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YEB-321 valve guide question
Posted: Tue Dec 09, 2014 5:06 pm
by ppalan
The valves on my YEB-321, especially the 1st, are getting noisy. They seem to be moving slightly in the valve guide channels. I have the metal guides. I have three questions: 1.) As I look at the guides, the part that actually rides in the channels seems to be divided into 2 halves. Is it possible to use a very thin blade to pry the halves apart ever so slightly to increase their size in order to take up some of the space in the channels? 2.) Is it possible to use the newer plastic guides directly or use them after some modification? 3.) Is it possible to fabricate guides? If so how would I go about this? I only have typical home tools. (no lathes, drill presses, etc.)
Thanks for any info.
Pete
Re: YEB-321 valve guide question
Posted: Tue Dec 09, 2014 6:19 pm
by Dan Schultz
Be warned. There are no more of those metals guides unless you are fortunate enough to turn up a parts horn. I had a few of these guides but sent the last one I know of on The Planet to a shop in California a while back. You might be able to expand the guide slightly as you mentioned.
Converting to late model guides??? Unless I'm mistaken... the deck height of the pistons are different and there is not enough space to incorporate late model plastic guides without trimming a amount equal to the thickness of the new guide off the top of the piston. Adding the index hole for the plastic guide is doable but will take some 'creative' machine work and the ability to actually see inside the piston bore and casing. I know my borescopes won't see around the casing knuckles.
Re: YEB-321 valve guide question
Posted: Tue Dec 09, 2014 6:46 pm
by Jose the tuba player
TubaTinker wrote:Be warned. There are no more of those metals guides unless you are fortunate enough to turn up a parts horn.
Damn it !
so what metal are these guides made of?
i need to go grab my Yamaha 103 from the middle school in order to measure the guides to be able to either sketch it out on solidworks and import it into master cam in order to generate the G-code to run it on the Haas cnc machine we have in the machine shop, or 3d print some.
Re: YEB-321 valve guide question
Posted: Tue Dec 09, 2014 10:47 pm
by J.c. Sherman
The Allied catalog does (did) have instructions for the conversion to the newer guides (including new stems). But the early guides, if long enough, do expand slightly when tightened/pried.