Allied involvement? Only if the Czech Legion revolts, which probably wouldn't happen here, its much less anarchic. With the border further west there won't be any fear of German seizure of war materiel. Kerensky calls for an election to a Constituent Assembly as soon as it is possible... August, maybe? Meanwhile the Soviets whither away, they try to host their own elections to the Supreme Soviet or what-have-you, but it isn't as popular. The Socialist-Revolutionaries win, Kerensky probably pushes himself to become Chairman, keeping the Right-SRs in power with Kadet support. After the elections, Kornilov and others lead a military campaign to stomp out the Soviets, leading to a short civil war and White Terror against the extreme left-wing. Finland declares its independence and there is a bloody war in the country to keep it part of the Republic of Russia.
Meanwhile, Germany uses its extra troops to knock out Italy, pressure Greece, and provide support to the Middle Eastern Front during 1917. In early 1918 they launch an attack on the Western Front which allows them to capture territory all the way to the border of Paris, close enough to shell the populace. The government moves to Bordeaux, and American troops are coming in... but the French government changes, becomes Socialist or what-have-you, and agrees to an armistice. Britain and America last a while longer, but eventually come to terms now that France is out of the equation.
When all is said and done, the Central Powers have more things to worry about, holding down their territories, than to rekindle the war against Russia, which many planned to do. The Ottomans want the Caucasus and Central Asia, the Germans want to push the borders of their puppet state Poland, take the rest of the Baltics and create an independent Ukraine and an independent Finland. Romania wants Bessarabia. Instead, there are just very cold relations with the new country.
The Russian Republic will be hard-pressed. Kerensky will not be eager to give the national minorities the autonomy that was given in OTL, so there will be revolts and unrest. Reparations to the Central Powers will keep the economy weak throughout the 1920s (unless they receive American loans, which may create a Great Depression later on, however). They are probably also blamed for the defeat of the Allies. Actually, all these problems might see Kerensky ousted sooner rather than later for a Menshevik or Left-SR Chairman, who would pursue some more radical socialist policies and deal with the minorities a little better.
I wouldn't try this timeline out, though. Kerensky wasn't your guy, it really was out of character for him. He believed in a democratic revolutionary war to sweep Europe clean of monarchy and capitalism. He was definitely pro-war through and through, and the sad thing is, he wasn't very capable at all in waging war.