Air Box Baffle and related nonsense

My '74 air box faceplate has the baffle attached. I assume this was for noise as I haven't figured out how it would work as a flame arrestor. Anyway, I notice that my '72 faceplate doesn't have one, and the replacements from Old Britts do not have it either.

Two questions: Does anybody have a compelling argument for leaving this feature intact? Does anybody want this unit badly enough to trade for one without?

This faceplate is painted. My '72 was chromed, and I have seen some with the baffle that where chromed as well. Not sure when the change was made.
I have decided to narrow my air box to 62mm from the standard 73mm. The baffle has to go!

Russ

There is no reason to retain the baffle other than continuing with out of date legal restrictions of the era so have at it as few oz lighter and a few cfm more flow and sound effects. Show us your handy work of course so we can pick it a part or nod in approval.

The baffles in the front plate are no doubt used for reducing noise emissions. It must be remembered that in the 850 Commando Norton tried various methods of cutting down the motorcycle's noise. For instance they have quieter mufflers and mutes (more restrictive), they raised the overall gearing by installing a 21 tooth gear box sprocket, and they also put in a higher gear ratio for second gear.

I have often wondered if the baffles in the plate would really make that much difference. It would be interesting if someone would do a side by side comparison of a baffled plate versus a non-baffled plate. I have a Mark IIA that I had removed the big black plastic air filter box and then installed the earlier style air filter assembly. Man what a difference this made in hearing the air intake noise! The original black plastic filter was much, much quieter than the earlier 750 style.

I imagine that the baffled front plate for the 850 Commando would make changing the air filter element very, very difficult at best. I think most people would give up a little quietness for ease of maintenance.

As far as painted versus chromed, believe from new these were painted - at least '71 onward. The one on my '72 was painted until I had it chromed in '98.

I replaced my baffled plate on an 850, there is a satisfying growl to accompany the music from the pea shooters. And air filter maintenance is definitely easier. But I did have a fire in the filter one day from a lack lustre prod on the kick starter, scary as the engine made a sqeeky sound whilst running and once I stopped her, flames emitted!
Not sure if the baffle would have helped here?
Cheers Richard

stockie2 said:

I replaced my baffled plate on an 850, there is a satisfying growl to accompany the music from the pea shooters. And air filter maintenance is definitely easier. But I did have a fire in the filter one day from a lack lustre prod on the kick starter, scary as the engine made a sqeeky sound whilst running and once I stopped her, flames emitted!
Not sure if the baffle would have helped here?
Cheers Richard

Click to expand...

Please tell us you picked up five horse power!

They look like my '72s parts. I've used a rattle can on these a couple times over the years but it doesn't hold up, so last time I had them powdercoated. They came out lovely and have held up well.

There was a small rubber hole plug on my backplate. Don't lose it if you find one on yours. Also, If you don't connect the oil tank hose to the right angle tube on the backplate then cap it off with one of those cap-plugs (that always come as free samples).

I know '71 and '72 at least had them painted like you have there. I have seen chrome front plates but I think these were for earlier years. (DogT knows I'm sure.) I have seen some with the front plate painted black. May have been for later years or else non-original.

The stock paper filter fits better than the K&N replacement element. I won't use K&N anything anymore.

Russ