If France and Spain only provide some loans and weapons and they do not get involved (I assume this goes with the Dutch too), then the British are favored to win this war. The USA's allies during the war were able to tie down British forces that would've gone to putting down the rebellion, but they had to defend their holdings from the French, Spanish, and Dutch. Furthermore, without the French Navy at Yorktown, which allowed the American-French forces to defeat Lord Cornwallis' forces and prevent him from retreating.
Using Wiki for the numbers, on average the USA's army were around 40,000 troops (with 200,000 serving over the course of the war), and the British had 48,000 at its peak in the USA and 121,000 globally in 1781. Furthermore, the British had the help of 25,000 loyalists (total served), 2,365 Hanoverians (total served), 29,875 German Mercenaries (total served), and 13,000 Native American allies.
However, one problem still stands and that is the fact that for many British, they did not want to attack their fellow man who were from the 13 Colonies. However, even then, the British could out last the USA. During the 5 years of fighting, the new Government was broke as the new states were not sending their money to congress. Robert Morris, a wealthy American, ended up funding the war but he couldn't do it forever. If the Americans and French didn't defeat the British at Yorktown, they would've lost because it was not possible to fund the Army. Not every soldier was being paid, but this couldn't last. Only the most patriotic Americans would keep fighting without pay.
Even if we assume that everything plays out mostly the same, Cornwallis would've escaped from Yorktown instead of being defeated. Cornwallis' defeat is what ended any chances of the rebellion being put down. His 9,000 troops would've been saved, and the British would play it off as a victory like they did centuries later at the Battle of Dunkirk. There might be a lull during the war (Henry Clinton would likely sit in New York), but there is no way that George Washington would attack New York. Such a battle would dash any chances of the Americans winning the war. The war will become a stalemate as the British draw up new plans and bring in new forces to fight against the Americans. Eventually the USA's new army will shrink in size as Washington is unable to pay his troops or they die off from sickness from the winter setting in. With the fresh new troops, the British could continue their attack in Spring and put pressure on them until they eventually cracked from lack of funds and supplies.
(Extra Credits. Watch all Parts)
http://www.encyclopedia.com/history...nd-maps/populations-great-britain-and-america
https://en.wikipedia.org/wiki/American_Revolutionary_War
https://web.archive.org/web/20130927073929/http://orbat.com/site/uk_orbats/files/6/The British Army 1775.pdf