Help - difference between air filters RM250N/T

[Graeme M]

OK, I need advice from anyone familiar with the 79/80 RM250. I bought a 1980 RM250T recently to be my ride for CD9. So far so good, it seems reasonably straight with no obvious nasty surprises. But... I pulled the seat off and found no air filter element, just a blank cage. So I bought a Uni Filter element.

Imagine my surprise when no way would it fit the cage. So, after scouring the Alpha Sports diagrams, it looks like the 79 and 80 models have a different cage arrangement. The N has a single slightly conical cage, whereas the T seems to have a fixed cage in the airbox and the filter fits over this. What is not obvious is whether there is another cage/frame to go inside the filter element. I assume so as it doesn't look like it'd work otherwise.

It looks like I have a T airbox, a T element, but an N cage/frame.

What's the go here? Are they really different?

N airbox:


T airbox:

[Nobby25]

I understand your pain I have been hunting for a "N" cage, I picked one up out of what appeared to be a "T" box  from a wreckers, thinking they would be the same, but it is too small (PE?) so I  was going back to get the whole box to maybe convert over to the "T" setup. Also oldfart says that yz85 cage and filters fit the "N" so I was looking at that option to,
Nob

[Graeme M]

Well, I have the reverse problem! I am flummoxed that the T must use a cage, but no mention of it on any parts lists!!!  But then I guess I am not sure that I have a T airbox. Does the N airbox have a sort of frame fixed inside the airbox over which the filter and cage assembly fits? Perhaps my problem is that I have an N airbox and I bought a T filter.

If I have a T airbox and you have a T cage, then we could swap, cos I have a perfect N cage. Just gotta confirm my airbox is T...

[Graeme M]

Put another way Nob, the small cage you have is most likely a T one, which is what I need. My cage is too big and must be an N.

So, if my airbox is really a T, it's the T cage I need.

[Nobby25]

Graeme, The parts diagrams should tell you if you have a T box, they are very different.
I think a swap is on the cards, the one on the left is a temp i knocked up and the filter I bought for an "N", its huge




PM me if a swap works Nob

[Graeme M]

I definitely have a T airbox, and that cage looks more like what I need. Here's some pics of my filter, and the cage I have (filter does not fit cage).

[smed]

I think the cage you have is to suit the N model & is a ring in,I reckon the filter you brought is probably right & just sits on the fixed in place cage & then the washer & wingnut is fitted & thats it but i aint no Suzi guru either

[Graeme M]

Yeah that's what I thought too, especially given the cage is not listed in the parts catalogue. But no way will that filter sit in place without an inner cage. When I was looking at the bike I didn't check the airfilter and only looked after I'd bought it. All I found was the cage bolted to the inner frame, no filter at all. So yep, a ring in.

[smed]

I just had another look at the pics Graeme,I think I know the deal now,Do you remove the two 10mm headed bolts from the front of the airbox,pull out the cage assy,fit the filter over it then reassemble?

[Graeme M]

I don't believe so. The end that bolts to the airbox is way bigger than the filter. No, there is a cage that goes in the filter - you can see in the diagram above that it is sort of shown, but it doesn't appear as a separate purchasable item. I think Nob's cage is the right one for me, and mine is the right one for him. The power of the forum!