Topic: 1978 750 engine swap

[stevewag]

I've got a sohc 1978 cb 750 k with engine problems that are beyond my mechanical abilities. So, I'm wondering if other k sohc engines from other years are compatible as a swap without modification? Thanks in advance

steve

[seanbarney41]

77-78 k and f engines are totally bolt in swap...any other cb750 engine you will need to use the sprocket carrier from a '76 or earlier bike, then make up the extra space on the axle with a spacer(or swap the whole earlier swingarm in).  Also there is a hose size mis-match with  the hose from the back of the case to the oil tank breather.

[stevewag]

got another question about my 78' cb 750. The little canister- I think its called a condensation chamber- where the breather hoses converge, how important is that canister? Say if the canister itself wasn't there and the hoses just drained to the ground, would the engine run any differently? I'm asking because when I took it apart today to clean, the condensation element was totally desintegrated and the big o-ring was broken. The o-ring I can get, but honda doesn't make the filter anymore. Is there something else that can be put in there to replace it?

[Jerry Rxman Griffin aka MuthaF'er]

Cut a piece of foam from some packing, etc.

The canister redirects all those terrible aerosol pollutants into the air box to burn them. The foam catches whatever condenses into liquid form. Honda saved the planet with this 

[madmtnmotors]

I use the green foam filter element for a lawnmower, just cut to fit. I can usually get more than one from a single filter.