Valve Guide bushing resize

[KE4AVB]

Anyone know what is the minimum clearance I need for a .2460 exhaust valve stem? Briggs had me to install the 262001 bushing which normally fits the valves that go with it. In this case it doesn't fit so I got to purchase a new reamer as the .250 reamer leaves the valve fairly sloppy in the guide. The .004 overall clearance seems excessive but could be what the spec is as thing expand from the heating.

[KE4AVB]

So I take it that no one does valve guide replacement any more so I ordered a reamer that .0035 larger than the valve stem. I am thinking that .0025 is going to be too tight for an exhaust valve. Even Briggs, the manufacture, will not respond with an answer; just want us to guess at what is need. When I sent a request to Briggs, it said I would get a response back within 48 hrs.

[bgsengine]

yeah - I do very little, if any machining work any longer, as much as I might like to, it just isn't cost effective any more.. I might do it on a hobby engine or custom build, but I never do those either..

[RoyM]

Briggs does not give out the spec but do (or at least did) supply a go-no go tool. I have the tools for the engines up to 5 hp but haven't used them in years.

[KE4AVB]

That Go/No Go tool is useless in my opinion as I had valves hanging up on the valve seats and the tool still would not slip into the guides. Matter of fact the exhaust valve is hanging on the valve seat on the engine that I repairing currently and that Go/No Go still passes the guide.

Briggs like to sell the guides that we got to finish ream but if they will not give the needed spec it is self defeating the purpose of doing it the guide replacement is in the first place. They even sell the valve tools but I have found times that they are not even the right ones. Now I do make my own bushings for those engines that have the thin brass ones so I must use a size larger reamer for installation of those and then finish ream to correct size. The last 36" tube cost less than $8 where the valve guide from Briggs is 11.20 ea for 1" section.

That is like replacing the governor shaft bushing on these 5 hp engines. Briggs told in an email me to ream it to .250. Well that was definitely wrong as the .250 reamer will not even go in the worn out leaking bushing that I replace every so often. It the correct one it is a letter C (.242) reamer and .008 is a big difference.

I reckon the so called mechanics today are not even good part replacers as I have been seeing a lot of screw-ups lately. Apparently I have out lived my usefulness as I still actually repair the problem instead of just slapping on a new engine for a simple repairable failure.

[Walt 2002]

Well you are the last of a breed. I did repair but no longer do work.

Walt Conner

[KE4AVB]

Then I need to stop asking for help then and go the way of Lonesome George ....

[bgsengine]

Yeah its difficult to go by specs.. I actually never did for vale guides, Im old school and did it by feel... if they felt a bit too loose an there was an actual suspected valve issue, I'd re=do valve guides.. Always felt the briggs go-no-go was way too sloppy.. but in any case, I got no spec for them.. when I did valve guides, it was always "by feel" as to when I had em right.. never had a comeback either