Yes I know, why play with OEM topmounts. Well I would rather use a Tein spherical top mount (backordered for months) or an AMR custom top mount, but it looks like I have no choice at the moment so I am going to have to use the OEM tophat for the time being.

Well I have been reading a bit and read that to use the OEM ITR top mount with Koni 8041 Race on the ITR, that I have to have the rubber bushings from the stock tophat machined to 12mm, since the Koni shaft is larger than the OEM ITR shaft which is 10mm. I was also reading that the difference in shaft diameter issue is only an issue on the ITR?

If that's the case can I use a hard rubber bushing from Mugen made for another model and avoid the whole machining process? Anyone with actual experience please point me in the right direction.

I had to buy the tophats new since mine were gone about 10 years ago and I haven't bought the top mount bushings yet since I can't seem to find an answer that is concrete. Ideally if I could just buy a bushing that will allow the Koni shaft to pass through and will also fit in the OEM tophat that would be great. I don't have a machine shop that I trust to not eff things up and hand me back some wadded up 80 dollar bushings.




Thanks for any help.

Ken

 

I recently installed Koni Sport Yellows on my ITR using the OEM tophats and bushings.

As far as my process goes, I had a Irwin UNIBIT drill bit that had step increments for various hole sizes. I used that to widen the holes in the OEM bushings to the appropriate size. Unfortunately probably not the best way to do it - I ended up having to purchase another drill bit as I wore the first out (and they're about $40 a piece).

In any event, I was able to reuse the OEM bushings / tophats for my Koni install, but I'd probably recommend a trusted machine shop to actually widen those for you.

 

Pretty much every honda I have ever installed Koni Yellows on I have had to drill out the factory tophat sleeve. That's about 6 different models and I have always just used a basic HSS drill bit and a drill press. It's really not a big deal takes about 2 minutes.