Topic: CB450 K6 tuning woes

[zoo mob]

Just got this thing running after a twenty year hiatus before I got it. New plugs, cleaned out the tank, carbs came off a '68 cl450 I had and were given a basic cleaning and jet blow out, carbs have been give  a basic on the bike sync according to the manual etc.. The plugs were sooty the first time I pulled them, and have not checked since re-doing the timing and point gab etc. Main problem right now is that it runs pretty crappy and choppy until I hit like 5000rpms. Any initial thoughts? I know that's not a lot to go on, but any insight would be welcome.

[Johnie]

Did you take the old set of points and just clean them up or did you install new points and condensor? With a bike sitting so long I would go with new and then you can eliminate that problem and move on. Are you 100% sure tank is clean? Did you line it? Pull a float bowl off and check for crap in there. Just some thoughts for you.

[tbpmusic]

Always check the battery first on a 450. It runs totally off the battery. And new batteries can be bad right out of the box, so don't just assume it's ok.
A compromised battery causes all manner of weirdness.
If it's not strong enough to use the electric starter, it's compromised and you'll just be chasing your tail until it's corrected.

Go here to read the proper timing procedure.....

http://www.hondatwins.net/forum/viewtopic.php?f=18&t=883

[zoo mob]

Just cleaned the adjusted the gap, and set the timing. I pulled the plugs, and they are super-sooty, I think my next step is new air filters.

[Johnie]

Can you check the valves on there?

[bobjohnson]

Can you check the valves on there?

Yep valves are the most important thing on the 450, if theyre off it runs terribly. Make sure theyre to spec before delving into the carb.

When it came time to sync mine, i had to use the "bang it over 1 cylinder at a time" trick even though i really hate doing it. I found its fairly impossible to hear the difference between the 2 cylinders if theyre both running, with all the other noises a 450 makes at idle. I spent about 2 hours trying to sync them both running at the same time. Once i gave up and did one at a time, took literally under 10 minutes to get them bang on perfect.