I just finished putting my '75 CB550K back together and took it for a test run the other day. I noticed that it was running a little rough. This morning I synched them up, they were way out of wack! But I got them all dialed in to the same readings on the meter. I took it out for a spin and noticed the following issues:
- slow to get up to speed when getting on the throttle
- seems to want to sputter a bit at low RPMs
- getting up to 50mph, it seems as though it struggles to maintain a constant RPM and is not smooth
- at 50 mph, when I crack the throttle it is very slow to get moving
- accelerating out of a corner, it struggles to get up to speed when getting on the throttle.
I did all the prerequisites: valves, timing, cam chain, etc. I am running stock airbox and filter, 4-1 MAC exhaust, everything else in the motor is stock. I don't see a model number on the carbs, the only stampings on it are KEIHIN on the lsft side.
The Previous Owner had same set-up, except he had a 4-2 exhaust on it. It ran good and strong when I bought it. I did not mess with the carbs during disassembly other than to clean them up. They were actually really clean. PO said he had recently had them done before I bought it.
So, any thoughts?
?
Am I looking at rejetting?
If so, anyone with same set up who can tell what jets/needles I need?
I have never had to re-jet carbs, do the carbs need to be removed to do this? (please don't tell me that I do, that's a pain in the A$$.)
I've attached a picture of the project so far, just need seat upholstered, emblems repainted and put on, and of course the carbs tuned.
