How-To: 4 Advance Timing and Clutch Spring Upgrade - Honda Shadow Forums : Shadow Motorcycle Forum
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post #1 of 207 (permalink) Old 12-26-2012, 08:07 PM Thread Starter
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How-To: 4 Advance Timing and Clutch Spring Upgrade

Well, after the catastrophe of getting my clutch springs over-nighted ...

Okay, short story to preface the process: I spent the additional $$$ to overnight my EBC Clutch Springs from Jake Wilson (.com). That was Thursday and JW did their part flawlessly and I even helped them realize that the CSK028 kit DOES fit more models including mine ('03 ACE 750). Anyway, they were due Friday by 10:30, but delayed by weather in Louisville KY. UPS wouldn't deliver them on Saturday, so I waited until Monday @ 10:30 ... 11 ... 12 ... 1 ... um yeah, 2 frikkin 30 is when I got 'em. Ugh. Whatever.


Obviously and as always, any modifications you do to your bike are your responsibility and solely yours alone. I cannot be held liable for any errors, omissions or or damage done to your bike as a result of the following procedure. You assume any and all risk by choosing to follow this procedure. Capisce? Good. If any one notices an error, please chime in and let's get this thing modified. Thanks!

Now, why do you want to do this?
By advancing the ignition process by 4 degrees the piston receives the flame front 4 degrees sooner. Combustion happens while the piston is traveling upward. The time it takes for the 'spark' at spark plug to expand to the top and sides of the chamber allows the piston to pass top dead center before it receives the flame.

The expansion of the gasses during the period from ignition point ( before top dead center) to the flame front reception (after top dead center) increases the volume in the chamber and actually creates higher compression. This is why when the timing is advanced the higher position of the piston increases the effective compression and gives more power on the downward stroke. That equals more torque.

Keep in mind that the ideal compression for most gasoline engines is 10.5:1 for 93 octane fuel. Our VT750's are 9.0:1. That being said ... no you will not see that kind of difference in compression nor gobs of torque being handed to you on a platter. But, any HP or TQ gains no matter how small can be noticeable on a vehicle that weighs in just over 500 pounds. So bang-for-the-buck just oozes from this process if you have the time and patience.

Now you're thinking, "You don't gain power by advancing timing!" and "My engine will run hotter, won't it?" ... Technically no, and no. Tweaking your timing will not directly cause your engine to gain more power, but rather to run cooler (yes, cooler), improve gas mileage, make the motor burn cleaner and give you a better throttle response. The throttle response is where you are 'feeling' this torque gain.

I will mention too that higher-octane fuel can be good insurance when you have advanced your timing. This is because you may experience the dreaded pinging/knocking (a bad thing). But let's consider something first. The VT750's timing on these bikes have deliberately been retarded for emissions in the U.S. So advancing the timing upwards of 4, even 6 is only putting the VT750 back to it's optimal running point (basically pissing off the Al Gore society).

While I have no immediate plans to dyno-test these results, it's an old-school hot-rodding trick that pre-dates my birth, that's for sure. Plus, the math adds up and it's been tried and true.

Let's get to work now.
Advancing the timing on our beloved VT750's is a pretty simple process. There are some tutorials on the net, but this is my contribution and all of my own pics. Note, your process may slightly differ since I have aftermarket Cobra exhaust, a modified rear brake rod and forward controls. And this is being done to a 2003 Honda Shadow ACE VT750.

Parts needed:
- New Honda exhaust pipe copper crush gaskets
- New clutch springs (EBC CSK-028 or Barnett #501-75-04005) … if you’re doing this as well


Tools needed (or what I used anyway):
- Torque wrench
- 17mm wrench/socket
- 13mm wrench/socket
- 8mm wrench (or 5/16”)
- Socket wrench
- Socket wrench extensions/adapters
- 13mm socket
- 12mm socket
- 10mm socket
- 8mm socket
- Pliers
- 5/16” Allen wrench
- Flathead screwdriver
- Crowbar
- Feeler gauges
- Razor blade and/or sand paper
- Magnetic pick up tool (optional)
- Permatex Ultra Black gasket maker (or new gasket pre 2002 I believe)
- Loc-Tite (use blue, even though I show red)
- A couple lock washers (to fit 12mm bolt; unsure of washer size)
- Clean-up rags/paper towels
- Nylon/latex gloves (if you want to still be able to touch your lady later)
- Oil catch pan (clean if you’re reusing the same oil)
- Safety goggles
- Dremel tool with metal grinder bit



Not everything is shown in the pic …


1. Begin by placing the oil catch pan under the bike and removing the oil drain plug using the 17mm wrench/socket.


2. Place oil container aside if reusing oil, or properly dispose of. Reinstall the drain plug so you don’t forget later!

3. Next, remove your exhaust pipes using the 12mm socket on an extension where each pipe connects to the head. On my Cobras, the 13mm wrench and socket was used to remove the pipes from the frame bracket. Set the pipes aside out of the way. If they did not fall out or stick to the exhaust pipe, look for the copper crush gaskets inside the exhaust port of the heads. They’re there; just use a flat head screw driver to gently pry them out.



4. Here’s the old copper gasket (left) compared to the new. Notice how they flatten when you torque down the exhaust.


5. Now drop down your rear brake bracket by unscrewing the frame pivot bolt with the 5/16” Allen wrench.



6. If you have stock pegs and controls, you may have to drop those down as well (not shown as I have forward controls and they were not in the way of the casing bolts.

7. Continue by disconnecting the clutch cable from the clutch lifter arm on top of the case. I used a piece of wood to push forward the lifter arm while grabbing the cable with the pliers and pulling outward to free it. This way you don’t have to mess with adjusting the clutch cable at the hand lever.


8. Start loosening and removing the bolts that connect the crankcase cover to the engine block using the 8mm socket. You may find yourself needing to use an 8mm wrench on the bottom bolts. A 5/16” works too, as I found out because I could not locate my 8mm wrench.



9. Remove the oil dipstick if you haven’t already. The case may stick to the block as mine did. There are two tabs on the back side of the crankcase cover that you can use to pry off the case (first pic, case upside down as if pulled directly off bike towards you and flipped over towards you). I used a crowbar between the frame and the rear tab to gently break the case loose. Just put a rag on the frame where you are applying force (second pic).



10. When the case breaks free, remove it and set it aside.


11. If you have an earlier model VT750, you may have a gasket around the case either stuck to the case, or the block, or torn between them. Discard it regardless and get a new one. Or, you can seal it up later using the Permatex Ultra Black gasket maker. Later VT750’s use this as opposed to the gasket anyway. Shockingly, if you’re as lucky as me I found this inside as an extremely rare factory bonus! And no time too soon!!!


12. Moving on … Now you’re ready to dig in. If you’re NOT swapping out the clutch springs, skip step (B) that follows.

13. Step (A) – Timing Modification:
Looking at the engine you will see your clutch assembly in its cradle (the large drum to the left), and your and ignition pulse generator rotor and the ignition pulse generator (IPG) itself (gear and black box to the right). Using the feeler gauges, insert the largest gauge between the small rectangle magnet on the bottom of the IPG and the gear tooth it is nearest. It should measure somewhere between .030” - .050”. Keep this in mind as when you reinstall the modified magneto, you need to stay within this parameter.




14. Remove the two bolts holding the IPG using the 12mm socket. Holding the IPG, gently free the wire and two rubber grommets from the block.


15. So you don’t have to actually trace down the wire and remove things from the top part of your bike, just to disconnect the IPG and bring it to your work bench, you can simply cover the open engine area and surroundings to prevent any grinding dust and metal particles from intruding on these surfaces. I set my “work area” up as follows, using some cardboard, a trash bag, a paint can and a scrap piece of wood for a table top.


16. Holding/securing the IPG, use the Dremel tool with grinder stone to grind down the centering lips of the bolt holes. Grind them completely flat. The IPG is a magnet, so you will see debris sticking to it and gradually building.


17. Now here’s the important part for modifying your IPG bracket. Note the orientation of the IPG in this next picture. When done correctly, you are moving the IPG counter-clockwise around the gear. If you look closely at the picture, you will notice a black line just underneath my grinding stone on the backside of the bracket. I drew those on just to guide me in grinding. You are grinding to the left in that picture, provided your IPG is oriented in the same fashion as shown. Also as shown in the picture, I am grinding toward the IPG itself on the left side of the bracket. There is only so far you can go before the bolt head (once installed) prevents you from moving the IPG further than 6, so really there’s no worries. As you look at the opposite side (to the left in that picture), you’ll be grinding out material towards the outer edge of the bracket. Just be sure to leave enough material so as not to split the bracket and you’ll be good to go. Note the magnetic dust build up! This can all be blown off with a shop compressor, or removed with a disposable tack cloth.



18. After you have cleaned up the IPG, it is ready to be reinstalled. Use a couple of lock washers and some thread lock when reinstalling the bolts, just to prevent any movement of the IPG once locked down. I show red thread lock, although you might want to use blue as it is less permanent (permanent being the need for about 250 of heat to loosen). I only used a little.


19. Reinstall the IPG to its furthest counter-clockwise orientation by barely tightening the bolts and using the feeler gauge to verify the correct distance of .030” to .050” from magnet to gear tooth and tightening down the bolts to a final spec of 9 lbf-ft. Note the before and after pic here for you to judge your install. Ensure the wire and both grommets are back in place as well.

(continued below in next post)


82 CB900C - CB Lingo for My Road
82 Magna - My Road is Magna-ficent!
91 VLX - My Road to Bob
03 ACE - My Road to Rod


"Keep the rubber side down, unless of course you have a rubber head!"

Last edited by Aced It; 12-27-2012 at 02:00 PM.
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post #2 of 207 (permalink) Old 12-26-2012, 08:08 PM Thread Starter
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Before Modification:


After Modification:


20. The timing modification is complete. Continue to Step (B) if upgrading your clutch springs. Skip to Step (C) if completing your upgrade.

21. Step (B) – Clutch Spring Upgrade:

This is such an easy step, you’ll hate yourself for not upgrading your clutch springs while having the crankcase cover off.

22. Remove the 4 bolts holding the lifter plate with the 12mm socket. Turn each bolt about 4 rotations crossing between the bolts until they are all loose. Don’t worry; the plate doesn’t pop off in your face. The bearing may drop out of the plate, so just be careful when removing it.


23. Remove all four springs and place in the new ones. Simple as that. Reinstall the lifter plate and torque all bolts to 9 lbf-ft using the same cross pattern as when it was removed.


24. Here is the difference between stock (left) and the EBC spring (right). Note the height difference, coil thickness, etc …



25. Step (C ) – Final Assembly:
If no gasket or not using one, clean up the mating surfaces of both the crankcase cover and engine mating surface with a razor blade and/or sandpaper.

26. Run a bead of Permatex Ultra Black gasket maker around the entire perimeter of the crankcase cover; about 1/16” wide is acceptable. Run it around all the bolt holes.

27. Reinstall the cover ensuring it is aligned with the left and right alignment dowels and press into place. Did you remove the Patron? Oh, that's just me. Ha!

28. Install all the 8mm bolts tightening them until just beyond snug, utilizing a cross-pattern method. Let cure for an hour and tighten all the bolts about a turn more.

29. Reinstall your foot peg/controls (if removed).

30. Reinstall your rear brake rod at the pivot bolt with the Allen wrench. About 22-25 lbf-ft is good.

31. Reinstall your exhaust by placing the new copper crush gaskets in the exhaust port of the head and inserting the pipe with the flange on both bolts. Torque spec for the exhaust flange nuts is 18 lbf-ft and the the muffler bracket (at rear attaching to frame) is 25 lbf-ft.

32. Wait 24 hours for the Permatex to cure and then install the correct oil and quantity. Or if reusing the same oil, simply pour back in.

33. Start engine and idle for a few minutes provided no funny noises and such. Shut off and observe for any leaks around the crankcase, especially below. If none, you’re good to go.

34. Your bike should now have better throttle response and recapture some lost power that the government so graciously stole from you, even before you bought your toy.

Enjoy your inexpensive if not free modification!


Oh yeah, and while the pipes were off the bike I cleaned up the tips. Not that they needed to be off the bike for that, but I was killing time waiting for UPS. Nice, eh?



82 CB900C - CB Lingo for My Road
82 Magna - My Road is Magna-ficent!
91 VLX - My Road to Bob
03 ACE - My Road to Rod


"Keep the rubber side down, unless of course you have a rubber head!"

Last edited by Aced It; 12-26-2012 at 08:19 PM.
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post #3 of 207 (permalink) Old 12-26-2012, 08:31 PM
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Great stuff!

Black Beast = '71 CB750
Lazarus = '86 VT1100C rescued from a salvage yard.
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post #4 of 207 (permalink) Old 12-26-2012, 09:45 PM
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Your killing me, I dont have the patients to take all those pics, or do write up like that, very nice. may ask your permision to use it some time.

1999 VLX
1998 SA750
1991 NSX

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post #5 of 207 (permalink) Old 12-27-2012, 01:45 PM
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Great stuff. I just didn't quite understand step "17. Now here’s the important part for modifying your IPG bracket" specifically regarding the black guide line you drew (i didn't see it). Is what you are doing expanding the holes? I see you grind the lips off, but then did you make the bolt holes bigger?


05 VLX 600 - first bike.
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post #6 of 207 (permalink) Old 12-27-2012, 01:52 PM Thread Starter
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Quote:
Originally Posted by tgelphman View Post
Great stuff. I just didn't quite understand step "17. Now here’s the important part for modifying your IPG bracket" specifically regarding the black guide line you drew (i didn't see it). Is what you are doing expanding the holes? I see you grind the lips off, but then did you make the bolt holes bigger?
Don't confuse the "line" with what I had drawn out on the wood board. I used that for references but did not include for the sake of simplifying the procedure. Look where the Dremel grinding stone comes into contact with the hole. Just to the lower left of it you'll see the thin black marking I had drawn ON the bracket itself. I see the confusion though (and modified the post; thanks). You can use the head of the bolt flipped upside down as a guide.


82 CB900C - CB Lingo for My Road
82 Magna - My Road is Magna-ficent!
91 VLX - My Road to Bob
03 ACE - My Road to Rod


"Keep the rubber side down, unless of course you have a rubber head!"

Last edited by Aced It; 12-27-2012 at 02:01 PM.
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post #7 of 207 (permalink) Old 12-27-2012, 02:01 PM
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Thanks for the clarification.


05 VLX 600 - first bike.
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post #8 of 207 (permalink) Old 01-25-2013, 07:23 PM
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Quote:
Originally Posted by Aced It View Post
Don't confuse the "line" with what I had drawn out on the wood board. I used that for references but did not include for the sake of simplifying the procedure. Look where the Dremel grinding stone comes into contact with the hole. Just to the lower left of it you'll see the thin black marking I had drawn ON the bracket itself. I see the confusion though (and modified the post; thanks). You can use the head of the bolt flipped upside down as a guide.
ignorant question: is the spring kit & exhaust gaskets the same for the 2009 Shadow Spirit 750 shaft drive? I've only got 5K miles on it, but figure once the gaskets are compressed, and I have to take them off, I'll need replacements. I am guessing it is, but want to know for sure before I buy it.

riding since 1969, currently a 2009 Shadow Spirit !
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post #9 of 207 (permalink) Old 02-12-2013, 01:59 PM Thread Starter
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I'm adding a link in the Tech section to a friend who shows some dyno information, last of which includes the degree advance mod result. Thanks Trevor!

https://www.hondashadow.net/forum/72-...ml#post1458991

82 CB900C - CB Lingo for My Road
82 Magna - My Road is Magna-ficent!
91 VLX - My Road to Bob
03 ACE - My Road to Rod


"Keep the rubber side down, unless of course you have a rubber head!"
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post #10 of 207 (permalink) Old 02-12-2013, 03:55 PM
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no problem bud! ill try and edit the how to 4 deg mod video and get it up here as well


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