removing/installing valve guides

[bk305]

has anyone had luck replacing their valve guides on their 305's? i've got 2 intakes coming soon from ohio cycle and want to replace them myself on my 1963 cb77. i've checked most posts for any clues but so far i haven't run across anyone doing this. my repair manual simply says to put the head in the oven at 175 deg. and press the old out and the new in? ( in the first place, i can just see me doing this in my wife's oven!!)- ha anyhow... the manual also state that the new guides need to be reamed - is this really necessary? ( won't they come with a finished diamension? )-

[LOUD MOUSE]

I've been involved/worked on these engines for a really long time. (1962/2007) and have only found 2 valve guides that needed replacing. Both had broken tops. I have not to date found a warn guide be it intake or exhaust. What reason do you have to want to replace the guides in the head you have? . ...........................lm

has anyone had luck replacing their valve guides on their 305's? i've got 2 intakes coming soon from ohio cycle and want to replace them myself on my 1963 cb77. i've checked most posts for any clues but so far i haven't run across anyone doing this. my repair manual simply says to put the head in the oven at 175 deg. and press the old out and the new in? ( in the first place, i can just see me doing this in my wife's oven!!)- ha anyhow... the manual also state that the new guides need to be reamed - is this really necessary? ( won't they come with a finished diamension? )-

[bk305]

hi LM- i while back i replaced all the valves with new after market ones- when i ran the engine, both intake valves snapped at the top recessed keeper area. the bent valve shafts sorta distorted the guides and nicked the top of the guides. i had to " reform" them to allow me to reuse the original valves. to make a long story shorter... the head and new replacements were reground for the rebuild the first time. when i replaced the original non-ground intake valves i lapped them in hoping that it would be ok only to be disappointed later on with bad compression/ leaking into one carb. so... while it is apart again i thought i would replace the 2 guides and get another grind/check making sure it is right!- thanks for your help-bk

[LOUD MOUSE]

I suspect that your choice of AM valves started a profile of disaster. Good luck in the future. ................lm

hi LM- i while back i replaced all the valves with new after market ones- when i ran the engine, both intake valves snapped at the top recessed keeper area. the bent valve shafts sorta distorted the guides and nicked the top of the guides. i had to " reform" them to allow me to reuse the original valves. to make a long story shorter... the head and new replacements were reground for the rebuild the first time. when i replaced the original non-ground intake valves i lapped them in hoping that it would be ok only to be disappointed later on with bad compression/ leaking into one carb. so... while it is apart again i thought i would replace the 2 guides and get another grind/check making sure it is right!- thanks for your help-bk

[davomoto]

I have replaced valve guides on 50cc and 70cc Honda motors. They do indeed need to be reamed to fit the valves. I was able to borrow the ream from my local Honda dealer. If you don't have an in like this, consider having a local machine shop perform this service for you. As you have already learned, a few pennies saved now, can cost a lot in the future. Or, THE BITTERNESS OF POOR QUALITY REMAINS LONG AFTER THE SWEETNESS OF LOW PRICE IS FORGOTTEN.

davomoto