B&S 17.5 OHV - oil on engine - gaskets?

[dmarion]

Good afternoon everyone,

I'm a new member (my name is David), and I would appreciate some opinions about my mower. It seemed as if it was losing some power last season after cutting for 45 minutes or so and then trying to go up a hill in my yard. There's a good bit of oil around the engine block (always has had some and occasionally I'll clean it). Anyway it hasn't been cleaned in a while and I was wondering if it appears to any of you as if it might have a blown head gasket or valve cover gasket. I've attached a few pics. Thanks in advance for your assistance.

David

 

[mechanic mark]

Valve cover gasket needs to be replaced. Clean engine first by hand, do not use water, remove blower housing first, red cover topside & clean everything, removing all dirt & debris with scraper, soft bristle brush, etc., piece of coat hanger for nooks & crannies knocking everything loose & then use shop vac to pick it up. Check air filter, fuel filter, & spark plugs for replacement. Adjust valves with engine cold then install new valve cover gasket & change oil & filter after engine warmup. Let us know how she goes, thanks.

Yes water will corrode electrical components making them inoperable, fail to work. Get a spray bottle of simple green & roll of shop towels & wipe it down, stay away from electrical parts.

 

[dmarion]

Mark - thanks for the info and advice. One more question if you don't mind. You suggest to not use water - is that general advice or would you suspect that somehow it would get into the valve cover, etc? I was actually thinking of loading the mower on a trailer and taking it to a self serve car wash to clean the engine and frame with some engine de-greaser (the oil is everywhere). I understand the magneto would need to dry out and I'd need to wrap up the carb/intake to keep water out that way. Are there any other dangers in doing that? Thanks again for your help and advice.

 

[pugaltitude]

Pressure wash will not cause any problems and is the quickest and easiest way to do it.
Use a TFR type chemical or soap to remove oil.
Just make sure it all dries out quickly.
I wouldnt fit a gasket to the rocker as it would probably leak again.
Briggs have changed it to silicone sealer which seals it.

 

[ILENGINE]

Pressure wash will not cause any problems and is the quickest and easiest way to do it.
Use a TFR type chemical or soap to remove oil.
Just make sure it all dries out quickly.
I wouldnt fit a gasket to the rocker as it would probably leak again.
Briggs have changed it to silicone sealer which seals it.

Can't use the sealant on the valve covers with the embossed mounting surface. It will not have the proper clamping force to prevent future leaks. But if you have the flat mounting surface, you can use either the gasket or sealant.

 

[bertsmobile1]

Degreaser & a pressure washer.
Remove the cowl defore youwash as it will need cleaning underneath .
Run the washer quickly over the engine repeatedly rather than cncentrating on a single spot for a lomg time.
Dry the engine best way you can and give the electrical connections some WD 40 or similar while dissconnecting & reconnecting them.
Marks advice is worth heeding as watre gets caught inside the plugs and will corrode the wires.

 

[pugaltitude]

Can't use the sealant on the valve covers with the embossed mounting surface. It will not have the proper clamping force to prevent future leaks. But if you have the flat mounting surface, you can use either the gasket or sealant.

As far as the Briggs service bulletin 746 it states that you can use sealant or gasket on the embossed rockers which I have never had a problem with sealing.

 

[ILENGINE]

As far as the Briggs service bulletin 746 it states that you can use sealant or gasket on the embossed rockers which I have never had a problem with sealing.

Your rights that is what it says. We were told at an update seminar not to use sealant on the embossed covers because it wouldn't seal properly. It also says you can't use gaskets with the flat mating surface covers. But the first OHV covers with gaskets were flat without embossing.

 

[dmarion]

Thanks again everyone - I appreciate all the advice.

I got the top shroud off today and it looks like I may be able to get a lot of the buildup off just with a medium bristle plastic brush. I have some simple green and some gunk engine degreaser if I need it, but will wait to see. Meanwhile I'm trying to figure out how to get the cylinder shroud off - there's so much buildup I'm not sure where all the bolts are. I also got a replacement B&S rocker cover gasket and some gasket shellac just in case.

One other question - would you recommend putting the cylinder shroud back on when I'm done? Does it help the cooling to any discernable extent or is it there to prevent clippings from coming into contact with the cylinder?

 

[bertsmobile1]

One bolt on each and they lock into each outher
This is exactly why Mark keeps on posting links to the parts books and why you should have one.

As for replacing the covers
Yes.

Just done a $ 695 repair to an engine run without them on, not pretty and this was mechanical damage.
The engine has low compresion and will be lucky to make it through two more seasons.
B & S did not put them there to frustrate you or bump up the price of the engine.