4 Degree Timing Advance Modification
Do you recommend the 4 degree timing mod?
How do I do the 4 degree timing mod?
You may have heard of "the 4 degree timing mod", it's has been floating around the internet for years now, and I don't use it on my bikes and I will explain why!
This mod isn't terrible, but its not great. For the amount of work required and for how easy it is to FUCK UP, I recommend against it. Advancing timing makes the spark plugs fire earlier before TDC. What this means is that it allows combustion to happen a little earlier BTDC than normal settings. This will give the combustion more time create the pressure from the explosion so when its going down on the powerstroke, it tends to 'hit' a smidgen harder. This will be more noticeable in lower to mid rpm ranges. However; it will hurt high rpm. The pistons are traveling faster so they don't need that extra time to create the combustion pressure. Advancing the timing too far will cause pinging and pumping losses in the high end. Retarded timing will do the opposite, while "helping" more on higher rpm and less on lower. In regards to performance its always best to have the timing as far advanced as possible, but not to the point where it starts to ping/knock, and that's where you start doing damage. The modification, if done improperly will royally screw up your motor, especially if you don't have a trained ear and can't identify noises like a ping or knock.
Engines from the factory are already designed to change timing accordingly to a point, so whenever you do decide to advance a little or retard a little you should consider how its going to effect the engine. In most non performance bikes, 87 octane fuel is used because the stock timing setting is optimized for this fuel. Any more advance will likely cause knocking and pinging. The higher octane fuel you use the more advance you can run and not have detonation. Sometimes by leaning the WOT mixture, and advancing timing you can gain a small amount of HP, but this means your bike is now requiring higher octane fuel, and a gain is not a rule. A motor's age can also determine the effects of a modification.
Sure, advancing your timing might help, but usually doesn't help enough to make it worth the 93 octane you will need to run the bike properly.
Another factor to consider on many bikes, they incorporate a Throttle Positioning Sensor, or TPS, and a TPS will automatically advance the ignition timing at low speed and high throttle. It alters the signals being sent to your coils from your ICM (Ignition Control Module), so advancing the timing manually can drastically affect the way your TPS works.
In short, I really can't say that this is a "good" modification and give it my stamp of approval. At best it may be fun to mess with, but as the timing system on a Honda isn't operated by vacuum like a lot of older motors; the timing is set up to kick ass across all power ranges.
If you are looking for performance gains you can re-jet, put velocity stacks on, open up the exhaust; these all will give you drastic increases in performance and even spruce up the looks of your bike!