Toroidal Head

This is a stock head that has been re-machined to unlock the true potential of the Blaster engine. Arguably the easiest and cheapest upgrade you can do on the Blaster that yields greater horsepower gains than any other engine upgrade. This upgrade can take a stock Blaster from 18 HP to the mid 30's. Best of all this performance upgrade doesn't require any jetting changes to your existing carburetor. Simply bolt on and ride! Fits all years (88-06).
 
Technical Specifications: 
Combustion Chamber Type: Toroidal
Combustion Chamber Size: 20cc
Squish Angle / Area: 11 Deg 50%
Optimum Bore Size: 66mm for Stock Option or 72mm for BBK Option
Finish Type: Vapor Honed
 
FAQ's
Difference between Toroidal and HEMI chambers? Toroidal makes better mid-range torque and self-limits over-revs. The HEMI makes better peak power and RPM.
 
Will I need to use race fuel? No, you can use standard 93 high octane pump gas.
 
What head gasket will work with this? Please use a new Yamaha OEM head gasket (p/n: 2XJ-11181-00-00) to achieve the proper squish.
 
Will this require jetting changes to my carburetor? No, since this modification only changes the burn of the air/fuel mixture and not the flow. No jetting changes are needed.
 
What bore sizes will this work with? Any of the bores sizes that fall between the option you select (stock or BBK - Big Bore Kit). Although best performance will be achieved with a stock 66mm bore for the stock option or 72mm for the BBK option.
 
There's some pitting in the chamber of the head I received. This is normal and will not affect the performance of your head. The voids are from the original casting process of the stock head.
 
Can you make custom heads to my specific needs? Yes we can alter any of the technical specifications listed above to your request.
 
Do I need to run a spacer plate under the cylinder for the stroker option? No, our heads are machined so that the additional piston clearance needed is in the head and not the cylinder. 
 
Note: The listing pictures are for reference only. Since we re-machine used stock heads some will look slightly different than others as far as dirt and paint. However the machine work will be identical to what is shown in the pictures. We do offer a bead blasting service for our heads as an option. Please see our store where you can add this service to your shopping cart.