Recently did a ring job on a GCV160. Spent more time cleaning the gasket maker off the crankcase & valve cover than the rebuild itself. I have adjusted Honda valves before so I knew the clean-up job would be tedious. Since this engine was given to me, and because I am keeping it as a back-up, I decided to cut my own gasket for the valve cover & skip the goo as a test. I used basic Fel-Pro 3157 Rubber Fiber bought off Amazon. Well, so far, so good. I put the engine on a spare lawn mower deck & ran it for about 20 minutes each day for 2 days (no grass to mow in the winter here.) No leaks. If this continues, I will be very happy with this result vs. razor-scraping Hondabond, etc. Just thought I'd pass it along. Time will tell if it continues to seal longer term. Be glad to explain how I created the template for the final gasket if anyone is interested.
#2
Boobala
easy way to remove most any gasket material/ sealant is one of these nylon wheels with a die-grinder or drill-motor...
When I did a ring job last year, I just tossed the valve cover and replaced it with the cast aluminum one from a GSV190 that uses a gasket to seal. It would be interesting to see if the GSV190 gasket would work on the stamped valve cover since its about $20 to get the valve cover, gasket, and longer bolts.
Gasket is rubberised cork & works fine on the tin covers if they have not been bent & twisted during removal. Most will be damaged.
Silicons dissolve in petrol so you use a scotchbrite pad as previously mentioned wetted with petrol .
I keep a drum with old stale or water damaged fuel drained out of customers engines and if possible immerse parts needing silicon removed in it for a few days.
After this the stuff just rubs off with a finger .
#5
shurguywutt
I don't even clean mine if it still looks to be in good shape. I just put a small bead of silicone on top of the old stuff and seal it back up, finger tighten it. I then like to let it sit for 24 hours before I torque the bolts.
#6
StarTech
One problem foreseen in using a gasket for the cylinder barrel to oil pan. This affects end play of components that mounts in both pieces. Too much end play can cause problems.
As for RTV clean up yes is work to clean it up even with abrasive discs you got make you clean up the parts afterwards. The discs I use are less likely throw off parts of itself. With the one shown I would advise wearing safety glasses. I wear them most times working any thing that could throw materials into my face especially those crimped wire brushes. Just last week I had one those wires that went up my nose and was fun to get out. I also have already spent over $200 having a metal fragment removed from my right eye this year where I failed to put on the safety glasses. I was lucky as it just burn my cornea and stuck on the surface. It could have been a lot worst.
Make sure no oil is present when using RTV or Honda bond. As resealing with RTV I use Permatex surface prep and accelerator spray. Put parts back together with the retaining screws finger tight when using RTV and wait a least 12 hrs then torque to final torque specs.
Most techs and DIYers simply pry these metal rocker covers off but that usually damages them. There is a much better way loosening these cover before removing them and that is to sheer them off or at sheer loosen them. Ever since I learned the method I haven't had a damage rocker cover to try to straighten other those where the retaining screws were over tighten to begin with.
I don't even clean mine if it still looks to be in good shape. I just put a small bead of silicone on top of the old stuff and seal it back up, finger tighten it. I then like to let it sit for 24 hours before I torque the bolts.
I don't even clean mine if it still looks to be in good shape. I just put a small bead of silicone on top of the old stuff and seal it back up, finger tighten it. I then like to let it sit for 24 hours before I torque the bolts.
Thats the difference in approach between some one who can just do it again if it fails and some one else who has to give warranty on what they do.
The only place silicon goes on anything in my workshop is 2 stroke crankcases .
#8
StarTech
Bert, you find that both Briggs and Kohler have switched over to RTV for rocker covers. Kohler has for year used RTV to seal crankcases at times and other times used gaskets. The Honda GCV160 here used RTV on both the rocker cover and crankcase halves. Many Hydro and other transaxles use RTV. Either that or you are making a lot custom gaskets.
#9
Scrubcadet10
My rule of thumb is if it comes from the factory with RTV, it goes back on with RTV. If it comes with a gasket, it goes back with a gasket. except for kohler courage valve covers which i use permatex ultra black on to prevent future issues.
Things that get pulled of regularly like rocker coves get gaskets regardless of weather they came with one or not .
I charged fixed rates for servicing ( note not repairing ) so do it once do it right is the go
I buy my gasket material in 4' x 8' sheets where possible as it is dirt cheap that way.
Hylomar on the cover side & bentonite grease on the engine side and that gasket will be fine for 20 years if not overtightened .
I don't do hydros I send them out to the expert so they come back purged & ready to fit for less than the wholesale price of a rebuild kit
About the only boxes that I pull apart are manual ones where the F-N-R shift gear is gone and yes they get silicon as it should be 20 more years before I have to pull them apart again.
The Honda push mower owners think I am a god as the other shops all charge them $ 50 to $ 70 for a new rocker cover with every service
From me they get a once off $ 10 for $ 20 for the gasket .
Most of the courage singles that I service regularly do not leak oil from the rocker cover and run the same cover gasket for at least 3 services.
When I could not get any I used some old nitrile / cork that I bought decades ago and it worked a treat so am considering to using it excluseivly once the current stock of original Kohler ones are used up
I had a standing order for 5 of them + 1 closure plate gasket every month
#11
Hammermechanicman
I don't use RTV silocone on 2 stroke crankcases. I use threebond 1184. It is more resistant to gasoline than silocones. Same as Hondabond and Yamabond. I don't use it on valve covers because it makes them too hard to remove. I have about a dozen different gasket makers and sealers and the most used are the threebond 1184 and permatex the right stuff. I have seen case seal fail on stihl saws with silocone.
Just thought I'd update since I started this thread almost 2 years ago. I have used a gasket vs. silicon on three GCV190's or 160's since then and none are leaking. The valve covers on them were in pretty good shape (not badly bent) so that's probably a big reason that it has worked for me.
#13
shurguywutt
I had a leak on a GCV190 pressure washer, I swore it was the valve cover gasket which was a bear to get off, turns out that annoyingly enough, it was a dumb little camshaft O-ring right below the gasket. Failed from the factory with under 20 hours of use.
