On my '93, the seat has a plastic lip on the front that slides under the rubber thing attached to the rear tank mount. The back of the seat has two plastic tabs with holes (see pictures). The subframe appears to have two holes in what looks like the same area that would line up with the holes in the plastic seat tabs. Are there suppose to be small posts or something screwed into the holes on the subframe for the seat to sit on? As it is now, the only thing keeping the seat from flying off while riding is me sitting on it and the tail plastic. Otherwise it will wobble around like crazy.

I pulled up some microfiche drawings showing some exploded views of parts for the subframe of this model bike, but I don't see anything that would be screwed into those two subframe holes. Am I missing something here? Here's the exploded parts view of a 1993 CBR900RR's frame and subframe.

Here's my seat and subframe.

 

The subframe should have 2 threaded inserts pressed in, 1 on each side. There was once a bolt going through the tab on the back of the seat threading into the subframe.
From the picture, it appears the inserts are pressed in but you'll have to check their condition to see why they are not being used. Sometimes the bolt would get stuck in the threads causing the entire thing to spin in the frame.

 

Thanks for the reply, Stien514. The holes on the subframe are threaded so I the inserts you speak of are still in there. The threads look to be in good shape, but it doesn't look like anything has been threaded into them in quite some time.

 

It looks like all you need are two bolts to hold the seat in place. You may want to run a thread chaser through there first just to clean things up a bit. I can't remember if they are 6 or 8mm bolts, but I know for a fact that the head size on the factory bolts are 10mm.

 

i dont even bolt my seat onto the bike either.

the only thing holding it on is like you said, the driver. although with the seat pushed all the way forward, it shouldnt come out. that lip on the front of the seat should hold everything on, unless you pull the seat back, it shouldnt go anywhere.

and on a plus side, it is easy to get to everthing on the bike without the hassle of taking the seat off everytime you wanna check the battery or fuses, or what have you.

 

This boggles the mind. Do you roll around with your clip-ons loose too?

 

Man your crazy. ^ +1 I did the loose seat thing once because i lost my bolts and i wiggled all over the place never again its dangerous to ride a motorcycle your pushing your luck making the possibility to become off balance much easier

 

never had a problem with the seat moving or wiggling or rocking side to side or anything. it stays pretty tight, unless i try and take it off or move it. i have to physically move the seat back and then kinda pop it out. if it didnt feel safe enough to ride on then i wouldnt, but i have experienced no problems so far. and if you think about it, if your falling off the seat its not the seat that is the problem, its you falling off.

i dont track ride and never drag a knee, in those circumstances i would make sure my seat is bolted on though. that would be scary. but on the street i think i'm ok.

 

Don't hate me for this, but I also rode without the bolts in my seat.

I think someone had stolen them from my bike, or I had forgotten to put them back in (doh!)

Either way, I didn't even realize they were gone. But now they are bolted in.

Or at least one bolt is in.

 

I don't track ride or drag knees earlier but i do move my body around turns because i sure do like to lean and use all of my tire
Im not falling off the bike i just push my bike to its potential or mine but eventually the bikes