Cobra Dragsters do or don't have O2 bung

[ljburns]

Hi everyone. I purchased a 2008 Road Star last year. It has Cobra Dragsters, Barons intake, and PCIII installed by previous owner. The bike has a flat spot at approx 10-15% throttle. The previous owner told me about this. I have had it custom tuned to fix the flat spot, but it didn't quite work out. After reading a lot online and searching this site, it sounds like I need to remove the PCIII because the stock ECU can handle in the modifications. The bike currently does not have O2 sensors installed, but I do have them with the rest of the stock parts.

The question: do the Cobra Dagsters have O2 bungs, or do I need to take the bike somewhere and have bungs installed so I can put the O2 sensors back in and remove the PCIII? I know the current version of the exhaust has them, but I wasn't sure if anyone else had an earlier set that didn't have them.
Thanks in advance.

[Shores]

Remove the PC and inspect the headers for bungs on the back side. If there are none, have some welded in. You must run the sensors with the stock ECU. It will then run great!

[grubsie]

Just like "Shores" said. The bungs need fit the 10mm 02 Sensors, can't remember the thread pitch. If you can't find the bungs, you can go to the hardware store and get the thickest nuts you can find in case you need to grind them down a bit. The trick is to make sure to get the tip of the 02 sensors to only extend approx 1/8" into the pipes. (That's the position they were in on the stock exhaust.)
I made my own bungs out of steel rod I had laying around for my Bassani True Duals.

[Carpetbagger]

The Cobra dragsters I removed from my 08 did have the bungs.

[ljburns]

Thanks guys. I'll look for the plugs in the exhaust. I "looked" once already, but I will do a better job this time. I ordered some new to me Yamaha Leather saddle bags the other, along with the mounts. I'll be doing some work on the bike this weekend.

[ljburns]

Well, the good news is that I got a chance to rub in my bike tonight. Unfortunately I didn’t find bung holes in the exhaust. I couldn’t find a weldable bung with the right size and thread pitch so I purchased a couple nuts. Is the motorcycle shop or the muffler shop a better place to have them welded on? Is there a magic spot in the pipes to add the bung or is close the the wiring harness good enough?

[roadiemort]

The muffler shop probably has the bungs too.

[grubsie]

Is there a magic spot in the pipes to add the bung or is close the the wiring harness good enough?

I first started with V&H Longshots that I put bungs in before switching to true duals.. The longshots look like they are similar in design to the Dragsters. At least good enough for bung location.

The connector for the front exhaust 02 sensor is located on the frame between the transfer gear case and the engine cam chest. I put a bung in the front header so it was just before the transfer gear case. You may have to angle it up or down a little bit to clear things.

I believe the rear exhaust 03 sensor is located under the cover that houses the starter solenoid. The rear bung should go toward the open triangle space made by the bottom of this cover, the frame and the to rear of the transfer gear case. If you do not want it to be visible like I did. You need to angle the bung down so the the 02 sensor almost touches the lower exhaust pipe. Also I had to extend wires on the on the rear 02 sensor in order for to reach the the connector. The connector extensions somewhere on the web if you don't want to extend the wires yourself.

The easiest way to figure your angles is to take one of the 02 sensors and physically hold it against the exhaust pipes at the angles you want while marking the location and angle on the pipes. It's best to use painters or masking on the pipes for marking as can always change the tape if you make a mistake.

[ljburns]

Thanks for the help guys. Looks like I have another project.

[D-Fresh]

I first started with V&H Longshots that I put bungs in before switching to true duals.. The longshots look like they are similar in design to the Dragsters. At least good enough for bung location.

The connector for the front exhaust 02 sensor is located on the frame between the transfer gear case and the engine cam chest. I put a bung in the front header so it was just before the transfer gear case. You may have to angle it up or down a little bit to clear things.

I believe the rear exhaust 03 sensor is located under the cover that houses the starter solenoid. The rear bung should go toward the open triangle space made by the bottom of this cover, the frame and the to rear of the transfer gear case. If you do not want it to be visible like I did. You need to angle the bung down so the the 02 sensor almost touches the lower exhaust pipe. Also I had to extend wires on the on the rear 02 sensor in order for to reach the the connector. The connector extensions somewhere on the web if you don't want to extend the wires yourself.

The easiest way to figure your angles is to take one of the 02 sensors and physically hold it against the exhaust pipes at the angles you want while marking the location and angle on the pipes. It's best to use painters or masking on the pipes for marking as can always change the tape if you make a mistake.

I bought a RS that had the Cobra Speedster longs already installed but the O2 sensors were not connected up. When i went to connect them the rear cable was too short to reach, but not by much. I took off the RH side cover and noticed the cable for the O2 sensor had some type of retainer clip on it to secure the wire. I disconnected the retainer clip which gave the cable just enough length to reach the O2 sensor connector and then i didn't have to make/buy an extension cable. When i checked into the extension cables from Cobra they were like $40 or $50, which sent me on the quest to find another solution. I don't know where the O2 sensor will land on your pipes but if the rear cable is only a couple of inches too short you may want to see if you have some more slack in the cable before buying extensions.

[Shores]

I bought a RS that had the Cobra Speedster longs already installed but the O2 sensors were not connected up. When i went to connect them the rear cable was too short to reach, but not by much. I took off the RH side cover and noticed the cable for the O2 sensor had some type of retainer clip on it to secure the wire. I disconnected the retainer clip which gave the cable just enough length to reach the O2 sensor connector and then i didn't have to make/buy an extension cable. When i checked into the extension cables from Cobra they were like $40 or $50, which sent me on the quest to find another solution. I don't know where the O2 sensor will land on your pipes but if the rear cable is only a couple of inches too short you may want to see if you have some more slack in the cable before buying extensions.

Same here with my duals. Also took the wire part way out of the plastic conduit.

[ljburns]

It only took 3 months but I finally got the O2 bungs welded in and everything put back together. Went for a short ride today. It was nice. Thanks for all the help.