Head. YX 140/149 RED TAG RACE Gas flowed 19 BHP

Head kit YX 140/150 Stage III RED TAG engine tune up kit 19 bhp

Now with TB piston

This head fits both YX 140 and YX 149

Full head kit assembled ready to bolt on.

What’s in the box?

• Fully gas flowed head
• Correct squish band for 56mm piston
• NBR cam shaft with sprocket 32T 2 bolt
• Race valve spring kit 40 psi with lift shims
• Valves 27 inlet 23 exhaust coated non polished
• 2 Angle valve seats
• Top set of gaskets
• 56mm high comp piston kit 13mm pin

Recommended carb to use

We recommend you don’t rely on the timing marks and set valve timing via LCA, they way it prevents valve damage and will give you the best performance. Reason is some engines have the crank sprocket pressed on not 100% correct.

You need a minim of 2mm piston to valve clearance 12 degrees before and after TDC on both valves, any less you will have piston to valve contact at higher revs resulting in a valve dropping.

Red/Blue TAG head 140/150

This head should be fitting by a professional, specialist tools required.

Valve clearances Inlet 3 thou Exhaust 5 thou

Head torque 12 ft-lb’s” Oil nuts and threads”

Cam timing don’t rely on OE marks as they can be wrong, dial cam in 105 degrees LCA both inlet and exhaust.

We recommend you change the cam chain and all 4 rubber components relevant to the cam chain tension, and only run mineral oil to prevent the rubbers going hard and breaking up.

Valve float caused by the above cam chain tension will result in exhaust valve making contact with piston.

Check piston to valve clearance at 12 Degrees before & after TDC you need a minimum of 2mm

Re check head torque after first heat cycle

Failure to do above can result in valves clipping piston and eventually bending or dropping valves.