Topic: cm 450 e carb question

[latis]

Background: I removed the tank cleaned it, coated it. Killed the screen in the tank, put new screen in tank plus a new screen in the petcock bowl. I had to wait 2 week on the parts plus a few days on cleaning and coating tank. Now that everything is back together, gas runs stright out of the "overflow"? Nipple on the bottom of the main carb. I'm thinking could the float stuck open? As it had 2 weeks to dry out

Any thought?
Thanks dan

[Johnie]

If you have gas running right out the overflow I would for sure suspect the float needle and seat are dirty. Possibly stuff from the tank restore. I can not recall if that bike has the brass standpipe in the float bowl, but if so check that for cracks. Any chance the float is cracked and sucking up fuel? I did a lot of work on the CM400 carbs and I believe they are similar.

[latis]

Yeah it sounds like I need to rebuild the carbs. Although the bike runs great. Maybe I can get buy with with just removing the bowl and cleaning what I can. It's been a long time since I rebuilt a carb, I had a kd80 dirt bike as a kid.... I got pretty good at rebuilding that carb.... but that was 20 years ago

[Johnie]

You can take the bowls, float and jets out without removing them from the bike. You will need a short screwdriver with good tip to get the jets out. Be careful as the jets are a soft brass. The top cylinder of the carb comes off easy and you can clean down the throat that way. A lot of guys will use some metal polish to lightly polish up the float needle and seat. I use MAAS metal polishing paste. Good luck with it.

[latis]

thanks for your help

[Johnie]

No problem. When you get the top cylinder off the carb off you can pull out the slide and needle. No need to replace that needle. The original OEM's are better than the aftermarket ones and seldom show any wear. Just clean it up with the MAAS and you are good to go.

[latis]

I did what you said. the float is good, stops the flow of gas at the very top but flows again 3/16 to a 1/4 drop. do you know if there is a way to set the float level?

[Johnie]

To properly set the float level you would have to take the carbs off. Unless you think someone messed with the floats I would not worry about it. I never messed with mine and they ran great. I would put it all back together and see how it runs.

[latis]

I did its still leaking gas... I'll try it again

[latis]

thank you for your help. I re cleaned everything today... no gas leaks

[Johnie]

If it starts to leak again you may need new float seats and needle valve. Hope it all continues to work good for you.

[latis]

I rode for a few hours yesterday. No leaks. A few other carb problems. I'm thinking I need to clean the carbs the right way and see there that gets me.
Thanks for your help

[Johnie]

Were you able to unscrew both jets in each carb?

[Alan F.]

Maybe run some seafoam in your fuel?

[latis]

You read my thoughts I picked some up today

[latis]

No I couldn't get jets out. My screw driver was to long. But I got a smaller one now and no kids this weekend soooo I'm gonna see what I can do

[Johnie]

No I couldn't get jets out. My screw driver was to long. But I got a smaller one now and no kids this weekend soooo I'm gonna see what I can do

I used a small one and was able to attach a wrench to it. Be sure you get the right size driver so you do not mess up the screw slots. Those dang things will strip and you will never get them out if you are not careful. Mine were in pretty hard...but they were dirty and the bike ran great once I cleaned them. Use a mirror to look at the jets from the bottom. Maybe you can see if they are dirty.