Total Motorcycle Community Forums

I have a 1978 Honda hawk hondamatic 400A. I am experiencing some carburetor problems and looking for advice. I recently removed the carburetors and cleaned them and replaced one of the float valves. I can get the bike running but it seems to only run when it is cold. I typical ride goes as follows.

Once started it idles and runs fine with the choke all the way out. There is a loud tapping noise which I figured valves but the oil level is fine so I haven’t worried about the tapping. After riding for a few minutes and the motor is warn the bike will kill when trying to idle with the choke on. Idles five with the choke off but starts to bog out when given gas. What I do is turn the choke off when idling at a stop light and then pull the choke out when accelerating. This seems to get me by for short 15 minute rides around the neighborhood.

Recently we experienced some hotter weather and once the motor got hot these choke adjustments quite working and the motor would kill and not start back up until the motor was allowed to sit and cool. Then it would start back up but only run for about a half mile before killing and needing to cool back down. Before killing the tapping became much more noticeable and louder.

Any ideas or suggestions would be greatly appreciated.

First off I'd adjust your valves. A lot of times motors will not want to run properly at certain temps because the intake/exhaust are out of whack.
As for it running only when cold, it seems to me you're running a bit rich. Did you set your float level properly? What altitude are you at? That makes a big difference too.

Did you check the oil? Just wondering because of the noise.