[willman42]

I’m trying to do a spark plug change on my 06 Speedmaster and every video I find (for some reason there are very few Speedmaster vids out there) either there is no extra rod next to the spark plugs at all, or they have just a screw down in there and that’s it.

This thing is in the way of me getting a spark plug socket down in there, and it’s not apparent (at least to me) how exactly to remove this thing without messing something up…

 

[willman42]

It's an air injection system. Your bike will run fine without it. You can buy aftermarket plugs for it, but I think if you want a budget removal, remove one and bring it to an auto parts place and compare the threads to replacement oil plugs. I think it's M12 or M14.

Sweet! Thanks for the hella quick reply!
Also, is this an aftermarket part?

 

[willman42]

So to remove the whole system I need to remove that gray metal box mounted under the frame too? Looks like that box has a hose going back to the air box- I’d need to plug that hole on the airbox too then?

Or is there a simpler way to disable the whole thing?

 

[willman42]

I think it's M12 or M14.

For the record it’s an M13

 

[willman42]

Sweet! You guys are awesome!!

 

[willman42]

So yeah I definitely thought about that vs. the $25 kit + shipping from newbonneville.com, and I'm confident I could easily get an M13 bolt for the "engine" (not sure exactly what the chamber is that it screws into... ignition chamber?).

My concern is the plastic plug for the airbox. AFAIK unlike screws/bolts there are no standards for sizing plastic holes so whatever I get would just have to be trial and error until I get something that just seems to fit. But then I worry when I put the bike under load that plug will get messed up somehow- either through vibrations, heat, weather, or maybe it doesn't provide as good a vacuum seal as I thought it did. And then I'd be on the highway with compromised vacuum in my airbox...

 

[willman42]

To the best of my knowledge the air injection doesn’t go in to the combustion chamber, it is injected just behind the exhaust valve, it’s purpose is to assist any unburnt fuel to ignite, which is why it can cause backfiring on deceleration. Fixed the backfiring on my 2015 America.

Well I like the backfiring on decel haha so maybe I should reinstall this air injection thing?

 

[willman42]

Wait so that sounds like it actually has a meaningful use- wouldn’t unburnt fuel build up somewhere without this air injection system in place burning it off?

If it’s merely an EPA mandated thing then whatever I don’t care. But if it provides an actual performance or bike health benefit then I’d want to leave it on right?

 

[willman42]

Well I guess we’ll see if the decel pop I hear is from the air injection system or the British Customs Bomber slip on exhaust.

 

[willman42]

@Andrevb this says it's for 2009-2016 models, I have a 2006. Will it work?

 

[willman42]

The 2006 does not have an ECM, so that plug is not an issue.

I was hoping this was the case, as I’m pretty sure Speedmasters switched to fuel injection in 08/09