Yes, I'm re-installing "Tonti's revenge" airbox

[brider]

I've been running K&N's for a couple of years now, but they're kinda ugly, kinda louder than stock, and I sensed zero performance improvement on my Cal 2 Auto (no surprise there). Since I DIDN'T toss my original airbox when I swapped to K&N's like I swore I would, I'm going to go ahead and re-install it.

So I was elated to find MG Cycle actually stocks the original carb-to-airbox boots, since my originals are as hard as if they were machined from 7050-series bar stock.

And I was AMAZED that they offered a complete stock airbox assembly, and only $60 to boot! Of all things, I would've expected THAT to be unobtainable, or of so low demand that only NOS or used boxes would be available.

The memory of how difficult it was to work with has faded, so I'm going to give it another try. Wish me luck.

[Antietam Classic Cycle]

The "Tonti's Revenge" airbox was the earlier one with cylindrical filter. The square filter 'box is easy by comparison.

[bacongrease]

 Some  of Italy's engineers should be adored.


  Many should be castrated.

 

[dxhall]

My ‘90 LM V had crappy pod filters when I bought it.  It ran pretty well, and the plugs showed a good chocolate-brown color.

The bike came with the stock box.  Since I didn’t like the pods, I bought a K&N filter and installed the stock box.  The bike ran like crap and wouldn’t pull past 5000 rpm.  I pulled the plugs and they were almost white - showing a mixture that was way too lean. 

The obvious conclusion from this is that the stock box with a K&N filter flowed a LOT more air than the pod filters.

On another note, I’ve found that the best way to install the carb-to-box tubes is to first heat them with the heat gun.

[Road Rocket]

Proper jetting on somewhat new plugs will be a dull white on the tip of the insulator. After many miles the exposed porcelain may show a tan or mid brown or grey color...Readingg plugs requies lookinf deep inside, the shell color and ground electrode
 This photo shows plugs from my 79 750 Triumph after about 15 miles of fast riding....The plug shows a slightly rich mixture that is a safety factor on old air cooled stuff

[brider]

The "Tonti's Revenge" airbox was the earlier one with cylindrical filter. The square filter 'box is easy by comparison.

I was not aware of this distinction. As I said, the memory has faded so that I don't feel the pain anymore, but I recall thinking that this design couldn't possibly be any more difficult to install/remove.

[Antietam Classic Cycle]

I was not aware of this distinction. As I said, the memory has faded so that I don't feel the pain anymore, but I recall thinking that this design couldn't possibly be any more difficult to install/remove.

This is what I was referring to. Notice the many pieces that fit just so, and the rubber plenum that rarely fits well and rots away. Changing the filter is a big job, usually requires the tank off, battery out, both carbs off and then disassembling the thing piece-by-piece. Especially aggravating on a Convert with all of it's extra hoses.





By contrast, the square-fin air box is simple to change the filter on.

[brider]

By contrast, the square-fin air box is simple to change the filter on.

I don't know if that's just dry humor or if you're being serious, Charlie, but I see that square filter sandwiched between several extremely difficult-to-remove-in-place components, and I recall having to have to remove the tank and carbs, too. And I have the Auto plumbing, too.

Thanks for the diagrams, good reference.

[Kiwi_Roy]

When I bought my Convert a friend gave me one of these filters.
Several of you suggested I should question his friendship.
When I finally managed to install it I swore it was there for life LOL

[Scout63]

I’ve gone both ways, and like pods a little better for ease of maintenance.  I do respect the stock cylinder airbox though. It means not having to install a Lemans breather also.

[brider]

By contrast, the square-fin air box is simple to change the filter on.

This thread has had enough discussion but I have one more question: On the bottom of item #24 (the airbox aft of the filter element that the 2 carb elbows are attached to), there is what I THINK is a stock water drain port. I say "think" because years ago when I was using it, I plugged it up thinking "Why in the heck is there an open port for the carb boots to suck un-filtered air from right above the gritty trans breather screen?", and whatever method I used to plug it now can't be removed without damaging the box so I can't further examine it.

Has anyone else noticed this funny-place-for-a-drain?

That's all.