Topic: Elusive 1975 CB550F Float Needle

[bozo4onion]

I think I'm going nuts. Why do I find 550F carb. rebuild kits that will fit 1974-77 but then when I look at float needles I'm told the 1976-77 are different from the 1975 (mine btw). Why will the float needles in the kit fit all years but not the part # for specific float needles. Also anyone know why it is so hard to find 1975 550F float needles? Sources? Thanks.

[TwoTired]

Float needles are the same for all CB500 71-73 carbs stamped 627A or B, all Cb550 K from 74-76, stamped either 022A or 087A, and all CB550 F from 75-77 with carbs stamped 069A.

Float needles for the 77-78 CB550 K with PD (46) style carbs will have different needle from those above.

This applied to US models.  Don't know about other places in the world.

Cheers,

[bozo4onion]

Thanks TT. Embarrassed to ask but....where are they stamped. I just looked and only found the keihin(sp?) and JAPAN on the shaft. I'd like to have the parts before I pull the carbs. Is it possible to see the stampings w/o pulling them. Thanks

[TwoTired]

They are stamped on each carb body mount flange, top right.

[bozo4onion]

Thanks again. One more question and I'll quit. It appears most sell rebuild kits for all earlier 550s F+K up to 1977 as the same kit. I know the jets should be different but will all type float  valves fit if you change to the float valve and needle that come in the kit.  I mean to  say can you change to either type needle if you change to a matching valve seat. Thanks                       

[TwoTired]

All the earlier style carbs use the same needle and seat from the factory (from what I've seen).  Metal tipped and with a small, springed, plunger at the other end that the float tab contacts.
After-market kits sometimes offered rubber tipped float valves.
I don't know if their seat counterparts changed from the stock type or if they interchange between the two types of float valves.  I've used the rubber tipped style on car carbs, but not on SOHC4carbs.  I worry that after-market rubber tipped float valves will deteriorate with modern fuels.

I prefer the stock parts.  And, unless the stock ones are damaged, I reuse them after cleaning.  I do change all the rubber bits in the carbs.  And, Honda still offers these parts in a convenient kit.

What ever is used, the needle and seat become "married" while in use from vibration and operation.  I feel it is important that good working valves stay matched to their respective seats.

If your new kits come with both needle and seat, use them together, and adjust your float height to what your new parts require.

Cheers,

[bozo4onion]

Thanks TT, I think I got a plan now. I bet the Honda kit is $$$.

[TwoTired]

Thanks TT, I think I got a plan now. I bet the Honda kit is $$$.

Depends on where you buy.  The kits are somewhere between $14-$18 for each carb.  Though some dealers will charge more if you let them.

Cheers,

[bozo4onion]

Ah yes. 9.95/carb @ parts direct. Need bowl gaskets anyway. Ill decide which way to go w/valves when I figure why the carb. is overflowing. Gadkets and float valve kit=> $150.

[bistromath]

The K&L kits for the 550K use a different profile needle than my '75 550F has stock. That's all I know. I re-used my needles when I rebuilt my carbs.