Here another technical question

[KE4AVB]

Here is another technical that I probably will not get an answer to.

What size finish reamer do I need the exhaust valve guide on a Briggs 128702-0672-01 '96 model? It is not the 1/4" reamer that is the 1/4 valve guide tools kit as it is too big and the 6 mm I have is small than the valve stem. I got this one to replace the guide on as it is worn out. Don't want to destroy a $6 guide experimenting.

[bgsengine]

Here is another technical that I probably will not get an answer to.

What size finish reamer do I need the exhaust valve guide on a Briggs 128702-0672-01 '96 model? It is not the 1/4" reamer that is the 1/4 valve guide tools kit as it is too big and the 6 mm I have is small than the valve stem. I got this one to replace the guide on as it is worn out. Don't want to destroy a $6 guide experimenting.

Actually I seem to recall that valve guide tools kit was put together wrong, that or they got overly generous with clearance allowances - but I got a new kit back in 2010 and the finish reamer was quite a bit bigger than it seemed it should be, finally found my previously lost older (from the 1980's) reamer kit and had the correct finish reamer there. However it has actually been ages since I even bothered with re-bushing a valve guide nowadays - it was cheaper for them to buy a new lawnmower (or a new head set, or they had a used engine they put in themselves) so I can't recall the exact size.

Actually, kinda though you had already gotten a correctly sized finish reamer at some point? or was that for the 5/16 guides?

[KE4AVB]

My Serbia 1/4" reamer is actually 0.249 according to my digital caliper. The valve stem dia. I am working with is 0.243 new.

In the past the 1/4" valve guide set initial reamer was undersize for the after market bushings I was buying and I had go up 1/64" to install and then finish ream them with the 1/4". I now got a stock brass tubing for that purpose but this engine's bushing is a larger OD. Appears to be either bronze or a cast metal. I will need to order the bushing to determine what it made of as I don't one on hand. If I knew they were going to double the price since last June 2017, I would have ordered more.

In the past Briggs told to use the 1/4" reamer to do governor cross shaft bushing and they were wrong about as I had use a letter B (0.238) or a letter C (0.242) reamer to do that work.

Maybe I need to call McMasters in the morning to see what they have in 6 flute reamers that would be between the valve's 0.243 and the 1/4" (0.249) reamer.

As for the 5/16 valve guide set I got one but have never used it; just collecting dust.

[bgsengine]

Hmm sounds like one of those rare ones that have actual sintered metal replaceable bushings - IIRC they do not need finish reamed? Parts lookup shows the 63709 bushing but I have come across a rare few now and then that had replaceable sintered metal bushings - and only came across the correct part numbers in the OE Briggs parts lookups - the ARI lookups don't mention it correctly

Other possible to consider is does the block match the numbers on the blower housing? Many's the time Ive had them come in with a seemingly perfectly matching engine only to find the blower housing was not original (and thus the model-type-code were not correct to the engine)

[KE4AVB]

Knowing my luck I will need to clean it up after I drive it in since the engine is still mounted on the log splitter; otherwords, a field install. If I was pressing it in I would not be worried but it kinda hard to put the log splitter in my hydraulic press.

[KE4AVB]

As I figured after installing the guide the valve won't fit properly. I ordered a Cobalt reamer.

Closing thread...