First Dirt Bike

k01

k01

PR Elite
1969+Yamaha+L5T+Trailmaster+100+road+test+01.jpg
1969+Yamaha+L5T+Trailmaster+100+road+test+02.jpg

My first real dirt bike, it came with a high pipe, skid plate and knobby tires. Electric start in 1969 too, so nothing so new about that today. I had a Buco helmet like the one on the rack in the photo. Helmet was from Sears and the bike was new from Glenn Jordan's Motor Sports 888-8720.
 
jeffro667

jeffro667

PR Addict
71 JT1 mini enduro, another rotary valve! Seems like these were the first bike for a bunch of people. I raced mine for a year in the junior class, no mini class then, I was always racing against 100's and 125's.
20200320_174200.jpg
 
Last edited by a moderator:
k01

k01

PR Elite
MarctheSharc said:
Why did we go way from the rotary valve ??
Performance or pollution....????
I think it was pollution right, because some of the early rotary's I rode all RIPPED.
Click to expand...
Look at the massively wide cases on the 100 Trailmaster. With the extra windings for the starter on one side and the carb on the other, at least it seemed balanced. jeffro667 would know, the ATK 250 Rotax had, I believe, a long running rotary valve engine?
 
k01

k01

PR Elite
jeffro667 said:
71 JT1 mini enduro, another rotary valve! Seems like these were the first bike for a bunch of people. I raced mine for a year in the junior class, no mini class then, I was always racing against 100's and 125's.
Click to expand...
Are those the stock bars on that little JT1?
 
k01

k01

PR Elite
jeffro667 said:
Nope, you know how I rolled with bars back in the day, lol! There was a lot not stock on that bike by the time we were done.
Click to expand...
At the time kind of wish they had those when I was a kid. Lol In a mere couple of years the mini had evolved. Did all of your add-ons come by way of mail order?
 
jeffro667

jeffro667

PR Addict
k01 said:
At the time kind of wish they had those when I was a kid. Lol In a mere couple of years the mini had evolved. Did all of your add-ons come by way of mail order?
Click to expand...
No mail order, the stuff we bought came from The Scooter Shop in Chillicothe. The porting and rotary valve mods were done at home, with help from magazine articles.
 
MarctheSharc

MarctheSharc

PR Founding Father
jeffro667 said:
No mail order, the stuff we bought came from The Scooter Shop in Chillicothe. The porting and rotary valve mods were done at home, with help from magazine articles.
Click to expand...
We were new, enthusiastic and into a fledgling sport.
I tried to find anything I could.
My dad did a magazine port job on a YZ 80.
It was sooo blazing Fast when we tested it down the street !!!
Then, at the track, I was struggling. The thing had ZERO bottom end and I couldn't get it to go around the moto track to save my life.
Got a great start only to fade back quickly.
Dumbfounded, we started to ask others what they thought of the port specs.
It may have been George that finally saw what we had done and explained it.
Comes to find out ..... it was a full on Pro Kid flat track setup .......Not good for a goon at Smith Rd.
We had to toss the cylinder .... we learned.
 
k01

k01

PR Elite
MarctheSharc said:
We were new, enthusiastic and into a fledgling sport.
I tried to find anything I could.
My dad did a magazine port job on a YZ 80.
It was sooo blazing Fast when we tested it down the street !!!
Then, at the track, I was struggling. The thing had ZERO bottom end and I couldn't get it to go around the moto track to save my life.
Got a great start only to fade back quickly.
Dumbfounded, we started to ask others what they thought of the port specs.
It may have been George that finally saw what we had done and explained it.
Comes to find out ..... it was a full on Pro Kid flat track setup .......Not good for a goon at Smith Rd.
We had to toss the cylinder .... we learned.
Click to expand...
Hold it wide open kid!
 
You must log in or register to reply here.
Top