Low idle

[CB450_Lor]

I've just recently purchased a '73 CB450; as well as being new to mechanics, i'm also a riding noobie. Ever since i bought this bike, i've been having trouble starting it!! (how can i learn how to ride it when i cant even start it to begin with?!) the electric start has only worked twice for me out of the billion times i've tried n the kick start seems to be the most dependable way to start it(but still not as successful as i'd like it to be). The bike idles really low and doesn't stay running for long; w/in a minute or so, it dies UNLESS i give it a little gas. Even my experienced biker buddies who take it for a test say that it needs a constant boost w the throttle at stop lights or it'll die. what could the problem be? the owner of the bike before me said just had the carbs cleaned this May. She even had reciepts. Btw, how much does it cost to get ur carbs cleaned n synched?

 

[Sonreir]

I'm assuming you're using the choke?

 

[surffly]

Sounds like you should find the factory manual, either download or buy a hard copy, and read it. It will literally walk you though tuning the bike

Its also important to understand that even if the bike is 100% as new, it will not run in the same way that a brand new bike runs.

 

[jwarriner]

I'm assuming you're using the choke?

This is an important question. All Hondas should need choke until warm, even if it's 100 degrees out.

Is the bike running on both cylinders?

You can adjust idle speed and quality with the throttle stop and idle screws. Set the idle screws to stock specs for your bike. Start it with the choke and see how it does.

 

[CB450_Lor]

Low idle

Thanks guys!!! I dont have the manual atm but i'ma def get it asap! I did use choke n it was warmed up for sure too. i'll play around w it this weekend w the manual at hand. i'm excited to get into this bike!!!

 

[hillsy]

There should be an idle adjustment screw on your carbs somewhere (it should have a knurled knob you can turn by hand). This adjusts the idle RPM. My guess is this is set too low or might be missing altogether.

 

[habib]

what do the plugs look like? Could be a timing issue, compression, or carb. I had a similar issue on my cb350. My float height was high in my left carb causing it to foul and die at idle. Additionally my timing was retarded as well.