Oil filter won’t fit

I think I would be more concerned why the OEM filter would not fit

Yes since it happened with more than one filter then there has to be an issue on the oil housing spindle. Perhaps metal protruding from the filter spindle from the factory. If it is harder than the filter metal it could cut through it on each install, and remain there, causing no harm. Or what if someone smashed the end of the spindle and dulled the thread or such. A screwdriver punched through the filter to get it off? That would explain a problem at the start of the spindle. I took it merely as incidental that the final brand screwed on, but not an issue with the other filters themselves.
 
Yes since it happened with more than one filter then there has to be an issue on the oil housing spindle. Perhaps metal protruding from the filter spindle from the factory. If it is harder than the filter metal it could cut through it on each install, and remain there, causing no harm. Or what if someone smashed the end of the spindle and dulled the thread or such. A screwdriver punched through the filter to get it off? That would explain a problem at the start of the spindle. I took it merely as incidental that the final brand screwed on, but not an issue with the other filters themselves.
Next time I do the oil change, I will have to take a closer look. It's my first time ever dealing with this.
 
What were the chances of getting two bad filters in a row? Stopped by the store to pick up an OEM filter because I didn’t want another Fram filter on the busa. (Went further down the rabbit hole and didn’t like what I saw about Fram).

took the old filter out and screwed the OEM in slowly expecting it to be tight again. It screwed in a bit easier and I did not feel the tight spot I did yesterday. I applied the same even pressure as yesterday and it went on in.

NO MORE FRAM FOR ME!

Thanks to all for the suggestion and advice.
 
It says in the SM only use OEM filter, threads may differ on aftermarket filters. I'd say no harm done if you can get an OEM filter on and it stays tight. You might consider a thread restoring die if you can find one of the right pitch. I'd do that if you can't get an OEM on there without undue force. The threads might gaul if you really need to crank on it. Otherwise, you might be stuck with Frams for the life of the engine. It's possible the threads stetched from the first person who put a Fram on there. Sounds like at least one owner who replied to this thread has used Fram and back to OEM without a problem.

My guess is that the oil filter threads are metric and I do not believe they are tapered threads as you usually find on pipe fittings. There are some weird threads out there that are not exactly metric or standard and they are used on motorcycles. Threads differ in not only ppi/ppcm but in the angle the thread crest/valley are cut to. I ran into one of those weird threads installing an oil pressure sensor adaptor on my other bike. It was a pipe thread that tapered to an unusually small diameter and it was probably Japanese Standard Pipe Thread. Same thing as British Standard Pipe thread. I ran an adjustable BSPT die over the Metric threads to taper it down and it fit. Ran into exactly the same problem attempting to install an oil pressure sensor on my Yammi DT-100 back in the 80s.

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It says in the SM only use OEM filter, threads may differ on aftermarket filters.
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My guess is that the oil filter threads are metric and I do not believe they are tapered threads as you usually find on pipe fittings. There are some weird threads out there that are not exactly metric or standard and they are used on motorcycles.

Wow I had no idea, but there it is in black and white. I am unsure I would have believed the manual (sounds like a sales pitch) if someone here had not explicitly stressed this. Great stuff as always @Mythos.

This reminds me of the screwdriver issues between Phillips, JIS, Posidriv, DIN...Did the filter makers make a thread intentionally that "kinda, sorta" fits a variety of applications to limit the variety they need to make? This is egregious for such a critical application.
 
Wow I had no idea, but there it is in black and white. I am unsure I would have believed the manual (sounds like a sales pitch) if someone here had not explicitly stressed this.
I always stick with OEM filters anyway because I feel they'll be best for filtering. If I used the bikes as dedicated race tuned machines, I'd use race filters but the improvement in flow is so small, I don't think it's worth the risk of letting smaller particles through. I only change oil once a year so the cost of an OEM filter isn't a big deal. As for air filters, I have BMC race filters and I can see right through them. I might use them for racing but again, the extra 1 hp or two at peak rpm isn't worth the risk for everyday sport riding.
 
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