Gasket Sealant: yes or no?

[RedBolide]

I'm rebuilding the engine on my GS850. I bought a tube of gasket sealant for reassembly. However, the store clerk told me that it isn't necessary, and that he had been rebuilding engines without sealant and hadn't had any issues. Would you recommend using gasket sealant?

 

[Big T]

no sealant is needed

 

[Nessism]

The answer depends on the application. Open up your factory Suzuki service manual and use that as your guide. The manual tells you were sealer is mandatory. On the crankcase halves for example and around certain stud threads. As far as applying gasket goop on top of gaskets, that's generally not necessary if you are using factory Suzuki gaskets (the best available). If you are cheaping out and purchasing aftermarket gaskets then the answer may not be so easy. The valve cover should not be gasket gooped on the head side for sure. The other gaskets should not be gooped if you ever plan to ever take them apart again, however a light skim coat on the base gasket and or oil pan isn't the worst thing in the world, particularly if someone scratches up the sealer surfaces during old gasket removal. Threebond 1184 is the modern standard sealer for crankcase halves. Gasketsinch or 1184 on critical gaskets.

 

[limeex2]

The answer depends on the application. Open up your factory Suzuki service manual and use that as your guide. The manual tells you were sealer is mandatory. On the crankcase halves for example and around certain stud threads. As far as applying gasket goop on top of gaskets, that's generally not necessary if you are using factory Suzuki gaskets (the best available). If you are cheaping out and purchasing aftermarket gaskets then the answer may not be so easy. The valve cover should not be gasket gooped on the head side for sure. The other gaskets should not be gooped if you ever plan to ever take them apart again, however a light skim coat on the base gasket and or oil pan isn't the worst thing in the world, particularly if someone scratches up the sealer surfaces during old gasket removal. Threebond 1184 is the modern standard sealer for crankcase halves. Gasketsinch or 1184 on critical gaskets.

Exactly! It also works well to hold them in place if your working alone. Use VERY sparingly. I recently took apart one of my old GS's. I had used Yamaha brand gasket sealer, and under the gasket, which was not leaking, the sealant was not leaking, pliable and easy to remove. It was Yamaha's version and I believe it is Yamabond #4. Yamaha has very good chemicals.

 

[bonanzadave]

https://www.aircraftspruce.com/pages...ezturnlube.php

EZ Turn is a specialty lubricant/sealant used for fuel and oil line valves & is resistant to high temps. Especially effective where high octane fuels and aromatics are present. EZ Turn is also extremely efficient as a gasket paste & anti- seize agent. EZ Turn will not gum, crack or dry out. Each shipment is independently tested. Excellent for tapered plug valves, aircraft engine manufacturing, and marine applications. EZ Turn is the functional equivalent of fuel lube. 1 Lb. can
​

 

[Nessism]

Exactly! works well to hold them in place if your working alone. Use VERY sparingly. I recently took apart one of my old GS's. I had used Yamaha brand gasket sealer, and under the gasket, which was not leaking, the sealant was still pliable. I believe Yamaha's version is Yamabond #4. Yamaha has very good chemicals

What part number Threebond sealer corresponds to Yamabond #4? Yamaha does not make sealers, they just rebrand Threebond.

 

[limeex2]

Not sure of p/n but #4 is for use with gaskets, #5 is for use with no gaskets. That's good to know, Yamaha stuff is probably more expensive?, and Threebond is probably more readily available.

 

[Grimly]

I'm rebuilding the engine on my GS850. I bought a tube of gasket sealant for reassembly. However, the store clerk told me that it isn't necessary, and that he had been rebuilding engines without sealant and hadn't had any issues. Would you recommend using gasket sealant?
View attachment 49037

I doubt very much the store guy has been rebuilding GS850 engines for years, or any GS engines, for that matter.
The one area where every GS850 engine leaks (there are others, but not guaranteed) is around the left front on the base gasket, where there's a weird O-ring around an oil passage. It's a total pain in the arse to do a rebuild, with good quality gaskets and find the leak re-appears. It takes time, but it comes back. Every single GS 850 from the factory leaked there, if enough miles had passed.
Bitter experience taught me to give the base gasket a smear of Hylomar top and bottom around that area.
All the other leaks are generally nuisances, but can be easily fixed by removal / replacement of the offending part with a new gasket. The base gasket, head gasket, and case joint are special - you need to get them right on assembly.

 

[Nessism]

I doubt very much the store guy has been rebuilding GS850 engines for years, or any GS engines, for that matter.
The one area where every GS850 engine leaks (there are others, but not guaranteed) is around the left front on the base gasket, where there's a weird O-ring around an oil passage. It's a total pain in the arse to do a rebuild, with good quality gaskets and find the leak re-appears. It takes time, but it comes back. Every single GS 850 from the factory leaked there, if enough miles had passed.
Bitter experience taught me to give the base gasket a smear of Hylomar top and bottom around that area.
All the other leaks are generally nuisances, but can be easily fixed by removal / replacement of the offending part with a new gasket. The base gasket, head gasket, and case joint are special - you need to get them right on assembly.

The gasket area around that teardrop shaped O-ring is very thin. You can coat that thing with whatever you want and it's not going to do much if oil is going past that O-ring. Pretty sure those O-rings are on the rear studs though, not the front.

One thing that is listed in the manual but many GS guys don't ever do is torque the head. Even on the forum here we chatter about adjusting valves but never torquing the head.

 

[Grimly]

Brainfart on the position of the O-ring, but the certainty of the front left leak is a fact.
Another certainty, is that any one I've coated hasn't leaked.

 

[RedBolide]

I doubt very much the store guy has been rebuilding GS850 engines for years, or any GS engines, for that matter.
The one area where every GS850 engine leaks (there are others, but not guaranteed) is around the left front on the base gasket, where there's a weird O-ring around an oil passage. It's a total pain in the arse to do a rebuild, with good quality gaskets and find the leak re-appears. It takes time, but it comes back. Every single GS 850 from the factory leaked there, if enough miles had passed.
Bitter experience taught me to give the base gasket a smear of Hylomar top and bottom around that area.
All the other leaks are generally nuisances, but can be easily fixed by removal / replacement of the offending part with a new gasket. The base gasket, head gasket, and case joint are special - you need to get them right on assembly.

I'll be sure to do that then. Don't want any trouble later on. Thanks so much for the response (and all other responses for that matter). It's been super helpful!

 

[bobtail84]

When ever I fit new gaskets I use Wellseal. http://www.wellseal.co.uk/
It's easy to apply using a small artists paint brush and less messy than most other silicon type sealers.
I should imagine that you can buy it in the USA if not its easy enough to find on eBay.

HTH

Jeff

 

[davebgs850l]

OK you are from the usa go to Napa and buy the aircraft grade gasket sealer. I use it all the time never have had an issue. Only use on paper gaskets it will seal the gasket and never will leak and if you tear down the gasket will release from the substrate and not tear and cleans off very easy with brake clean just spray and wipe only get the stuff from Napa best I've found yet. I'm pretty sure its made by permatex.