Can I use paper gasket material for valve cover?

[jsmith24]

I have a rider with a 16.5 horse Briggs and Stratton, I/C, OHV. I took the valve cover off to adjust the valve lash, and spent five times as long to scrape gray RTV off the head and valve cover. I made a gasket from paper gasket material (plain gray stuff) - will that work or should I plan on getting some permatex ultra gray? I'd rather not, as I tend to adjust the lash once a year, or at least check it, and that RTV is no joke.

Thanks!

Jack

 

[StarTech]

From Service Bulletin 746.



It is to note that on OHV engine the rocker clearance should be adjust to the minimum clearance to extend time between adjustment periods as the valve train will wear and increase the rocker clearances.

Also note when applying RTV the rocker cover screws are only install finger tight for the first 12-24 hrs. Also you are not to start the engine during this time as the oil will prevent the RTV from curing properly. Once the initial curing time has pass then the screws are torqued to 65 in-lbs.

 

[jsmith24]

From Service Bulletin 746.

View attachment 70732

It is to note that on OHV engine the rocker clearance should be adjust to the minimum clearance to extend time between adjustment periods as the valve train will wear and increase the rocker clearances.

Also note when applying RTV the rocker cover screws are only install finger tight for the first 12-24 hrs. Also you are not to start the engine during this time as the oil will prevent the RTV from curing properly. Once the initial curing time has pass then the screws are torqued to 65 in-lbs.

That is absolutely perfect! Thank you the information, especially for including what appears to be info directly from a service manual. Are Briggs service manuals available for the public, whether free or for purchase?

Thank you again!

 

[kbowley]

You can download a service manualHere. Adjusting the valves every year is overkill, but if it brings you peace of mind, then it's fine. The recommended interval is every 200 to 300 hours. I agree that Permatex is a pain to clean but rarely leaks if installed properly. I use a flat plastic razor held vertically to the surface, and that works well. I use this Permatex style applicator and it works great. To apply it correctly, apply a bead around the edge of the cover, then install it with the bolts just snug enough to start to flatten the bead. Let it set for 8+ hours and then torque the 3/8 bolts to about 60-70 in lbs. / 5-6 lbs. ft.

 

[jsmith24]

You can download a service manualHere. Adjusting the valves every year is overkill, but if it brings you peace of mind, then it's fine. The recommended interval is every 200 to 300 hours. I agree that Permatex is a pain to clean but rarely leaks if installed properly. I use a flat plastic razor held vertically to the surface, and that works well. I use this Permatex style applicator and it works great. To apply it correctly, apply a bead around the edge of the cover, then install it with the bolts just snug enough to start to flatten the bead. Let it set for 8+ hours and then torque the 3/8 bolts to about 60-80 in lbs. / 5-7 lbs. ft.

Thanks for the links. I didn't know the service interval so I was going by the "it probably won't hurt" theory. I also wasn't aware of plastic razor blades, so I was out there with an old credit card. Those aren't very rigid so it took quite a while. Last year (the first year I owned this used mower) I used the Permatex Ultra Gray, which sealed great but was hard to remove.

Thanks again, it helped a lot!

 

[kbowley]

Thanks for the links. I didn't know the service interval so I was going by the "it probably won't hurt" theory. I also wasn't aware of plastic razor blades, so I was out there with an old credit card. Those aren't very rigid so it took quite a while. Last year (the first year I owned this used mower) I used the Permatex Ultra Gray, which sealed great but was hard to remove.

Thanks again, it helped a lot!

My pleasure.

 

[grumpyunk]

I think a wipe of silicone oil on the sealing surface may make the RTV release easier. I know it works when using filled epoxy such as where you have damaged threads on the brake retainer bolts on a rider transaxle. There were some threads, but not quite enough to feel secure. Once the epoxy set up, the bolt unscrewed readily.
i am trying to decide whether it should be wiped, as in with a paper towel dampened with the oil, to the cover or to the top of the head. It should seal properly, but then peel off relatively easily.
tom

 

[jsmith24]

I think a wipe of silicone oil on the sealing surface may make the RTV release easier. I know it works when using filled epoxy such as where you have damaged threads on the brake retainer bolts on a rider transaxle. There were some threads, but not quite enough to feel secure. Once the epoxy set up, the bolt unscrewed readily.
i am trying to decide whether it should be wiped, as in with a paper towel dampened with the oil, to the cover or to the top of the head. It should seal properly, but then peel off relatively easily.
tom

Hey Tom, interesting idea, and sounds like it would work. I've already sealed it up, but I'll keep it in mind for other things. I think I'll try it on a blown engine I have first just to see. I don't have silicone oil handy, per se, but I do have some silicone spray lube I use for rubber seals. We will see what happens!

Thanks for the idea!

 

[grumpyunk]

Hey Tom, interesting idea, and sounds like it would work. I've already sealed it up, but I'll keep it in mind for other things. I think I'll try it on a blown engine I have first just to see. I don't have silicone oil handy, per se, but I do have some silicone spray lube I use for rubber seals. We will see what happens!

Thanks for the idea!

If you want to try the spray vs purchasing some silicone oil, I'd spray a bit on a paper towel and wipe it onto the surface. You don't want it wet and oily, but just a sheen. Kind of like using oil on a cookie sheet, just get is barely wetted, wipe with a damp towel, etc.
tom

 

[jsmith24]

If you want to try the spray vs purchasing some silicone oil, I'd spray a bit on a paper towel and wipe it onto the surface. You don't want it wet and oily, but just a sheen. Kind of like using oil on a cookie sheet, just get is barely wetted, wipe with a damp towel, etc.
tom

Thanks, will do!