B & S 6.5HP Intek Valve Stem Seal

[ralphj1]

I'm working on my Scotts (Murray) mower with a vertical shaft B & S Intek 121682 0122 E1990203FA. I fixed a hot start problem by cleaning out all the crud that had built up in the cooling fins. I fixed an oil leak problem by replacing the pushrod guide plate gasket. I was seeing some blue smoke briefly during a cold start so I replaced the intake valve stem seal. The old seal 692044 sat under the bottom of the intake valve spring. The new seal 795440 is relocated to the intake chamber between the working end of the intake valve and the top of the valve guide. It was necessary to remove the cylinder head to install the new valve seal. With the new seal the engine now smokes all the time. I removed the cylinder head again to look at the seal. The seal was fully seated over the valve guide. There was a small puddle oil in the cylinder. I popped out the seal and looked at it under a low power microscope. Other than pry marks on the metal shell, the seal looks okay. It seems like a better design with a garter type spring at the top of the seal. Does anyone have experience with the new seal? Any suggestions as to what to try next? The old seal (NOS?) doesn't seem to be available anywhere.

[Deere2me]

I personally haven't run into one lately, but I gotta tell ya, I ain't never seen an umbrella type valve stem seal installed in the intake port!
Did the seal come with one of them famous B&S instruction sheetlets sayin' that's where it goes? I dunno.

[RoyM]

That is a new one on me too. Why was it necessary to install the seal this way?

[ralphj1]

Here's a link to a scan of the instructions:
http://i1243.photobucket.com/albums/gg5 ... f0a0af.jpg

This engine has been in service about 15 years. There seems to be some valve guide wear as I can wiggle the valve a tiny bit side-to-side. If someone knows of a source for the old seal 692044 please let me know. Parts websites redirect you to the new part 795440. The backside of the old seal I removed is dinged up. It may work if I apply a thin layer of black RTV between the seal and pushrod guide plate. Another solution is this new head on Ebay:
http://www.ebay.com/itm/Briggs-Stratton ... 4ad71b8c94

[Deere2me]

Here's a link to a scan of the instructions:
http://i1243.photobucket.com/albums/gg5 ... f0a0af.jpg

This engine has been in service about 15 years. There seems to be some valve guide wear as I can wiggle the valve a tiny bit side-to-side. If someone knows of a source for the old seal 692044 please let me know. Parts websites redirect you to the new part 795440. The backside of the old seal I removed is dinged up. It may work if I apply a thin layer of black RTV between the seal and pushrod guide plate. Another solution is this new head on Ebay:
http://www.ebay.com/itm/Briggs-Stratton ... 4ad71b8c94

Thanks for the info! That's a new one fer me.
If you clean/degrease everything up with some carb spray, you can prolly seal up the old stem seal. I would use something like a red Hi temp rtv or ideally yamabond or hondabond rtv crap.

[RoyM]

A little side play is necessary on an air cooled engine, without it the valve will seize in the guide when hot. You still have not explained why you installed the seal under the valve head.

[Deere2me]

A little side play is necessary on an air cooled engine, without it the valve will seize in the guide when hot. You still have not explained why you installed the seal under the valve head.

Yeah, actually, he did!

[KE4AVB]

Being a 99 model I would do a compression and leakdown tests on the engine too especially since the engine has ran hot due lack of air flow.

[kcomp1863]

I realize this thread is 7 months old, but I had the same question and concerns as ralphj1. Since he had posted a link to the scan of the B & S instruction sheet for the new type stem seal, but still received so much "flak" for installing the seal, clearly in accordance with the instruction sheet, I contacted Briggs and Stratton technical support directly. I attached a copy of the instruction sheet ralphj1 had posted. This was tech support's answer:

Ken,

Thank you for your inquiry.

Please follow the instructions on the instruction sheet, in which MS10379 is correct. I have attached it again for your convenience. If you need further assistance, please contact a local dealer using the link below. Thanks!

SO, regardless of some of you other posters with past experience, who questioned the validity of ralphj1's post, the new seal DOES get installed INSIDE the intake port on the valve guide extension....end of story! Sometimes going directly to the source and getting the straight dope from "the horse's mouth", so to speak, will clear up any questions, concerns, or confusion. This info is posted mostly for any others who come across this thread with the same question.

Thanks,

Ken C.

[KE4AVB]

Ken, The OP was asking the same thing most us wondering about. Once we a copy of the instruction sheet we didn't question it but it is a lot different installation than what we normally see. At least now most us are aware of how the new part is installed. Personally I still don't see how that valve guide is going to be lubricated.

Hopefully we all learned from such open discussions. Things do change over time due to new items and improvements made by the manufacture with has a much larger R&D department than any of the field techs.