CB550f2 Airbox fittings

[andy120t]

Hi,
I'm looking for a few fittings to help me mount the airbox.
Specifically, parts 15 and 3 - which are the angle brackets that attach the front of the airbox to the frame.

And 16, which is an oval washer with a raised bit that slots into the lower mounting hole.

I'm also missing parts 25, and 26 which are spacers to stop the box being crushed between the fittings and might be rattling around, unloved and unwanted, in the bottom of a spare bix.

Finally, part 5 which is a spring thingy that holds the air filter in place.

Any help gratefully appreciated!
Andy

[Bryanj]

Andy, you dont just want the rocking horse poo, you want it chromed.
Seriously, i think you will find the bits you want are same as 500, dont make em any easier to get but expands your search a bit.
US ebay may be your best bet to get a complete assembly

[Oddjob]

I have a brand new air filter spring.

There may be a problem though, in another thread you show your carbs are being the dreaded PD version. Not 100% sure but the airbox may be different if that's the case. I may have a couple of the spacers and possibly a bracket or 2. I'd need to look in my goody bag.

[andy120t]

Is gold-plated an option?! Seriously though, the bike is a bitsa so I can make up some brackets until/unless some come along, but it would be nicer and easier to have the correct ones. On the plus side, I found some hollow bar and some spacers which are an exact fit for the crush tubes, so I can manage those here.

I'm on the PC now which makes viewing some of these diagrams slightly easier. (Tablets are great, but it's damned hard to view anything on them).

It looks then as if the brackets to mount the airfilter box are the same for both th F2 and the K3. Ken - if you do have any please let me know.

The same goes for the spring (which I can get at DS). The filter itself has different part numbers but DS shows the same filter for both bikes. I can't see any part numbers for the filter housing/box itself but they look the same.

I haven't yet pinned down which airbox (ie the bit that connects onto the carbs) I have. The diagram and linked picture of the F2 airbox on the CMSNL pages look very much like mine - however the K3 drawing also looks very similar, but sadly there isn't a piccie. Does anyone know if there is an obvious identifier?

Quite possible then that I have a mismatch of airbox and carbs to engines...be nice to pin it down!

[mickwinf]

I think the only difference between the k3 and f2 airbox assembly is the length of the carb to airbox rubbers, f2 are shorter and easily available as same as 500. The k3 ones are longer and harder to find. The alloy manifold carb to head are also different, the k3 ones dont have a screw for vac gauges and may be a different length? I might have some brackets will check.

[Oddjob]

Good summation there Mick. The plenum chamber (the black housing) is the same as the 500/550 but it's the rubber boots which differ in the K3 due to the different style carbs, as Mick says they are longer. The carbs you have fitted whilst correct for a K3 also have a handlebar choke knob instead of a lever on the side of the carbs, they are notorious for jet blockages etc and most K3 owners try and change them for the F model version. Both the 500 and 550F carbs will fit but as Mick also says the inlet manifolds differ in that the vac gauge adapter points are on the inlet manifolds on the 500/550F models but they are on the carbs on the K3 so the inlet manifolds have to be changed if you fit the earlier carbs.

Try and change the carbs if possible, they are more reliable, more power as they aren't as restricted as the PD carbs, cables are easier to find, parts are easier to find if required. They are a little thirstier as they aren't as frugal as the PD but the difference isn't worth the hassle the PD carbs give. 550F filter will fit the K3 airbox, the 500 is the better filter if you can ditch the recycling system off the engine into the airbox, all that junk at the bottom of the filter housing.  Just vent the engine to air. As the 500 doesn't have all the oily air going through it it tends to stay cleaner longer. You'd need to find a 500 filter housing though but again, not that hard to find.

I know I have one bracket from an airbox but which it is I won't know until I find it. I'll let you know.

If you want an air filter spring I can sell you mine far cheaper than DS, mine was made in Italy by a very talented engineer and looks to be either stainless steel or bright zinc plated mild steel. Either way it's a better copy than DS has, £10 inc P&P.

[andy120t]

Great! I get the feeling that mine is all F2, including the manifold (which has the carb balancing holes) but with the PD's  stuck in the mid dle.

Final thing to check is the length of the rubber boits. Mine seem fairly short and are pictured below. Any idea how long the correct ones for PD carbs are?