texasscott1 wrote:
River, I believe the loop mode adjustments that can't be changed are there to ensure the unit is street legal. Even though those areas can't be adjusted they should ensure proper mixture ratios with the AIS removed which is something the stock unit doesn't do. Before purchasing one I would talk directly to the folks who make the Power Comander.

If Yamaha were to allow the stock unit to readjust for proper AFR with the AIS removed then it would never get past EPA testing. They are limited to producing a unit that passes when in the stock configuration.

I am in agreement with you on that Scott, 100%. Non of these units come with a programmable ROM that I know of, you can buy chips for cars or even burn them yourself, but I don't think you can get them from the factory. Knowing that, I don't need to talk to the the folks at Power Commander to know what they are doing, they are simply manipulating the o2's to go the the desired voltage an perhaps lengthening the hold times on the injectors. One of them claims their little computers have faster sampling times, like 80 times per second and it probably does.I don't know what good that does exactly over the sampling times of the factory computer. How many time a second to you need to sample the voltage on an o2? Ha!

Ok I am at a loss here!!! I thought the AIS pumps cool air into the heads to burn the fuel cleaner (lean)to meet emmisions and by disconnecting it the fuel doesnt burn as well (rich). amd I backwards or what?

Danged if I know. I was assuming that the AIS pumps air into the exhaust on the exhaust stroke.

kmb102 wrote:
Ok I am at a loss here!!! I thought the AIS pumps cool air into the heads to burn the fuel cleaner (lean)to meet emmisions and by disconnecting it the fuel doesnt burn as well (rich). amd I backwards or what?
The AIS allows air to be pulled into the exhaust port during the low pressure pulse that is created after the exhaust begins moving down the exhaust pipe. There are one-way valves in the AIS system so exhaust under pressure isn't pushed back through the system. If those valves are leaking the pipes leading to the heads will be very hot to the point of things starting to melt.

The extra air (oxygen) injected into the exhaust stream ignites any fuel that wasn't burned during combustion thus lowering HC (unburned hydrocarbons) emissions. Because of this the exhaust temperatures with a working AIS will be hotter than without.

On the carbureted engines it is the primary emission control while on the FI engines it is secondary and is used to ignite unburned fuel when the engine is richer during cold starts and bring the catalyst up to its operating temperature quicker, it continues to work though in order to take some of the load off the catalyst. It works best at idle and as with the pulse air systems that used to be used on cars somewhat less as engine speed increases.

It is supposed to be disabled during high vacuum deceleration and low vacuum heavy acceleration.

On a carbureted bike the AIS has to be disabled before checking the AFR. On FI bikes it's a different procedure altogether.

texasscott1 wrote:
kmb102 wrote:
Ok I am at a loss here!!! I thought the AIS pumps cool air into the heads to burn the fuel cleaner (lean)to meet emmisions and by disconnecting it the fuel doesnt burn as well (rich). amd I backwards or what?
The AIS allows air to be pulled into the exhaust port during the low pressure pulse that is created after the exhaust begins moving down the exhaust pipe. There are one-way valves in the AIS system so exhaust under pressure isn't pushed back through the system. If those valves are leaking the pipes leading to the heads will be very hot to the point of things starting to melt.

The extra air (oxygen) injected into the exhaust stream ignites any fuel that wasn't burned during combustion thus lowering HC (unburned hydrocarbons) emissions. Because of this the exhaust temperatures with a working AIS will be hotter than without.

On the carbureted engines it is the primary emission control while on the FI engines it is secondary and is used to ignite unburned fuel when the engine is richer during cold starts and bring the catalyst up to its operating temperature quicker, it continues to work though in order to take some of the load off the catalyst. It works best at idle and as with the pulse air systems that used to be used on cars somewhat less as engine speed increases.

It is supposed to be disabled during high vacuum deceleration and low vacuum heavy acceleration.

On a carbureted bike the AIS has to be disabled before checking the AFR. On FI bikes it's a different procedure altogether.

Thanks Scott, I went off and read about it and came back to see your post.

But the real question is, after the AIS removal and install of a programmer should I change brands of oil???????????? Just kidding. Mine seems to work fine with the AIS removed.It's a 2009.

I was wrong apparently, the power commander eliminates the o2's.

I don't know about you guys but I'd put this on just for looks. Too bad they are just for Harleys.

DynoJet Micro Display

texasscott1 wrote:
The extra air (oxygen) injected into the exhaust stream ignites any fuel that wasn't burned during combustion thus lowering HC (unburned hydrocarbons) emissions. Because of this the exhaust temperatures with a working AIS will be hotter than without.




I don't dispute but how is the extra oxygen ignited?

I bet it would cross over, just be creative in the mounting. A little pricey for me, but would be cool.