View Full Version : cub cadet smokes

02-29-2012, 07:26 PM
My dad has a 6x4 , model 640 cub cadet , with a honda motor. It starts smoking after a 1/4 of a mile and loses power. Can anybody help?

03-01-2012, 07:59 AM
Hi packrat and welcome to our internet tractor forums. :tiphat: I'm glad you found us.

Can you pin down where the smoke is coming from? And losing power, I would do a compression check.

03-01-2012, 09:57 AM
I agree where is the smoke comming from

03-01-2012, 10:36 PM
its coming from the exhaust. Thanks

03-01-2012, 10:40 PM
its coming from the muffler. Thanks

03-02-2012, 04:13 PM
is it using any oil? what color smoke? does the oil smell like gas?

03-02-2012, 04:42 PM
To pile on with 20/20's post, is your oil level higher then the max? (due to too much oil or gas getting in).

Is it hard starting?

Do you have a compression gauge?

03-02-2012, 05:40 PM
do not have a compression gauge, white smoke and does have gas in oil. he does have trouble starting it sometimes.

03-02-2012, 07:09 PM
Cool. Easy fix.

Your carb is letting fuel pass when you're not running it. It's a gravity fed system. Probably the float. You can fix it at the carb with a bit of time and $. I'm lazy so when I have this happen, I get an inline fuel valve and shut off the gas when I'm done for the day. A $7 fix. BTW, get a snowmobile version if you can as they're good for all 4 seasons.

Next time you have it in the shop (if ever), have them fix it but I've been using the aforementioned $7 valve for years without any further issue.

You need to drain your existing oil to get that gas out. Once you do that, drive it hard for awhile to burn it out of the exhaust side of business.

03-05-2012, 11:36 AM
i want to thank everyone for your help!

03-05-2012, 04:48 PM
change the oil, started ok, idle ok, took it for a drive and took it up a hill and lost power and let off of gas and punched it and took off and ran great, stop and look at something, left it running , got back in and it started missing and loseing power again.

03-05-2012, 06:32 PM
I wonder if the rings are bad? Did it start smoking again?

03-05-2012, 08:13 PM
If the float is stuck and it's just dumping fuel you can also get those results.

Did you fix the float on the first pass or just put a valve in the fuel line so it's not dumping fuel when it's not running.

Is there gas in the oil again? Above the fill line from the oil change?

03-05-2012, 09:15 PM
could not get it to smoke, it did have gas in the oil , it has a shut off on it already, just change the oil today and shut valve off when we got done. haven't checked the float yet.

03-06-2012, 08:49 AM
I'd agree with checking the float. While you're at it why not do a carb rebuild, you'll allready be tearing into it. Carb kits are usually very cheap.