Fourcroy's 411 Bultaco Service Center
Overhaul

 

Forks
Shocks  
Carburation  
Ignition
Exhaust
Transmission
Bultaco ID  

Parts

Mobley's Bultaco

Speed and Sport

 

 

Oil - Amounts


Fuel Golden
Spectro Oil
50:1 ratio
Forks 210 ml 30 wt.
Primary 300 ml 30 wt.
Transmission 600 ml 70-90 wt.

Torque Chart:

Engine     Suspension  
Engine Mounting Bolts 35 ft/lb Front/Rear Axel Nuts 30 ft/lb
Front Sprocket 90 ft/lb Swing Arm 75 ft/lb
Flywheels & Clutch Hub 75 ft/lb Fork Caps 50 ft/lb
Seal Retainer 5 ft/lb Axel Clamp 6 ft/lb

Cylinder Head
   • 4 Studs
   •
2 Bolts


18 ft/lb 12 ft/lb

Triple Shaft Nut 30 ft/lb
    Top Triple Clamp Bolt 15 ft/lb

 

 

 

 

 


PPG Paint Codes
Bultaco Blue Grabber Blue
DBU 2230
Bultaco Silver Crystal Silver Metalic
DAR 34926
Bultaco Red Torch Red
DAR 74013
Bultaco Gray Grigo Chiaro
DCC35982

 

Parts
Air Filter UNI
# NU-3204ST
$27 @ AMS

Fork Seals
35 x 47 x 10.5

Try Honda 350

$15
Rear Sprocket
125 Pursang 46 teeth
250 Pursang 48 teeth
Sprocket Specialist  

Front Sprocket
125 Pursang 11 teeth
250 Pursang 12 teeth

   

520 Chain
11/46 = ~106 links
12/48 = ~110 links

   

Rear Brake Shoes
140mm Diameter

WPS
EBC 14-833G

$27
Primary Chain for 125 Pursang    
Primary Chain for 250 Pursang    

 

Problems:

Q: Engine sounds like marbles rattling around when it idles, but goes away with rpm's
A: Check the primary side flywheel (Lynn Mobley)

Q: Fork Caps leak oil out the breather hole
A: Cut plastic disks and wedge them in the fork springs a couple of inches
    below the top. (Lynn Mobley) or... plug the hole.

Timing:

2.8mm BTDC (.110")

 

 

Resources:

Basic Motoplat Testing

http://www.yankeetwin.com/motoplat.html

Bultaco Terry Cable Listings

http://www.terrycable.com/CABLE%20LISTINGS/bultaco_cable_listing.htm

Mobley's Bultaco Great for Bultaco Parts

Speed and Sport Great for Bultaco Parts

http://www.bultacoparts.com/

Bultaco ID

Replacing Worn Vintage Fork Legs

 

Suspension Forum

http://www.dirtrider.net/forums3/forumdisplay.php?s=&forumid=29

 

http://www.off-road.com/dirtbike/machines/vintageguide/

http://www.off-road.com/dirtbike/machines/vintageguide/

 

How Shocks Work

http://power-mods.bizhosting.com/shocks.html

 

Vintage Bultaco Racing

http://www.mazman.com/bikes/bultaco/1-bul.htm

 

Suspension/forks

http://www.doctordanger.com/projects/projPS_frame.htm

 

Respoke Wheels

http://www.heaven-vmx.com/TW_May74_Spoke_Wheel_Rebuild.htm

 

 

Works Performance

http://www.worksperformance.com

 

Bultaco Pursang Center

http://www.bultacopursang.com

 

Track & Trail Super Test: Bultaco 250 1974

http://www.heaven-vmx.com/Bultaco_Pomeroy_Replica.htm