Advancing the ignition on a 2009 GS.

[moe_tunes]

I spent about an hour yesterday morning advancing the ignition on my 2009 GS. Now that I have done it once I think it'll be a ten to fifteen minute job if I do it again. It took me about twenty minutes to find my vice grips - the previous owner had wrecked the head of one screw by using a phillips head screw driver from the looks of things...
I started out by checking the clearance between the timing plate and the pickup which was 0.40 mm.
Then I removed the timing plate, bent the clip holding the pickups' wires and unscrewed the pickup to move it out of the way.
With a combination of vice grips and a JIS scewdriver I removed the pickup mounting plate.
Other threads here talked about slotting the holes in the plate but as a first go I just drilled new holes about 1 mm clockwise from the original holes (which allows me to rotate the plate counter clockwise to have the spark happen earlier) thinking if that was too much advance I could slot the holes later.
The lower plate mounting screw also secures the clip that holds the pickups' wires so I had to drill through the side of that - not ideal but good enough for first experimentation..
There are a couple of machined points that locate the plate central to the crank so if the holes aren't drilled correctly the screws won't go in. I did it right the first time so was happy.
I refitted the timing plate to the crank, fitted the pickup making sure the wires were secured and the clearance was correct then fired the bike up. I ran it for a couple of minutes on the choke, giving it a rev or two then stopped it, checked that all screws were still tight, fitted the cover, packed up the tools and put my riding gear on.
On the fifteen minute ride to my favorite coffee shop, as I backed the choke off, I noticed the idle revs had picked up about 300 so when I parked the bike I gave it a few revs and let it settle down to idle. Yep, the idle revs had picked up 300. I turned it down to an indicated 1400rpm which is where my bike seems happiest and enjoyed a coffee.
Riding around suburbia in fourth at a constant throttle and around 4500rpm it is very obvious that the engine is running alot smoother which suprises me, I didn't expect that. It now responds to slight changes in throttle position quicker and seems to be a little bit more enthusiastic accelerating. I have also found myself having to back off the throttle a little to get back to the speed limit. I have done a couple of wide open throttle runs in second to redline with my head as close to the engine as I could get it, which must have looked odd, and haven't heard anything like a ping/detonation so Suzuki must have been very conservative with their initial setting for the ignition.

As a no cost modification I would thoroughly recommend it to anyone with the confidence and tools for such an easy job.

[herennow]

Interesting work, how much do you calculate you advanced the timing by?

Lots of the old school bikes, folks advance the timing till it pings, and then back it off til it stops.

Id use hi-octane, just in case...

[moe_tunes]

From the various threads on here I have read moving the plate 3 -4 mm advances the timing about 5 degrees so I have advanced it maybe 6...
No need for a change in fuel at all. Suzuki must have been very conservative with the initial timing.

[herennow]

Main risk for detonation is a hot day on a long uphill, with engine lugging slightly. Keep engine spinning freely and you should be good.

[chris900f]

From the various threads on here I have read moving the plate 3 -4 mm advances the timing about 5 degrees so I have advanced it maybe 6...
No need for a change in fuel at all. Suzuki must have been very conservative with the initial timing.

Yes, I hadn't seen any other threads but I measured the distance between the retaining screws 7cm, so 22cm
circumference divided by 360 = 0.061mm per degree, so 5 degrees is 3.05mm. I didn't know this mod existed, so I'm glad this was posted.

[Joolstacho]

There's the myth that advancing the ignition somehow gives better performance.
It IS a myth! You'll get a SLOWER ignition. Think about it. If the explosion begins earlier, a portion of the explosion will happen at a LOWER compression ratio, which is not good for efficient performance is it?
Race bikes generally have a more RETARDED ignition, as long as the combustion space is optimised. The point is all about efficient combustion. If you advance the ignition it might result in a longer combustion, but a SLOWER ignition of the mixture. A FASTER combustion concentrates the explosion, which is what we want for performance. The porting and combustion space should be attended to.

[chris900f]

In general "starting the fire" a little earlier gives a more complete burn so you get more power. This is due to the burn rate of the fuel. You need more advance as revs increase, to give the charge enough time to burn, as the window shrinks. If we were burning a super fast fuel like hydrogen you might be better off a few degrees after TDC.

My car has a knock sensor, under hard acceleration, the ECU will advance the ignition until the knock sensor triggers, and then it backs off a little. It's fuel adaptive, so premium will actually give you more power, because the ECU can call for more advance with high octane fuel. Regardless of the fuel grade though, the system tries to advance the ignition as much as safely possible.

Some extreme performance engines will retard the ignition to avoid detonation from very high compression ratio pistons, or a turbo or nitrous; but the retarded ignition is not making more power, it's just that the smaller loss of a few degrees of advance is made up for by the large increase in cylinder pressure.

[moe_tunes]

I have now done 2000 km's with the ignition advanced and thought I'd give an update on how it has worked out.
Some days I am mostly on the highway, some days I am mostly chasing corners on mountain roads and some days I am just riding around suburbia: my riding is mostly mixed.
The most noticeable change is that the engine feels so much smoother. I rode the bike for nearly 5 years before I advanced the ignition and now, even after 2000 km's, that is something that stands out each time I ride.
The bike seems to accelerate a bit quicker. I have no way to measure it but it feels that way and I seem to be upshifting through the gears quicker.
There seems to be a small improvement in economy. I have not been keeping detailed records of the fuel used but each time I fill up it needs less than normal going by the trip meter and my years with the bike. The change is something like 23-25 km/L to 26-28 km/L.
I haven't come across any negtives so am very happy I did it.

Cheers.

[moe_tunes]

I thought I'd give an update after 9000 km's.
Everything is still going great and I'm still happy I have done this.
I pulled the plugs to check them as it was getting close to the time they should be replaced and the earth electrode was a bit more white than usual which is to be expected as advancing the ignition does produce a bit more heat. Comparing the plugs to the ones I pulled out of the bike when I bought it the difference is slight. So I bought a pair of colder plugs DPR9EA-9 and after 400 km's they seem to be the right choice. I'll have a better idea on that after riding through the rest of the summer.

Cheers

[moe_tunes]

I have now done over 1000 km's on the colder plugs and thought I would show the change they produced. My GS has now done 126000 km's on the stock jets and as we all know Suzuki sets them up lean....

On the left is the plug I took out after I bought the bike at about 45000 km's. The earth strap is whiteish showing that the plug is running hot.

The middle plug has about 30000 km's on it - the last 9000 km's with the ignition advanced. The earth strap is a little whiter showing the plug is running slightly hotter which is to be expected.

The plug on the right is the colder plug after a bit over 1000 km's with the ignition still advanced. The earth strap is now more a grey colour than white showing the plug is running cooler which is to be expected. I haven't made any other changes to the bike.



To me it looks like the colder plug is a slight improvement even over the original.

[DarkCyDE]

Around 05 I did the same testing. For me, I went with 4° because I was changing plugs more often and running hotter then it needed to be for my liking. Still ran smooth, with out the extra heat. I was also doing a lot of riding in the Blue Ridge around the peaks of otter area.

Mike

[Armandorf]

As I am reading I now recall I always havd the tps disconnected, on a 04 wiring and unknown cdi.
It is an 89 engine.

how interacts the CDI model, signal generator lobes(believe that for California was different)?
From what I read
With tps disconnected it has a base fixed timing.

To start the CDI changes advance in relation to rpm, but tps gives a new reference to change something . Anyone know how this works?
I always had the tps disconnected and know I'm wondering how it works and will connect it in the future.

[moe_tunes]

As I am reading I now recall I always havd the tps disconnected, on a 04 wiring and unknown cdi.
It is an 89 engine.

how interacts the CDI model, signal generator lobes(believe that for California was different)?
From what I read
With tps disconnected it has a base fixed timing.

To start the CDI changes advance in relation to rpm, but tps gives a new reference to change something . Anyone know how this works?
I always had the tps disconnected and know I'm wondering how it works and will connect it in the future.

I haven't used a timing light on the bike to see what the timing does as revs change. When I get some time I'll do that.