By almost a 4-to-1 margin, federal workers voting in a Washington Post poll say that they would not come to work for Uncle Sam if they had it all to do over again.

Last week in this space we asked readers to vote on how they felt about Reagan administration plans to "reform" the way federal workers are paid, promoted, fired and retired.

As of late Friday afternoon we had received about 28,000 responses. Thanks! We love you! You made your point! Please don't send anymore! We're still counting and will give you further updates next week.

Meanwhile, based on just over 9,000 returns tabulated so far, this is how the vote is going:

Employes are overwhelming opposed to the administration plan to raise the age of retirement on full benefits from 55 to 65. Many people wrote in comments. Most said it is unfair for the government to change rules for current employes.

The vote, so far, is split over the proposed administration changes that would make performance, rather than seniority, the determining factor in who gets in-grade pay raises and in deciding who gets fired during layoffs.

By a slim margin, voters said they favor giving more weight to performance and less to seniority if they thought the performance appraisal system would be run fairly.

But in the very next question, the voters said they do not believe such a system could or would be run fairly.

If Reagan administration officials take the poll results to heart--and they have made inquiries about how the vote is going--they may decide they have a serious employe morale problem on their hands.

One most lopsided result (almost 8 to 1) was in response to the question whether voters feel this administration is treating them better or worse than the Carter administration. The majority said things are worse now.

The vast majority of the votes tabulated so far have come from people who identified themselves as federal workers. People working for virtually every area of the government responded, including the CIA and the Supreme Court. Some identified themselves as retired government employes and a few hundred people said they did not work for the government.

Here are the questions, and the vote breakdown as of late Friday:

* Regardless of how it affects you personally, do you think it is fair to make government workers work until age 65 to draw full benefits? Yes--782; No--7,704, with 25 voting "undecided."

* Would you support or oppose a system that ranks performance over seniority if you thought that performance appraisals would be made fairly? Support--4,304; Oppose--4,114, and 26 undecided.

* Do you think such a system would work in your office.? Yes--8,421; No--1,217.

* Do you feel this administration is better or worse than the Carter administration in its treatment of federal workers? Better--884; Worse--6,679; About the same--174.

* If you had it to do over again, would you go to work for the government? Yes--1,741; No--6,494.

Here are some of the comments voters attached to their ballots:

"Many of us entered federal service when President Kennedy was in office asking for the 'best and the brightest' to join him, feel we have a contract with the government. Apparently political expediency has made it legal to break this bond. . . There isn't an ounce of difference between President Carter and President Reagan. Both see federal employes as 'bastards and bums.' They kept President Kennedy's two 'b's, but changed the words. They have also succeeded in selling this concept to the American public and to Congress. . . "--From an IRS worker.

"How would you like to be flying at peak traffic time knowing that a good portion of the air traffic controllers were over 60?. . . C.S. stands for civil slave. It's time for a change, but the biggest changes need to be made at the top, not at the bottom. It's time that the big wigs stopped using federal employes as a smoke screen on America (outside the beltway) and clean up their act too.!"--An air traffic controller in Virginia.

More comments, and a vote count update, next week.