Winter engine problems

[Country_Joe]

I use two small engines in the Indiana winter. One is my 3 1/2 hp Briggs on an Arien snowblower. The other is a brand new 25 hp Kohler on a generator. I have always had problems with the snowblower. Starts on first pull...runs great for about an hour...then starts to surge as if starved for gas. My workaround is to keep further opening the needle valve to let more gas in...runs okay....then have to do it again after 15 minutes. I continue this process until it just quits. Changed plugs, air filter, and gas...but the problem persists. I have just lived with it for many years. But now I have a new generator that I had to use yesterday due to a power outage during the ice storm. And the new Kohler did the same thing...Exactly. Ran great for the first hour or so then acted as if starved for gas. Changed gas (from a new source) and ran great for a while then started surging. Only thing I can figure is it has something to do with the temperature (from 15 to 40 degrees) or with the oil I use (straight 30 weight). Any clues? I appreciate your help. Thanks

[General Grounds]

:blob3: dealer told me to use 10w30 in the winter, the only thing i could think of is the fuel selinoid could be locking up due to the cold, you could also see if you take off the precleaner may help get a little more air to carb, (kohler school suggestion). Tony

[Fish]

Next time it starts acting up, loosen the fuel cap to make sure
a vacuum is not being created. If it starts acting fine when
you loosen the cap, look for a vent hole that is plugged.
If not, drop the carb bowls and look for debris.
Fish

[Country_Joe]

Thanks guys for the suggestions...I bet my gas caps are plugged. Makes sense...now why didn't I think of that? I'll also change to 10-30w for the winter. Thanks again

[Richard Martin]

You should only be using 10w30 in the Kohler engine. 30 wt oil is not recommended because of the hydraulic lifters.