*** 1977 atc 90 custom bandito replica build ***

[1979atc]

Here is the inspiration for that Build.

Attachment 227938

Going to be a neat build, can't wait to see it done. What kind of tank you have on that bike?

[bkvette3]

Wow- just beautiful.

[Joseph Farrow]

Okay figured I would finish up on this build.
For the final part we have the MOTOR.

It started out life as a stock 89cc 1977 ATC90 motor.
It is now a 180cc Helm & Son Alcohol Motor. For anyone who has not experienced one of these motors your are in for a susprise. They are unbelieveably fast and full of tork.
When you grab ahold of the pull start you better have it on the compression stroke and tell yourself it is going to start....if not you may lose some skin in the palm of your hand. lol

To get to 180cc form 89cc you have to do some major mods.
Start with a stroker crank. This motor has a Helm & Son 61mm Long Rod with 14mm pin. (90). The bore is 61.75mm using a 14:1 Forged Venolia Alcohol Piston. It runs inside a Helm & Son Star Burst Cylinder. With the Long Rod stroker you have to use a 6mm Aluminum spacer plate.





Up top it has a Ported Head with lightend and polished valves. HD springs and titanium keepers with lightend rocker arms.
Cam is a BAPP Streaker II. Intake is a PK with 24mm Mikuni Carb with Sudco Pumper Kit.



To handle the extra HP the clutch has been modified. It has HD plates and spring as well as a Reinforcement Ring. If you raced these bikes back in the day you know you can blow a clutch at high RPM's. The Ring keeps this from happening.



On the other side it has the Hi/Low gear box removed for a Quick Change Sprocket Assembly. This allows for easy counter sprocket removal.
Notice the Extra Large BAPP Pull Start Handle.



To relieve internal pressure it has several vents including a BAPP dip stick. To help add life to the motor a Haden Oil Cooler keeps the oil cool.



To make it sound good and to keep with the Helm & Son theme Judson used a super rare Helm & Son Stinger Exhaust Pipe.




Well this just about completes this build. Stay tuned for more to come. Other projects in the works.
I'll leave you with one parting shot......

Me sitting on the Bike. "Bandito Joe" (Notice Judson made me take my shoes off before I could set on it. lol)

[Jwheeler]

You guy's out did yourself on this build. Awesome trike, now lets get it in the sand turn & burn!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Socaldaddy]

Do you have more history on shop etc. what happend to owners etc .

[shortline10]

Beautiful build !!!!