You probably don't want to drill a lot of holes in your exhaust header, but maybe you could take a length of 1 5/8" OD x 18" exhaust pipe (straight if possible, or with a bend if needed) to use as a stationary EGT testing pipe. You will have to buy an EGT meter (as cheap as $17 US on eBay) for measurement. If you don't weld, make a series of shallow cuts to form tabs around the end of the pipe fitting into the head. Bend the tabs outward to make a shallow flange for the exhaust nut. When you have the flange fitting into the exhaust port and secured with the nut, start from the furthest away part of the tube, drill a hole for the EGT probe, determine exhaust temp there, and continue the process, making new holes a few inches apart and higher each time until you get a reading of 800 C (1472* F) or higher. You can position your O2 sensor below that point on your actual exhaust header.
Misc: Everything Else Air Fuel Gauge 02 Sensor Lambda Sensor
- Thread starter Cyborg
- Start date
You probably don't want to drill a lot of holes in your exhaust header, but maybe you could take a length of 1 5/8" OD x 18" exhaust pipe (straight if possible, or with a bend if needed) to use as a stationary EGT testing pipe. You will have to buy an EGT meter (as cheap as $17 US on eBay) for measurement. If you don't weld, make a series of shallow cuts to form tabs around the end of the pipe fitting into the head. Bend the tabs outward to make a shallow flange for the exhaust nut. When you have the flange fitting into the exhaust port and secured with the nut, start from the furthest away part of the tube, drill a hole for the EGT probe, determine exhaust temp there, and continue the process, making new holes a few inches apart and higher each time until you get a reading of 800 C (1472* F) or higher. You can position your O2 sensor below that point on your actual exhaust header.
This excellent thread has drifted into magneto tapers, ignition timing and other electrical type posts.
For clarity, these have been moved to a new thread: https://www.vincentownersclub.co.uk/threads/some-ignition-timing-related-posts.11527/
For clarity, these have been moved to a new thread: https://www.vincentownersclub.co.uk/threads/some-ignition-timing-related-posts.11527/
If your silencer is shy of baffles, what's to prevent pushing a piece of small bore copper tube up the exhaust pipe to the required spot and sticking sensors on the outer end. Just a thought. Cheers, Stu.
That is a thought. For now I'm using a reverse cone contraption. It does have a baffle blocking the way, but its removable or I don't mind modifying it so a probe could be slid through it (not much of a baffle). I really need to find a used Comet pipe so I don't turn mine into an ugly looking mess since I'm starting from scratch. Bit of a catch 22 wanting to use the A/F gauge to get me into the ballpark, but also wanting an EGT reading to locate the bung. If my fuel mixture is way off, then presumably EGT would be off as well. The gauge will only be on the bike to sort the jetting, so I could try going the bunsen valve route. If Magnetoman needed to invent one for his Gold Star, then with my shorter muffler, I'm even more likely to experience reversion.
Anyone in the Vancouver section have a Comet pipe that they can part with?
Where on Pender is your cabin? My cabin is at hope bay, we are on port washington rd.
Ill take a look for a pipe. I might have one. I have put 7K miles on my comet since Robert and I played with the sniffer. The carb settings seem to be fine and could probably be checked again.
John McDougall had the bungs welded into the exhaust on his shadow and had a sensor on his handles to indicate the ratio. Someone might know how far down the pipes they were welded or have a photo that would give a sense of where they were located.
Or even a length of the spiral wound metal covering that shower unit makers use, after the liner has been removed. It might even be possible to attach a length of piano wire to one side of the end that's up the exhaust and persuade it to go up the rear downpipe. Just a thought. Cheers, Stu.
My cabin is attached to an old wood boat.
Even a knackered front pipe from a twin would do. With TIG brazing I could nurse some bungs into it and cap off the rear cylinder bit even if its a tad rusty.
I never had the pleasure of meeting John, but recall seeing a Shadow at the Tsawwassen Swap Meet with the O2 sensors.
When discussing location of the sensor bung, it was Magnetoman (over on Oldhaven's kickstart ignition advance thread) that said he needed a bunsen valve to keep air from finding its way back up the exhaust and wreaking havoc with the sender. That should have dawned on me because when assembling an exhaust system for the aforementioned boat you have to account for the possibility of reversion. More important because it can draw water back through the exhaust manifold and down into the exhaust port.
Here are two links that have to do with exhaust. WARNING both contain content that you may find disturbing.
The first has to do with anti reversion cones installed in the pipe at the exhaust port. Its not a glowing review, http://www.nrhsperformance.com/tech_arcones.shtml
The second has to do with drag pipes, but has some interesting bits mixed in about reversion and it does show dyno runs.
Maybe Magnetoman could put a thumbscrew in his tailpipe and go for a ride without the bunsen valve and see what the A/F sender has to say about that?
Even a knackered front pipe from a twin would do. With TIG brazing I could nurse some bungs into it and cap off the rear cylinder bit even if its a tad rusty.
I never had the pleasure of meeting John, but recall seeing a Shadow at the Tsawwassen Swap Meet with the O2 sensors.
When discussing location of the sensor bung, it was Magnetoman (over on Oldhaven's kickstart ignition advance thread) that said he needed a bunsen valve to keep air from finding its way back up the exhaust and wreaking havoc with the sender. That should have dawned on me because when assembling an exhaust system for the aforementioned boat you have to account for the possibility of reversion. More important because it can draw water back through the exhaust manifold and down into the exhaust port.
Here are two links that have to do with exhaust. WARNING both contain content that you may find disturbing.
The first has to do with anti reversion cones installed in the pipe at the exhaust port. Its not a glowing review, http://www.nrhsperformance.com/tech_arcones.shtml
The second has to do with drag pipes, but has some interesting bits mixed in about reversion and it does show dyno runs.
Maybe Magnetoman could put a thumbscrew in his tailpipe and go for a ride without the bunsen valve and see what the A/F sender has to say about that?
Last edited:
John'Shadow
John put these on and left them on. I have no Idea if he intended to remove them but they were on his bike for a few years. These pictures were taken at the NA Rally at the Gorge in 2013.