Leakdown test Failure! (basegasket)HELP!!

:crying:Just tried to leak test my motor. Everything else seem to be fine except for my base gasket right above the reeds on both of them. I sprayed soapy water on everything and this seems to be the only leaks. The gasket had a small ribbon of sealer just in these two areas, and nowhere else.The leak is only coming from the opposite side of the gasket (case side) as the sealant was only on one side. My ADA instructions say to torque the girldle bolts to 23ft lbs for final torque which is 6lbs short of what is recommended by yamaha. I retorqued them up to 29ft lbs but with no success. Should I pull the cylinder back of and use some type of sealant on this gasket? Is it possible I have the sealant on the wrong side,(gasket upside down)? I lined it up with the dow pins and it went on great I placed the sealant part cylinder side up. Does this matter? Please help, any help would be great. Thanks. Would it be possible if oil got on the gasket from intallation to let air pass between the two surfaces? Just a thought.
 
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WaveDemon

Not Dead - Notable Member
Location
Hell, Florida
I think that's supposed to be a dry gasket. I've never used sealant on it. take it back apart and check to see that the surfaces are straight with a straight edge.
 
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Looks straight with the straight edge. It may have a slight imperfection but the gasket is definetly thicker than any discrepancy there is between the two surfaces. I have never had to use sealant on any of my other builds before either, of course these were all two stroke single cylinder dirtbike engines. Not much different though.
 
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I spray every gasket I use with Coppercoat. They might not need it but I haven't had any problems with sealing. It might not be the coppercoat that seals but never hurts to be safe.

You can NOT reuse a gasket after it has been installed with coppercoat because it sticks good and they are harder to clean off but who cares the results of an air leak is harder to cleanup than the coppercoat.
 
take it back apart and make sure the are no little 'curls' on the case edges.

it doesnt hurt to put a THIN coat of 1211 on a NEW base gasket.

i do 35 lbs on the girdle bolts. dome people do more.
 

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
If your ADA head girdle kit is fairly new (better studs) up the torque to at least 38 ft-lbs.
I have run as much as 45 ft-lbs before on these newer ADA studs! I use no sealer on stock OEM base gaskets.
 
I think ADA's directions state 18ftlb 1st round to 23ftlb second round... is extra torque really going to make things better?

yes. 23 ftlbs is what you would do your head bolts at... and theyre tiny compared to the cylinder base bolts. oem calls for 29 on those... and thats with the head on the casting. sandwiching the cylinders logically would call for more torque.
 

Ericfox

Do it twice?That's DooDoo
I will have to check... I see your point... but I think the ADA directions call for 23 ftlbs on both girdle and head bolts for final.... I think you make a good point though, and I may torque my girdle bolts a bit more.
 
I will have to check... I see your point... but I think the ADA directions call for 23 ftlbs on both girdle and head bolts for final.... I think you make a good point though, and I may torque my girdle bolts a bit more.

ignore ada's torque specs for the girdle hardware. theyre just too low.
 
Thanks guy's. Checked the cases for burs and such and none were found put a tiny bit of sealant on as not to squish any into the ports, an upped my torque. I retested it and it sealed good, but found another leak in front where my case has been filled with epoxy for porting behind the stator Now I got to figure out the best way to go about fixing this. What a wonderfull weekend:banghead:any suggestions?
 
I keep reading about this Devcon stuff, but I don't see which one it is anywhere.They have several different style's/types. Can any one tell me a part# for this stuff. Or if there is something better?
 
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