It's the sound that gets you. In this era of social responsibility and decibel limits we forget how evocative, how awe-inspiring and, let's face it, just how loud the Grand Prix bikes of racing's golden era were.
From the eerie howl of a Honda 250 Four accelerating out of a corner, the crackling bad temper of a Suzuki RG500 just out of its power band and the flat drone of a Ducati F1-R to the musical but almost painfully loud three-cylinder Suzuki TR750, old bikes speak to you in a way modern machines aren't allowed to.
It's not the only reason for the success of Historic Racing but it is one of them. The sound track helps summon up an era when racing was still fun and there were practically no limits to what you could do in search of speed, when 125cc bikes had five cylinders and revved harder than today's Formula 1 cars.
Killarney's annual International Historic race meeting, a leg of the national Springbok Series, is the one day of the year when racers can rattle the windows and spit as much blue two-stroke smoke as they want, because these bikes, as politically incorrect as they may be, are protected by their age and iconic status.
Thus, at the weekend we saw - and heard! - six times World champion Jim Redman on the Honda 250, Dave Petersen re-united with the same Suzuki RG500 he rode in Grands Prix in 1986 and motorcycle journo Sir Alan Cathcart reliving the good old days on Macau GP winner Mick Grant's Suzuki XR1000 endurance racer - the ancestor of the GSX-R750 - while Grant himself went back to his racing roots on a 1959 McIntyre AJS 7R and Manx GP hero Jimmy Guthrie showed us he was still as smooth as ever on a 500cc Manx Norton.
But for sheer presence there was nothing to touch Les van Breda (father of current National contender Graeme) on his Suzuki TR750, one of only about 19 made and practically identical to the one Barry Sheene crashed at the 1975 Daytona 500 at more than 270km/h.
You could always tell exactly where it was on the circuit - just by listening! - as it accelerated out of corners hard enough to make modern litre-class bikes look slow.
Then it was the turn of the local heroes of the Regional Classic motorcycle series - and this was no parade, there were both pride and points at stake.
Pole position went to veteran racer Danie Maritz on a 1985 Suzuki GSX-R750 he'd built for the occasion to take on David Bolding's all-conquering Suzuki Katana "Big Bertha".
However, Maritz's 1min23.922 qualifying lap was only 0.319sec quicker than the Katana, setting the stage for an epic confrontation. But it was John Kosterman on a 1981 Honda CB1100RC who got the best start in Saturday's Race 1, leading lap one from British visitor Alan Walker (Ducati 888), Bolding and Maritz.
Walker took the lead on lap two and held off the locals for two laps, only to be blitzed by both Suzukis on lap five. The rest of the race was vintage racing in every sense of the word as Maritz and Bolding swopped places at least once a lap, never more than a bike-length apart.
But it was Maritz who was 0.387sec in front when it mattered, with Walker 18sec further back, followed by Marius Botha (Suzuki GSX-R750) and Kosterman.
RACE 2
Maritz and Bolding set an even hotter pace in Sunday's Race 2, pulling away from the pack within the first lap and treating the crowd to a display of 1980's style Superbike racing, wrestling the bikes into the corners and passing each other on the brakes wherever they could.
Back-markers intervened on the final two laps, however, helping Maritz to a 1.851sec victory margin with Botha nearly a minute in arrears after Walker crashed out of third in turn four on lap six.
Botha, however was only 2.2sec ahead of Tony Jones (1983 Cagiva 650 Alazzurra) after another race-long dice between the kamikaze braking of the Cagiva rider and the Gixer's superior straight-line performance.
Kosterman was fifth and Andrew Mearns (out of retirement for the occasion aboard Jacques Lerm's Suzuki GS1000) sixth after Marco Sanders (1981 Ducati 600 Pantah) slid off in turn two trying to stay ahead of the big Suzuki.
There was close racing throughout the field, with even the last two finishers, Jacques Lerm (1980 Honda CBX1000) and Casey Wolters (Yamaha RZ350) coming home only two seconds apart after, to quote a grinning Wolters, "I kept him honest" for seven laps.