Advanced Machining Services, advmachining.com wants to thank you for taking the time to visit us. By specializing in MX bikes and ATV’s we provide our customers with a high degree of precision and professionalism in the trade and services we provide.

A 2-stroke top end rebuild generally consists of a new piston and rings. With the newer 4-strokes you have to consider all the moving parts above the piston, in the valve train. Keep this in mind when you do your top end, we will clean and inspect the valve train and reassemble with new valve stem seals for as little as $55.00 for the 4-valve heads.

The ugly truth is that most all new 4-stroke heads the valves have about a 15-20 hour service life. The majority of people don’t want to hear this. This is a full race, high rpm, bouncing off the rev. limiter application. For the casual trail rider this can be extended to 30-40 hours without catastrophic loss, about the same amount of hours the piston and rings will hold up.

The reason for the valve failure is a combination of this. The Titanium valves wear through their coating and the seats start to cut into them. Once you have to adjust the intake valves more than two times the valves are shot. If you keep running the machine at this time what happens is the valves become (tight) which means if you were to check the valve lash you would find no clearance. The reason for this is the valve has worn; meaning the valve no longer is in contact with the seat. At this time you will have noticed that hard starts are prevalent. You would have to be pushed and bump started to get running. When the valve no longer contacts the seat it has no way to disperse the heat. At this point the valve overheats because the seat can no longer wick away the heat (no valve to seat contact). And this valve overheating is one of the reasons for the valve to separate causing catastrophic failure.

You don’t want this. To rebuild the engine after this might equal the machines worth.

At the Motorama show at the Farm Show Building in Harrisburg, PA Feb 21-22 2009 We had on display a 2006 KX250F head, that was a bone stock head, never thouched, that sucked a valve. The reason for this is failure was that; the head was pushed beyond its valves service life. Don’t let this expensive lesson happen to you.

Advanced Machining Services home page. A vast array of OEM and aftermarket parts for your MX and ATV machines. Head kits, Cylinder kits, Engine kits, seats and guides replaced, cams, valves and spring kits, multi angle valve jobs, oversized valves installed, porting, big bore head mods., cylinder boring/honing, big bore kits. Advanced Machining Services, engine rebuilds, crank replacement, transmission repair. Box it up and ship it.

Advanced Machining Services LLC, 23 years engine building.

We provide kits that fit stock components for MX and ATV's with Race Tech Gold Valves, springs, and many other custom performance parts.

Fork and Shock oil change/rebuild, Revalve and spring service

Services for Showa, KYB, & WB

Services for Shox, Axis, Elka, Fox, & Works Performance

Factory Connection Parts & Service