The Minstermen have won more points on their travels than they have collected at KitKat Crescent this season and McEwan feels that dissenting voices in the crowd, as well as the club's troubled playing surface, have contributed to that statistic.
McEwan berated one complaining Main Stand supporter during the first half of Tuesday night's 2-1 home victory over Northwich Victoria.
Play-off chasing City were also booed off the pitch in some areas of the ground at the interval having fallen behind to Northwich's only shot of the first half.
McEwan is counting on a more supportive following during trips to Aldershot and Cambridge United in the next four days and has called for home spectators to show a more united front during the final five crucial KitKat Crescent Conference clashes of the season against St Albans (March 17), Stevenage (March 27), Gravesend (March 31), Rushden (April 10) and Oxford (April 28).
He said: "We've done well away from home this season and it will be a bit of a relief not to hear the odd negative voice in the crowd which, I must say, I can't believe.
"This club was heading for the Conference North when I came here. Over the last two years, we have played some relatively decent football but I'm afraid that's not good enough for one or two people.
"I don't know what we have got to do. If we were where Halifax are now then I might understand but that worries me as well because, you never know, we might be there next year or the year after and what happens then? Does that make me a bad manager?
"We've got a lot of young footballers and we are progressing. Around 99 per cent of our supporters are absolutely fantastic but there are the odd one or two that like to moan. I don't want that to grow into three or four, nine or ten or even more because people need to understand this is Conference football being played on a cabbage patch.
"I'm sure Aldershot's pitch will be better than ours because my back garden is. I apologise to people who heard me lose my temper on Tuesday night. I was out of order but I was absolutely disgusted by the comments that came out of the stand.
"So, please get behind the team win, lose or draw because we have got to be united for the rest of the season."
McEwan has also warned his side to beware of an "inconsistent" Aldershot side who have enjoyed victories over fellow play-off contenders Gravesend, Stevenage and Burton (twice) this season but lost to lowly Tamworth on Tuesday night.
Winger Martyn Woolford has pressed his claims for a starting place after his match-winning goal as a substitute against Northwich and a starring role in Wednesday's 3-3 reserve draw against Scunthorpe.
McEwan said: "We put Martyn on at a vital stage of the game on Tuesday night and he did the business. He came on and made an impact.
"He's clever, has a football brain and can see things on the pitch but he won't develop if people shout at him."
Tomorrow's squads
City (probable): Evans, Craddock, Kovacs, McGurk, Peat, Convery, Bishop, Panther, Bowey, Farrell, Donaldson. Subs: O'Donnell, Elvins, Woolford, Parslow, Lloyd.
Aldershot (probable): Bull, Smith, Day, Charles, Barnard, Williams, Molesley, Newman, Beckford, Grant, Dixon. Subs: Winfield, Wells, Hudson, Pritchard, Hylton.
Referee: Roger East (Wiltshire).
KICK-OFF: 3pm.
Source: www.yorknews.co.uk