Base gasket time..?
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Grand HDF Member
Joined: Aug 2008
Posts: 3,601
Likes: 9,915
From: Florida's gorgeous East coast
Base gasket time..?
That little bit of oil that has pooled on the top of the case appears to have originated from weeping base gasket. This is two days sitting in the garage after being wiped off. The motor is a ‘99 “ crate motor “ put in my ‘85 FXRS. It has 44,000 since a top end was done at 100,000.
I’m wondering if just re-torquing the head bolts might resolve this or am I going to have to go further..? Any experienced advice is appreciated.
Btw.. what’s best these days for gaskets..? Been a while since I bought them.
Road Warrior
Joined: May 2017
Posts: 1,347
Likes: 2,060
From: Phoenix
I don't think tightening the head bolts is going to fix it.
I think if you tighten them too much you run the risk of pulling the threads out of the cases. When the bike heats up the aluminum cylinders expand more than the steel bolts putting even more stress on the threads in the cases.
I think if you tighten them too much you run the risk of pulling the threads out of the cases. When the bike heats up the aluminum cylinders expand more than the steel bolts putting even more stress on the threads in the cases.
Stellar HDF Member
Joined: Aug 2012
Posts: 2,664
Likes: 184
From: Indiana, USA
IMO - Base Gasket Weep is a result of cold cylinder shrinkage resulting in slightly working the cylinder around the piston as the cylinder warms at startup. Paper base gaskets just do not holdup and once you torque head bolts and add the extra rotation it is not a good idea to add more rotation which will either stretch the stud or start pulling threads when engine reaches operating temperatures and head and cylinder are at their maximum thickness. (Coefficient of thermal expansion by material type)
I have had good luck with Genuine James Silicone Bead Base Gaskets. I believe the silicone bead provides the compliance to seal a cold engine and is soft enough to squish under normal operating temperatures.
Unfortunately you gotta pull the heads and cylinders to do it but in the end you get a peek at your cylinder hatching and new base & head gaskets. And the metal silicone bead base gaskets will not tear like the old paper gaskets at cold startup.
I have had good luck with Genuine James Silicone Bead Base Gaskets. I believe the silicone bead provides the compliance to seal a cold engine and is soft enough to squish under normal operating temperatures.
Unfortunately you gotta pull the heads and cylinders to do it but in the end you get a peek at your cylinder hatching and new base & head gaskets. And the metal silicone bead base gaskets will not tear like the old paper gaskets at cold startup.
Genuine JamesCylinder Base Gasket (.017 in. metal/silicone) - JGI-16777-94 for Select Harley-Davidson Motorcycles
Grand HDF Member
Joined: Apr 2007
Posts: 3,727
Likes: 3,071
From: Brighton, MI
I can't speak for any other gasket than the ones I am currently using. Cometic single layer steel (SLS) with a very light dusting of hylomar. Been doing it's job since top end was redone about 4 seasons ago. I would suggest you consider having the cylinder bases trued up as MoCo never trued them from the factory. That goes a long way to making a better seal.
Along with that and letting the cylinders warm up (grow in length) before driving off/loading up the engine.
Along with that and letting the cylinders warm up (grow in length) before driving off/loading up the engine.
HDF Community Team
Joined: Dec 2005
Posts: 5,421
Likes: 2,621
From: NC USA
All the factory base gaskets were defective though careful warmup would extend life, they all leak with factory gaskets.
The current production OEM gaskets are totally different and will not leak. The current valve cover gaskets are silicone and fit perfectly. All others are too thick and can cause cover leaks.
They will jump in here and swear they use this and that with no problems. I have used all types in past but found OEM are superior to any other. I've always put about 12k a year on mine, more if I do road trips. OEM holds up..
The current production OEM gaskets are totally different and will not leak. The current valve cover gaskets are silicone and fit perfectly. All others are too thick and can cause cover leaks.
They will jump in here and swear they use this and that with no problems. I have used all types in past but found OEM are superior to any other. I've always put about 12k a year on mine, more if I do road trips. OEM holds up..
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
Sometimes the base gaskets are so shot that you can re-torque the heads and convince yourself that you fixed it...but you haven't, leave them long enough and they disintegrate, the head bolts lose all their torque and you blow head gaskets.
A well-known MC brought an FXR to me once, because the head gasket blew, somebody (not me) had "rebuilt" the motor, put an EV27 in it and replaced all the rocker and head gaskets but not the original base gaskets, which. with 65K miles on them, were like oily cornflakes....I fixed the bike, they went to see the guy who "rebuilt" it....money changed hands...
A well-known MC brought an FXR to me once, because the head gasket blew, somebody (not me) had "rebuilt" the motor, put an EV27 in it and replaced all the rocker and head gaskets but not the original base gaskets, which. with 65K miles on them, were like oily cornflakes....I fixed the bike, they went to see the guy who "rebuilt" it....money changed hands...
Seasoned HDF Member
Joined: May 2008
Posts: 21,173
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From: South Carolina
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Cruiser
Joined: Aug 2020
Posts: 236
Likes: 169
From: Brooklyn
I have a stupid question - for getting new OEM gaskets and seals, where is the best place to get them from? Actual dealers? Indy places like JP ? Or is there an on line ordering site for HD stuff?
I will have a cam or 2 to do.
I will have a cam or 2 to do.
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HDF Community Team
Joined: Dec 2005
Posts: 5,421
Likes: 2,621
From: NC USA
A dealership is the only place you can get OEM. If you don't live close to a dealer, life is tough.
HD put an end to dealerships selling out of their assigned territory, including mail order.
HD put an end to dealerships selling out of their assigned territory, including mail order.
Cruiser
Joined: Aug 2020
Posts: 236
Likes: 169
From: Brooklyn
