole location. This will give you a 4 degree timing advance

#7 Using a round file or a grinding bit in a dremal tool widen the mounting holes 3mm to the line you just made.

#8 reinstall the stator plate and measure the marks you made in step #4 and make sure the plate can now be turned 3mm.

If you wish you can slot the stator both to the left and right so it's possible to retard the timing for custom applications!

Thanks bro

 

[deeeebeeeeee]

Not to resurrect an old thread, but while doing some reading and research, I saw some dyno curves that showed both 2.5 degree advance and 5 degree advance from stock timing. On this particular bike 2.5 degree of relative advance showed a few tenths better peak and the same or better overall power increase than the stock or 5°rel advance. I forget the mods but the bike was only up 3-4 horse pushing around 21.5 peak hp, should be about the same as intake, jetted and piped, maybe mild port work. My thoughts are the higher the advance the higher wear on the engine, making a less is more approach to the timing mod maybe the better approach. Mod the stator to add up to 4 degree advance but mark and try 2 and 3 degrees as well, might feel just as good/give the same or better results on timed runs with slightly less advance.
The drawback to trying a few different increases is removing and installing the flywheel more than once which could be a problem for those without proper tools.

The service manual I have on page 2-11 lists stock timing at 16°BTDC is this the same for all blasters or was there certain years that used 16° stock and others that used 20°BTDC.

Anyhow I am waiting on the flywheel puller to land in my mail box and plan to do this mod, I am seriously thinking on adding 3 degrees and calling it good, I am purposely jetted a little rich and run premium pump gas. If figure it should be ok.