Recently had the MD for regular service . These machines have no oil filter and oil change intervals are at 50 hrs. Noticed the head gasket was weeping out oil . I had posted on twitter about the repair at the 236 hr mark . Received a few favorites and questions about if it was covered under warranty or why I was doing the repair .We it's like this . The dealer is a good 3.5 hrs. away and I enjoy my job so much and organised enough that I'm willing to do the warranty repairs myself . Under the direction of Bill at Veseys they are usually fairly easy repairs . Believe me it has it's perks most of the time .
Not quit blown head gasket but soon .
Really like the spring clip set up on the exhaust .
Made removal very easy .
You can leave this part of exhaust manifold on .
Carburetor was just as easy to remove leaving all the cables attached .
I wrapped a rag around it to keep dirt out till assembly .
Next turn engine till you see that both rocker arms have play . Then remove the pin that holds them in place . Easy design on the Yamaha engine . No clips etc. the valve covers is what holds the pin in place .
Lay the parts out in such a way that you can assemble them back in the same location .
I have a heavy flat bar that is used with med emery cloth to evenly remove gasket material . I noticed the cylinder was ever so slightly of in the blown gasket area . I kept removing material in 8 different directions till it all looked flush .
Head looked pretty good . To make sure it's flat and square I use my bench plate with a large piece of emery cloth and work the head against it in a figure eight pattern . Ready for assembly .
You can see the guides in valve cover that hold the rocker arm pin in place. So simple .
Assemble in reverse order . I did torque the head down carefully to 15 ft.lbs. first then to 36 ft. lbs. Always torque in a cross bolt pattern .
I did notice that the head shield has tabs to hold the valve cover gasket in place . Also there is one longer bolt for the dip stick tube side on valve cover . Took it for a run and it worked great . No leaks.1.5 to 2 hrs . taking your time and keeping things clean and organized. Over all not a bad job and can be done in the machine .