Topic: Compatibility between the various CB550 models

[eigenvector]

I'll try to keep this from being too obvious, this being my first post here.

I've recently come into possession 3 CB550 engines (okay, truthfully I haven't bought them yet but it's not likely anyone else will get them before I do), and would like to use one of them to repair the engine in my current bike, a '77 CB550.  I just am not certain of the ability to swap between them.  I've been using Powersedge as the means of figuring out which will work for which, but unfortunately they stopped listing anything older than 1977.

The engines are 2 '76 CB550's and 1 '74 CB550.  All I'm really interested in is the cylinder head (along with the valves).  Can I expect full compatibility or did things change in '77 when they went to the K model?  I didn't think so, but wasn't sure if the '74 would be too early to fit my '77 K.

[calj737]

Carbs and intakes differ across that age range. Keep the components for the particular carbs together and you're all set.

In later years, there was a pinned rocker arm in the valve cover that had some advantages, so so inspect your(s) prior to install and choose the best condition unit. Keep rocker arms and cam together for wear pattern consistency.

Otherwise, knock your project out!

[mickwinf]

Heads of all 500/550 are the same, as are most other parts.

[eigenvector]

I'm glad to hear that.

I might as well pick up all 3 engines.  The owner isn't doing anything with them and all they're doing is slowly falling apart in his yard.

I can carve them up and horse trade them for other stuff.

[wowbagger]

Use cmsnl.com for parts comparisons. They have fiches for all years and models of the SOHC4 Hondas.

'77 CB550 K3: http://www.cmsnl.com/honda-cb550k3-four-1977-usa_model1015/partslist/

'76 CB550 K2: http://www.cmsnl.com/honda-cb550k2-four-1976-usa_model464/partslist/

'75 CB550 K0: http://www.cmsnl.com/honda-cb550k0-four-1975-usa_model465/partslist/

[Deltarider]

If you want to find out what parts are shared by the various models consult http://www.motogrid.com/pages/OemParts?aribrand=HOM
Just enter the partnumber you've found in the Parts List. Then click select model. Very convenient.