Quick air box question '82 xj750 Max

Could someone tell me the measurement of the inlet hole in the air box lid? Thanks in advance.

 

If I had one, I'd be glad to, sorry.

 

Yuh, just need to grab my calipers, run out the garage, and dig it out of the parts bucket. Will do and edit this with the info.

Edit - each hole is 52.3mm diam. the left and right pairs have 21.3mm between them. The center two have 32.2mm between them. The middle holes are maybe 2mm higher than the outer 2.

These measurements are from a 1981 XJ750RH, but I believe the 82 750 maxim has the same engine, carbs, and airbox (or same dims at least). Measurements are probably only good to +-.5 mm. My caliper is much better than that, but the numbers varied nearly that much after I let the airbox warm up inside vs measuring it in the garage where temps are below zero.

Edit - der, reading again, looks like you want what, the snorkle dims? The dims of the opening to the air filter holder? Not quite sure, but seems like you didn;t need the numbers I gave.

 

Yeah, thanks sebwiers, but I was asking about the hole in the air filter box. I think it's about 1x3. Does that sound right?

 

Again, there's a lot of holes... you mean the opening in the cover that has a tube leading into the airbox (AKA snorkle)? I'll grab mine and see, but yeah, that's a ba'lpark figure.

 

The tube is rubber, so its exact dims are .. not. Inside opening is 22mm x 52mm, +- 1mm. Short ends are semi-circular, so its a 22mm x 30mm rectangle with halves of a 22mm diam circle on the ends.
Its 82.5 mm long.

The opening it fits in isn't an exact kinda oval, its slightly squashed towards rectangular. Max dims are 61.7 mm x 38.5 mm. If you need the exact shape, I could scan it and post a PDF of the image that will print actual size.
So I guess the "1x3" number is off - its pretty close to 2.5 x 1.5
Its got a 7.5 mm thick lip that would be needed to hold the snorkle in place, since the retaining grove on the snorkle is that wide.

If you are planning on duplicating the airbox performance, you can't just have a box with a hole the same size; it needs to have the same resonant frequency. Easiest way to do that is stick to the same volume and an inlet tube of the same cross section and length. I'm planning to do that, haven't measured my box for volume yet.

 

Thanks, 2.5 x 1.5 is close enough for what I need.