No!
1. McLain's bike was too far back.
2. According to the bike expert and actual rider, McClain, he said motor sound on the dictabelt is from a three wheeled bike.
3. Sheriff Bill Decker saying "hold everything secure" in the exact place where the shots supposedly occurred. Yet Decker was known to have said "hold everything secure" about a minute after the real shots in Dealey Plaza.
And this is only a small part of the refuted dictabelt evidence.
Steve Barber as seen below is the actual expert on the dictabelt evidence and Steve's initial interest came from when he heard the "hold everything secure" from a recording of the dictabelt and these words were proven to have come way after Dealey Plaza! Go Steve, Go!

The following passages come from Reclaiming History and McClain the actual man behind the supposed Dealey Plaza recording, strongly refutes this deceptive "audio evidence".
McLain gave his reasons for believing it wasn’t his mike. Among them was the
fact, he said, that the sound of the motorcycle clearly indicated the cycle was trav¬
eling way too fast to have been in the motorcade; though he had turned his siren
on, there were no siren sounds from the motorcycle with the stuck microphone;
and when the sound of sirens did appear, they seemed to be passing a stationary
unit.RHVB
The importance of McLain being ordered to be on channel 2 and remember¬
ing many of the channel 2 transmissions during the motorcade cannot be
overemphasized. It literally, by itself, destroys the HSCA’s acoustic conclusion of
a fourth shot—at least if the committee is basing it on McLain being the cyclist
with the open microphone.
The second point McLain wanted to make, after repeating that he was “sure”
the stuck mike was not his, was that the sound on the channel 1 cycle was “not the
sound” of his cycle, a two-wheeler that day, explaining that he had ridden “both
two- and three-wheelers” on the force, and “this was a three-wheeler. It’s all
together a different sound.RHVB
What brought them crashing down to earth was when the smoke-and-mirrors conclusion of the
HSCA was exposed as such in 1982 by a panel of twelve physicists and scientists under the aegis of
the National Research Council. Hailing from places like MIT, the Lawrence Berkeley Laboratory at
the University of California, and the Bell Telephone Laboratory in New Jersey, and headed by
Harvard professor Norman Ramsey, the panel of experts analyzed the subject Dictabelt and heard the
same impulse sounds that the two Queens professors did. The only problem was that the "sounds" the
Queens professors heard occurred "one minute after the assassination," when the presidential
limousine was long gone down the Stemmons Freeway on its way to Parkland Hospital. RHVB
JohnM