Just been removing the last 4 valves from my 30 heads and i have noticed that one of the valve guides has dropped right down, have tried pushing it with my finger and its solid, i think it must have been like this while i have been using the bike!

Here are some photo's i took:





So my questions, what could have caused this to happen? How close was i to dropping a valve and writing the engine off? And most importantly how do i go about fixing this? Had a quick look through the haynes manual and it is saying valve guide removal should be left to a honda dealership, so i guess its going to be quite costly.

Any help with this would be greatly apreciated,
Kieran.

Just buy replacement heads,

Surely an engine remanufacturing place would be able to relocate the guide.
Guides are a tight interference fit - could the head have been worked on/rebuilt previously?
If the guide was rattling loose you'd see damage however, even if the guide was loose the valve wouldn't drop but would still prob ruin the head!

Pip

Depending on whether or not it's an intake or exhaust valve, you're still looking at under a tenner each for the guide, but if the valve has been damaged they're £20 something intake and about £40 for an exhaust. So by the time you've had an engine builder with the right kit extract the guide and replace it, you could probably buy a secondhand head. There are loads of heads on evilbay for around £50. Good or not, who knows....

Thanks for the replies, im not sure if the head has been worked on previously, from looking at the state of the piston tops and combustion chamber it hasnt due to all of the carbon build up on there. However there are some marks to the top of the valve guide that you cant make out in the pictures so something has come in contact with it.

The valve was undamaged same with the springs, i will take a closer look tomorow to double check, but it looks like this will be cheaper and easier just to replace the head. I will go down to my local bike garage and ask if there are any local places who could relocate the guide, but what baffling me is how it moved in the first place?!

Maybe its was just made wrong, i'm guessing its sticking out more the other end or has it just been cut down? Its a wonder the valve was shutting!
Cheers
Ian

Yea its sticking out further the other end, i did try to get a photo but i couldnt get a good shot with the next one to compare it with. Scary to think what could have happened if the valve had stuck open!

Bit of an update on this. I went to my local bike place who are pretty good with this sort of thing and they said i could probably persuade it into its proper position with alot of heat and force, but ive got hold of a second hand head as it will probably work out cheaper than buying a torch or whatever id need to heat it up enough to get it back in the proper postition. Plus any other tools that id need to get it at the right height just means its not viable when ive sourced a replacement for a good price.

Of course, if you did want to see if you can sort it, with a spare head fitted you have the opportunity to try without fear of what would happen if you get it wrong... You never know, it might be easier than you think!

Put it in the oven for an hour or so, and using brass drift give it hit with hammer.