Oil Pressure
Thread Starter
|
Cruiser
Joined: Feb 2025
Posts: 123
Likes: 114
From: Beaverton, MI
Oil Pressure
would replacing the stock breather with the s&s reed breather valve cause oil pressure to drop? dash light starts to flicker on/off when the bike warms up, applying throttle shuts the light off, but as bike gets hotter light then stays on.
1993 FLTCU 80 in with ev13 cam, s&s reed breather, stock pipes with no name slip ons, pretty sure carb is stock but haven't torn into it yet to verify - everything else was stock on the bike when I got it though.
running fresh maxima 20-50 vtwin mineral oil
cleaned the oil screen at oil change a couple weeks ago - had the motor torn down and split apart for other issue. Less than 10 miles on the oil change. I will check the oil screen again tonight just to make sure the new cam/lifters are not self-destructing and clogging it with metal shavings.
Any other thoughts on cause or things to check? Should I rebuild the oil pump just because (looks like kit is under $20)? The bike showed 72k miles when I got it. I am pretty sure it was completely stock but no idea. Tore it down and pretty much went through everything but the oil pump, never removed that from the cases when I had it apart.
Also, I have no idea how the bike ran before. I got it running but never rode it before I tore it down and started fixing all the obvious issues with it, was still snow on the ground then.
1993 FLTCU 80 in with ev13 cam, s&s reed breather, stock pipes with no name slip ons, pretty sure carb is stock but haven't torn into it yet to verify - everything else was stock on the bike when I got it though.
running fresh maxima 20-50 vtwin mineral oil
cleaned the oil screen at oil change a couple weeks ago - had the motor torn down and split apart for other issue. Less than 10 miles on the oil change. I will check the oil screen again tonight just to make sure the new cam/lifters are not self-destructing and clogging it with metal shavings.
Any other thoughts on cause or things to check? Should I rebuild the oil pump just because (looks like kit is under $20)? The bike showed 72k miles when I got it. I am pretty sure it was completely stock but no idea. Tore it down and pretty much went through everything but the oil pump, never removed that from the cases when I had it apart.
Also, I have no idea how the bike ran before. I got it running but never rode it before I tore it down and started fixing all the obvious issues with it, was still snow on the ground then.
Last edited by mdkelley; Jun 24, 2025 at 10:26 AM.
HDF Community Team
Joined: Dec 2005
Posts: 5,376
Likes: 2,574
From: NC USA
No but the first chance you get to replace the reed with a normal gear, do so. Don't waste money on an aftermarket oil pump - stock is as good as it gets.
Number 1 cause of low oil pressure is worn tappet guides. Cheap lifters can add to that as well..
Number 1 cause of low oil pressure is worn tappet guides. Cheap lifters can add to that as well..
Thread Starter
|
Cruiser
Joined: Feb 2025
Posts: 123
Likes: 114
From: Beaverton, MI
I put in hylift johnson which seemed to be highly recommended here and on other forums so hopefully they aren't considered cheap lifters. Ones I took out were stockers in really good condition. Lifter bores and blocks felt good/tight but I didn't bore gauge them. The stock breather gear was in good shape too, I can put that back in whenever I open up the cam gear cover again... heard mixed feedback regarding the oem gear and the reed valve, probably should have just put stock one back in and saved $160 - some lessons I learn the hard way.
I didn't plan on spending $500 or so on an aftermarket pump, but probably won't hurt to rebuild the stocker and inspect the gears in it. The james gasket kit is pretty cheap, looks to have everything except a new spring.
I didn't plan on spending $500 or so on an aftermarket pump, but probably won't hurt to rebuild the stocker and inspect the gears in it. The james gasket kit is pretty cheap, looks to have everything except a new spring.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,326
Likes: 56,888
From: Michigan 15 Minutes East Of Hell
HDF Community Team
Joined: Dec 2005
Posts: 5,376
Likes: 2,574
From: NC USA
Oil pump kit is only gaskets and keys and shaft seal. Any "hylift johnson you bought in the past 4 years are counterfeit and very low quality. Johnson hasn't made Evo tappets in 5 or more years.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
Seasoned HDF Member
Joined: Jul 2014
Posts: 8,565
Likes: 3,318
From: Cental, MI
Check, then double check yer check ball...Just went thru that very thing..for some reason the check ball could hardly be coached off the seat..Quick check with a magnetic screwdriver..simple and Fast! Then..I had to hone the seat ...aggressively.. Dunno what Happened, but, assume some one decided to use a Hammer to "reseat" the ball..Bike had a bad Former Life!!!
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,830
Likes: 7,968
From: poway
Oil pump kit is only gaskets and keys and shaft seal. Any "hylift johnson you bought in the past 4 years are counterfeit and very low quality. Johnson hasn't made Evo tappets in 5 or more years.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
WFO Larry has them..
https://www.larrysmotorcyclemachine.com/lifters.html
Trending Topics
Thread Starter
|
Cruiser
Joined: Feb 2025
Posts: 123
Likes: 114
From: Beaverton, MI
Oil pump kit is only gaskets and keys and shaft seal. Any "hylift johnson you bought in the past 4 years are counterfeit and very low quality. Johnson hasn't made Evo tappets in 5 or more years.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
Again, nothing wrong with the stock oil pump. Replace the tappet guides and use only OE or S&S lifters and you oil pressure issues will disappear.
I thought I did my research and was getting quality parts for a reasonable price.
EDIT: disregard my rant above please -
https://www.facebook.com/permalink.php/?story_fbid=916399620486318&id=100063488652744
Last edited by mdkelley; Jun 24, 2025 at 06:22 PM.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
