Any ATK aficionado's here? NEED INFO

GIwasB4
Profile picture for user GIwasB4
Posts
2585
Joined
7/24/2008
Location
Beverly Hills, CA US
GIwasB4
Edited Date/Time 9/7/2017 10:32pm
So this is propped up against a fence. (for a long time I would surmise) Is it worth going back to retrieve? Are parts available? I realize the pics are less than desirable but it's what I have to work with. Looks to be complete. ATK406?





Red seat with "USA" on sides
Blue frame
2 stroke
WP Suspension






|
AHRMA361
Profile picture for user AHRMA361
Posts
2472
Joined
4/1/2008
Location
NE, OH US
Fantasy
180th
AHRMA361 9/6/2017 12:50pm
9/6/2017 12:50pm
Post a picture of the engine. The 406 uses a reed valve mounted conventionally. The 250's were a rotary valve design. Both made by Rotax in Austria and parts are generally available for the engines.

It appears it has the anti-torque feature for the chain drive still. Does it have the countershaft mounted brake disc on it as well?
GIwasB4
Profile picture for user GIwasB4
Posts
2585
Joined
7/24/2008
Location
Beverly Hills, CA US
GIwasB4 9/6/2017 3:44pm
9/6/2017 3:44pm
That's all I have for pics. It does have the countershaft brake. Looks like it was rolled up behind the building and left. It's a bit of an adventure to get that close without trespassing. Was hoping someone could identify as is. Working on closer inspection and tracking down the owner, thanks!
MaxPower
Profile picture for user MaxPower
Posts
2647
Joined
8/15/2006
Location
NJ US
MaxPower 9/6/2017 4:12pm
9/6/2017 4:12pm
I think I have a rear brake caliper and rotor and rear sprocket and tank for that bike
GIwasB4
Profile picture for user GIwasB4
Posts
2585
Joined
7/24/2008
Location
Beverly Hills, CA US
GIwasB4 9/6/2017 5:02pm
9/6/2017 5:02pm
MaxPower wrote:
I think I have a rear brake caliper and rotor and rear sprocket and tank for that bike
Hey Max, can you tell if I'm correct that it's a 406? maybe 1988? I'd be interested in parts if we can match up model and year.

The Shop

See All »
SmokinJoe439 9/6/2017 8:48pm
9/6/2017 8:48pm Edited Date/Time 9/6/2017 8:54pm
My friend owned a 406 from then brand new if you ask him about it. Says the only good things about it was the engine and the anti torque chain guide. Frame cracks bad suspension the counter shaft brake would heat up. He even had one of those atk lq (liquid cooled) 250's.

It brings up the story of when he bought a new 406 piston and the box was opened by the shop from the bottom. Dropped it right outside the shop door dinging the crown after just getting it new. They wouldn't take it back no refund they was $200 for a piston in the early 90's. I have seen said piston they are pretty big.
I don't mention atk's around him they are the devil.
trials guy
Profile picture for user trials guy
Posts
6
Joined
9/14/2016
Location
Lake Hopatcong, NJ US
trials guy 9/7/2017 5:47am
9/7/2017 5:47am
I have several ATK's, My guess is a 1988 ATK. Aluminum swingarm tells me that.
Looks like air intake is curved. The 406 snorkel or intake has a flat spot facing the rear tire. Hard to tell from picture.
Just like the post above look at the intake, Center cyl with reed block 406. 250 is rotary valve on the left side of bike.
So my guess is a 1988 ATK 250?
Anything can be brought back from the dead, however the 1988 rear brake master cyl and actuating rod are very hard to find. The 1989 ATK's went to a rear facing rear brake pedal.
Way more 406 than 250 out there. I prefer the 250 engine with lightened flywheel.
MaxPower
Profile picture for user MaxPower
Posts
2647
Joined
8/15/2006
Location
NJ US
MaxPower 9/7/2017 6:26am
9/7/2017 6:26am
Need a better side view. From what I see I'm thinking you are right about being a 88 406.
I had a 250 project that I sold to fund another project. The person that bought it did a great job restoring it
Sidecar
Profile picture for user Sidecar
Posts
1725
Joined
1/29/2015
Location
GB
Sidecar 9/7/2017 1:49pm
9/7/2017 1:49pm
If nothing else those WP forks are worth a little, especially with clamps, brake and wheel.
AHRMA361
Profile picture for user AHRMA361
Posts
2472
Joined
4/1/2008
Location
NE, OH US
Fantasy
180th
AHRMA361 9/7/2017 4:02pm
9/7/2017 4:02pm
trials guy wrote:
I have several ATK's, My guess is a 1988 ATK. Aluminum swingarm tells me that. Looks like air intake is curved. The 406 snorkel or intake...
I have several ATK's, My guess is a 1988 ATK. Aluminum swingarm tells me that.
Looks like air intake is curved. The 406 snorkel or intake has a flat spot facing the rear tire. Hard to tell from picture.
Just like the post above look at the intake, Center cyl with reed block 406. 250 is rotary valve on the left side of bike.
So my guess is a 1988 ATK 250?
Anything can be brought back from the dead, however the 1988 rear brake master cyl and actuating rod are very hard to find. The 1989 ATK's went to a rear facing rear brake pedal.
Way more 406 than 250 out there. I prefer the 250 engine with lightened flywheel.
I looked closer at the pics and yes it looks like a curved intake for the rotary valve. Also, the cylinder fins are the same as a 250. 406 fins did not have the gaps on the side fins like the 250. see pic
So, it is most likely a 1988 ATK 250.

http://www.americandirtbike.com/88-250.gif

GIwasB4
Profile picture for user GIwasB4
Posts
2585
Joined
7/24/2008
Location
Beverly Hills, CA US
GIwasB4 9/7/2017 4:42pm
9/7/2017 4:42pm
AHRMA361 wrote:
I looked closer at the pics and yes it looks like a curved intake for the rotary valve. Also, the cylinder fins are the same as...
I looked closer at the pics and yes it looks like a curved intake for the rotary valve. Also, the cylinder fins are the same as a 250. 406 fins did not have the gaps on the side fins like the 250. see pic
So, it is most likely a 1988 ATK 250.

http://www.americandirtbike.com/88-250.gif

I'm thinking your correct. Working on getting back and hopefully haul it home.
That pic you supplied is a good looking bike. Never gave ATK a thought until I saw this one, I'm excited.
MaxPower
Profile picture for user MaxPower
Posts
2647
Joined
8/15/2006
Location
NJ US
MaxPower 9/7/2017 10:32pm
9/7/2017 10:32pm
I could be wrong, I was thinking it was a 406 by the size of the head. I had a 250. Another pic will clear it up. AHRMA361 sounds like he may be right too.

Post a reply to: Any ATK aficionado's here? NEED INFO