4° Degree Timing Mod
4° Degree Timing Mod
  Most modern vehicles are made with the engine timing retarded on purpose to meet stringent emissions regulations. That is why there is a large market for aftermarket ignition modules like the Dyna3000, which replaces the stock unit with one where you can set the timing to what you want. What's not so well known is that instead of paying $350+ for a Dyna3000, you can easily modify your stock ACE so that you get an aproximetly 3-6 degree timing advance... for FREE!!! It just takes a little time & effort to modify the bracket holding the pulse generator.

The really nice thing too, is that it's almost impossible to go too far advance with this mod since the bracket can only be modified so much before you run out of room to mount it, which will give you, at the MAX, about 6 degrees of advance. The Dyna3000, I believe, alllows you to go up to 10 degrees of advance. However, at that high of a setting, you are taking a risk of damaging the engine from overheating and pre-ignition. While the 4 to 6 degrees advance on this mod is perfectly safe and only really brings the engine back towards "ideal" timing conditions... something that was lost when the engine was set for emissions regulations.

Now, the mod is very simple in itself, but you have to gain access to the pulse generator, which requires you to remove the exhaust and open up the right side engine cover. That's a fairly big job, so it's best of plan this mod to take advantage of this and also do the Clutch Springs and an Oil Change as well... while you're in there already.


Materials & Tools Needed
  1. Die Grinder and/or Dremel tool with grinding bit and reamer;
  2. Bike Lift (optional);
  3. Oil Pan (Clean one if you plan on reusing the oil!);
  4. 17mm Wrench (drain plug);
  5. 10mm and 12mm Socket and Wrench (exhaust nuts and mounting bolts);
  6. 8mm Socket (engine case);
  7. Two new exhaust gaskets - Honda P/N 18291-MM5-860. (I paid only $2.50 each for them);
  8. New Right Side Gasket (Honda P/N 11394-MV1-850, about $12.00) or a tube of gasket maker. Buy the Honda stuff or Permatex brand;
  9. Three quarts oil and Filter (If doing oil change);
  10. Loctite Threadlocker compound


Step 1:

  I've covered all the steps necessary to gain access to the right side of the engine in the Clutch Spring Mod. Click the following link and follow the instructions to open up the right side...

Installing Barnett Clutch Springs

Once you have the case opened up, you can see the pulse generator at the forward end (see arrow).




Step 2:

Before you remove the pulse generator, move the crankshaft until you line a tooth up on the timing gear with the small magnetic pickup. Then take note of the distance between the tooth and the pickup. When you put the modified pulse generator back on, you need to make it the same distance. It's approximately 0.030" - 0.050".




Step 3:

  Remove the bolts holding the pulse generator on and pull the whole thing out enough for you to work on it. If you have a paper gasket, just rip it out as you need to replace the gaslet anyhow. I also pulled the generator around and up through the part of the frame the wire was routed to give me a bit more slack to work with. Cover the open engine case with a rag to prevent any debris from the grinding falling in there.

The arrows show where there are alignment pins on the bracket. We have to grind these flat first. The picture on the right shows the bracket with those pins ground down flush
Step 4:

  Next, we have to ream the holes out so we can mount the bracket and shift it over to get our advance in timing. IMPORTANT!!! - Get the orientation straight in your head before doing any reaming... the pulse generator has to move COUNTER-CLOCKWISE when looking at it installed. Thats to the left. Therefore, when you have it turned over in your hand to grind it and ream it, the slot will be cut as shown below. Just so i didn't screw anything up, I checked it three times and used black marker to mark where I had to ream before doing any cutting. Once you have that fixed in your head, ream the holes out. How far you go will effect how much advance timing you get. The amount I have done below was equal to about 3 degrees advance for me. You can grind it more and possibly get up to 6 degrees but by then when you have the bracket in place the mounting bolts will be hitting the pulse generator.



Step 5:

  The pulse generator is a big magnet, so you'll find all the shavings sticking to it after you do the grinding and reaming. To clean it off, what I did was use a piece of cloth with some sticky stuff on it. I then used shop air to blast off whatever was remaining.

Now you can mount the modified unit back on. Position it so it's sitting as far COUNTER-CLOCKWISE as you can get it. Also, I would recommend that you use locktite on the bolts and install a couple of lock-washers, since you now have the possibility of the whole bracket shifting if it ever comes loose. Once you have the bracket on, just thread the bolts in semi-snug and then check the clearances between the pickup and the tooth. Set the clearnace up the same as it was before. Also, if you haven't moved the crankshaft and you had the tooth lined up before, you'll be able to see how far advance the pickup is now. Once you are satisfied with the position of the generator, tighten the bolts.

Step 6:

  Close the right side up according to the instructions in the clutch spring mod listed above. Don't try to run the bike until you have the exhaust on and the oil topped up.

If you did everything right, the bike should start right up. I noticed that right away. Like I mentioned before, I was pretty conservative and only did 3 degrees or so of advance, but I find that is very sweet! You don't really get some magical extra horsepower... instead, the engine just seems more responsive. Roll ons are smooth and instantaneous. Starting is faster and requires no throttle. And I have $350 still in my pocket for more Bling instead of a module under my seat :-)


Disclaimer:

  The articles in the "Modifications" section of this website and those that may be posted in the forums are meant for information purposes only. These modifications are not manufacturer approved changes and they may not be legal in some municipalities. 750ace.com is furnishing this information "as is".   750ace.com does not provide any warranty of these articles whatsoever, whether express, implied, or statutory, including, but not limited to, any warranty of performance or fitness for a particular purpose or any warranty that the contents of the articles will be error-free.

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