First real CB500 problem

[wa407mpp]

CB500/CB550

If I remember right the CB500 was part of the CB350/CB400 family and the CB550 was from the CB750 family so the parts may not enterchange or it may have been just the 750 transmission they used. The Honda points also had a habit of shorting out to the mounting plate so buy them as a unit if you can still get them that way ,it was such a problem thats was the way everyone bought them way back then.Also don't try to put an extra half qt. of oil in the tank,it will fit ,but when it heats up it will come out the overflow onto the rear tire.That was a big problem on the early 750's with the chain oiler from the transmission through the front sprocket I don't remember if the smaller bikes had that setup. most guys just turned it off because it made such a mess on the rear wheel.

[AlanB]

Hi WA,

Only the 750s had the oiler........I think that even they did without on the later models. Only the SOHC 750 had an oil tank; all the other Honda fours had the oil in the sump.

AlanB

[Crazcnuk]

My '77 CB750-4K did not have the oiler, although the PO added one, by breaking the chain and allowing it to take a big chunk out of the crankcase just in front of the small sprocket! I assumed the small drip WAS a chain oiler until I had the chain cover off one day and found the fibreglass patch he had fashioned was coming off...

Mine did have the Oil tank up gehind the sidecover. Mine also had the knob on the small sprocket that lifted the sidestand as you moved off.

[Tdog]

500 to 550

Hey there 81XS, Love what your doin' 500 to 550. I've done the same and it is an easy swap. HOWEVER, once you have both sets of jugs side by side you will find the 550 liners have a larger radius at the bottom requiring a larger chamfer in the top case. Long story short, by plugging, masking and covering all openings into the engine (esp. around the rods), the chamfering can be done quickly with a die grinder or dremmel tool. Also flush the engine thru the jug bores with plenty of solvent and allow it to run out the oil drain. You also need the 550 gaskets. Assemble and run it in and change the oil sooner than later and the engine should be fine. Hope this is in time to be helpful.
Regards,
Tom

[81xsproject]

How right you are about the gasket, tdog. Turns out that some time after the 550 came out, they discontinued the 500 head gasket and replaced it with the 550 head gasket. I got a good deal on a top end gasket set. To good. Turns out my set is from before the change and I got a true 500 HG. So, now I am waiting for a 550 in the mail. The good news is that all the other gaskets and o-rings are interchangeable.