20 hp Intek, valve guides moved.

Hi all, new to group. I have a 20 hp Intek and the valve guides moved. I am looking for a repair or is there a replacement head I can trust not to repeat this problem. Thanks in advance. Love this forum.

There is a guy on here that has a repair for them, and several people have had good luck with his method. Something else to check is the mounting surfaces for warpage. the tolerance is .003 out of flatness, and I found that most heads with this issue tend to be warped outside of spec by several thousands. I have had several that .010 was not unusual. The problem is caused by overheating of the head which allows the aluminum to expand at a different rate them the cast valve guides allowing them to loosen and then migrate.

Thanks for the info. I will check for flatness before tackling valve guides. I work in a machine shop, so I guess I could shave the heads if needed. Thanks again.

Heads were flat within .005. Lapped them in to under .003. Reassembled tonight and it runs great! I will know more after I run it awhile. Thanks again for the help.