Motorcycle Repair: 2005 Yamaha VStar 1100 Spark plu thread damaged, worse case scenario, thread chaser

Question
Do I have to remove the engine cilynder head to repair the spark plug thread? Based on information from the service manual I have to remove the motorcycle engine to access the clinder head.

Thanks
Ernesto

Answer
Ernesto,  you might want to try to find a thread chaser and see if you can clean up the threads, if they are just a little cross-threaded. If you can get a correct sized tap in the hole, pack the threads with axle grease, which will capture most of any shavings that may work loose or are removed from the tapping process. Have a good machine shop expert evaluate the situation, if possible.

If the threads are pulled loose and completely damaged, then the ideal situation for repair is to have the cylinder head removed. Heli-Coil or Time-Sert repair kits can often save the part from needing complete replacement.

In most cases, with big V motor bikes, you do have to remove the engine assy, in order to remove the cylinder heads, in a worse case scenario.

Bill Silver