Alternative restrictor kit (CB500)?

[stinkwheel]

Ok, am I hell paying £175 to FI international for a restrictor kit consisting of 2 jets and 2 washers for the girlfriends CB500.

Given how FI seem to have a monopoly on them and can therefore charge what they want, I'm prepared to have a go at making one for myself.

I know they INCREASE the jet sizes from 122 to 125 (oddly).

Handily, I found a picture of the washers for this very kit (someone sold one on ebay, so it's a picture of the actual kit, not just a generic picture of restrictor washers):
https://i48.photobucket.com/albums/f216/stinkwheel/restrictor.jpg

So I'll be able to work out the ratio of outside to inside diameter from the picture.

Now all I need to find is the outside diameter, so I need to know where they fit in the air inlet (measuring this should give me the outside diameter) or is it safe to assume they are the same OD as the carb choke?
https://i48.photobucket.com/albums/f216/stinkwheel/carbrubber.jpg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Alex_H]

my old cbr400 washer restrictors were a nats cock bigger than the diameter of the carb mouth, they just pushed in. I reckon you should just pop an ht lead off, dyno it and be done lol
____________________
1998 r1, ccm 644 ds, 2000 r6 ghetto track bike

[The Shaggy D.A.]

Judging by this thread, it sounds like the carb side of the inlet rubbers :-

https://www.bikechatforums.com/viewtopic.php?p=2173418
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[Noxious89123]

On my CBR, there were just inside the ends of the inlet rubbers, where they meet the cylinder head.
____________________
'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[stinkwheel]

So they go in the inlet manifold rubbers, not the airbox rubbers? Ahhh. That ought to be pretty simple then.

I make the hole in the washer 0.84 (+or- 0.5mm) of the outside diameter. So I make a washer that is a tight fit in the rubber, measure its OD and make a hole 0.84 times that size in the middle.

Slight error on the sizes but it's a safe bet that at 24k miles, it isn't making the same power as a new one anyway, which is what the restriction will be calculated on.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.