Topic: CB550F Motor into K Bike

[alecholmez]

I have a 76 CB550K3, high mileage, estimated probably 35-40k. I found a really low mileage 76 550F (1,700) miles but it’s chopped to #$%* and has no title. I really just want it for the motor and maybe the tank and some other parts.

Does the super sport motor wire right up? I know it’ll fit in the frame but is the wiring different? If I remember correctly the clutch switch is different so the connector to the sub harness is different than a regular K bike? If it’s plug and play that would be optimal. Thanks for the info ahead of time!

[Ace Blackwell]

I wonder if there are any title concerns for your current bike.  The motor would have a different VIN.

[seanbarney41]

Engines are identical.  Engine numbers never match frame numbers and only frame numbers on title so no idea what ace is thinking about.

[b1jackson]

F wiring harness is different.  Much of it connects in a big lump near the coils vs. all being in the headlight bucket.

[Bankerdanny]

Yes, it is a direct swap. The only wiring that connects directly to the engine is the charging system, starter, neutral light, and oil pressure sensor and all that should be identical regardless of model.

[Don R]

 Sounds like a go on the swap. Just be sure the low mile motor was stored properly as in, kept dry and oiled.

[Stev-o]

... and only frame numbers on title

Not necessarily Sean. I bought a 550F on eBay from WI and the title had the engine number on it [and no frame number]
Other members have reported the same too.

[bryanj]

Cant be a K3 in 76 didnt come out till 77

[Bankerdanny]

Cant be a K3 in 76 didnt come out till 77

Depends on if you consider the '74 as a K0 the way we think of the '69 750K as a K0.

[Scott S]

Yes, it is a direct swap. The only wiring that connects directly to the engine is the charging system, starter, neutral light, and oil pressure sensor and all that should be identical regardless of model.

 This. Go for it. You may even be able to sell some of the F bits.
 You'll need the K model kicker.

[seanbarney41]

... and only frame numbers on title

Not necessarily Sean. I bought a 550F on eBay from WI and the title had the engine number on it [and no frame number]
Other members have reported the same too.

yeah, I knew someone would bring up weirdo Wisconsin who was influenced by native Harley Davidson who put the vin number on the engine well into the eighties.  I think some states require both frame and engine numbers on titles too.

[Stev-o]

... and only frame numbers on title

Not necessarily Sean. I bought a 550F on eBay from WI and the title had the engine number on it [and no frame number]
Other members have reported the same too.

yeah, I knew someone would bring up weirdo Wisconsin who was influenced by native Harley Davidson who put the vin number on the engine well into the eighties.

I always wondered if Harley had something to do with it...

[Scott S]

 And back in the day, each state's DMV would do whatever they wanted.  There was no "standard".
 I had a bike that was originally titled by the engine number in NC. It had tons of original paperwork, including the bill of sale from the dealer. I was able to show the SC DMV both numbers on 45 year old paperwork and they kindly changed it to the VIN.