Oil Dipstick Blowing Out
HDF Community Team
Joined: Jun 2006
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From: san antonio
The OP has not confirmed that the issue started after the big bore modification. But it the issue started after the big bore modification; I would still be looking at the crankcase breather system.
Last edited by djl; Aug 21, 2025 at 12:39 PM.
Seasoned HDF Member
Joined: Mar 2010
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From: Honah Lee
My 2002 FLHT does have a hose from the crank case to the filler neck which me thinks would be the same for the 2001 touring models. Built all bore 107" carbed motor, 124TQ/110HP, later stamped head breathers vented to the atmosphere, run hard hitting the rev limiter 5800 rpms with regularity and never blew out the dipstick. The OP very likely has an issue with the head breather system in spite of S&S that blowing out a dipstick is "OK normally", not buying it.
I had searched and seen one like yours. Got me.
The oil tank on my softail has a line off the oil bag going to the case.
Depending on year, also some where the Roadking went totally internal vent I think because finding one with a hose is a lot of searching.
Last edited by Jackie Paper; Aug 21, 2025 at 12:46 PM.
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Joined: Dec 2005
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From: poway
Not sure this is the issue or not but I was at a friends shop the other day with a bike in there that had very similar problems, but he was also burning oil. He tore it down and found that the S&S heads had an additional oil passage in them that the Harley lower rocker gasket covered up. Someone had done some rocker box maintenance or whatever and either didn't have a replacement S&S rocker gasket or thought the Harley was the same not realizing it covered a port in the heads and it created problems.
I believe that the patent has expired tho.
Last edited by Max Headflow; Aug 21, 2025 at 01:02 PM.
Seasoned HDF Member
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From: backwoods
Harley made a retro kit to vent to oil spout to engine. It changed around 2002 or 2003, your oil spout has no vent. They probably don't sell the kits anymore. Though could you just buy new oil spout and and fittings and hose? Gets rid of your venting hose.
Plug old hole. Not saying this will cure problem or what your problem is.
This was a problem on some 88s. When they went to 96" I think that was when they went to screw in caps. Gave up on reducing pressure.
Plug old hole. Not saying this will cure problem or what your problem is.
This was a problem on some 88s. When they went to 96" I think that was when they went to screw in caps. Gave up on reducing pressure.
Tourer
Joined: Aug 2022
Posts: 282
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From: Palm City, FL
If the dipstick is over 5 years or so old, replace it. I've found that the rubber seal gets hard and doesn't want to stay in very well. I also make sure to wipe the dipstick rubber clean, and inside the neck of the oil tank when checking it. I also run mine 1/2 way down the dipstick level (about 1/2 quart) below full.
Seasoned HDF Member
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From: backwoods
As for cleaning the dipstick rubber, it may make it tigher, but I would think harder going in dry,
Last edited by Rounders; Aug 21, 2025 at 07:06 PM.
Tourer
Joined: Aug 2022
Posts: 282
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From: Palm City, FL
It's still not difficult. Too easy still IMO, but haven't had the cleaned off fresh one blow out.
Road Master
Joined: Jun 2014
Posts: 965
Likes: 587
From: Arizona
This. Mine (2003 Twinkie) was doing this and dripping mad oil out the vent tube. Went halfway on the stick and it stopped.
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Seasoned HDF Member
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From: backwoods
I never said difficult, Just hard on the rubber stick in dry. If you replace yours every 5 years I guess it doesn't matter. I am not sure other people do. Not saying you not should replace.
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From: Honah Lee
If the dipstick is over 5 years or so old, replace it. I've found that the rubber seal gets hard and doesn't want to stay in very well. I also make sure to wipe the dipstick rubber clean, and inside the neck of the oil tank when checking it. I also run mine 1/2 way down the dipstick level (about 1/2 quart) below full.
Mine got loose on my Softail. With an o-ring added to a groove in it, it's tight.
Last edited by Jackie Paper; Aug 22, 2025 at 08:40 AM.