oil pressure drop
Thread Starter
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6th Gear
Joined: Aug 2009
Posts: 10
Likes: 0
From: East Texas
oil pressure drop
I just got my ’48 chopper project up and running, but am having a couple of issues. I’m hoping someone here can help.
Oil pressure runs around 50lbs for about 2 minutes after starting, then drops to 10. One trip around the block and the pressure drops to 0.
1954 heads, tapped for external oiler
S&S oil pump
50wt oil
Carb from the AMF years (just using what I got)
Also, the front header pipe is discolored beyond blue, showing way hot after only 1.2 mile ride and maybe a total of 30 minutes idling, while the rear pipe still looks like new. I'm running 2 into 1 with a squish pipe, nothing yet past the wye pipe.
Can ya'll help me out here?
This is my first pan and my first chop. I’ve got a lot to learn about this old motor, and there’s nothing like learning from those who have gone there before…
Oil pressure runs around 50lbs for about 2 minutes after starting, then drops to 10. One trip around the block and the pressure drops to 0.
1954 heads, tapped for external oiler
S&S oil pump
50wt oil
Carb from the AMF years (just using what I got)
Also, the front header pipe is discolored beyond blue, showing way hot after only 1.2 mile ride and maybe a total of 30 minutes idling, while the rear pipe still looks like new. I'm running 2 into 1 with a squish pipe, nothing yet past the wye pipe.
Can ya'll help me out here?
This is my first pan and my first chop. I’ve got a lot to learn about this old motor, and there’s nothing like learning from those who have gone there before…
Road Warrior
Joined: Dec 2007
Posts: 1,854
Likes: 20
From: Eagle River WI
That oil pressure saga is normal Both my 46 and 52 start off like this and after say 10 miles at 60 degrees oil press on 0-30 pressure gauge reads 0 I do run clear return lines to the oil tank so I can watch the oil return one shot at a time When you said idle for 30 minutes you were kidding right?
Seasoned HDF Member
Joined: Oct 2005
Posts: 7,481
Likes: 3,677
From: Santa Klaus County, Cali
FWIW...
1. A pan at idle for 30 minutes is not a good idea
2. You do not need a gage on pan motors for oil. If you pull the cap and can see oil returning to the tank, you have oil pressure. At idle and especially on hot days oil pressure seems to be non-existent, but its there... never hurts to crack the throttle though.
3. Choice of oil seems to be pretty wide. I use only HD 60 wt because that is all I have ever run in my pans.
4. They used a couple of different carbs form the AMF years. If it is working fine, stick with it until you gain a bit more knowledge before you start tearing stuff off and add on anything else.
1. A pan at idle for 30 minutes is not a good idea
2. You do not need a gage on pan motors for oil. If you pull the cap and can see oil returning to the tank, you have oil pressure. At idle and especially on hot days oil pressure seems to be non-existent, but its there... never hurts to crack the throttle though.
3. Choice of oil seems to be pretty wide. I use only HD 60 wt because that is all I have ever run in my pans.
4. They used a couple of different carbs form the AMF years. If it is working fine, stick with it until you gain a bit more knowledge before you start tearing stuff off and add on anything else.
Thread Starter
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6th Gear
Joined: Aug 2009
Posts: 10
Likes: 0
From: East Texas
Thanks for all the responses.
That was 30 minutes total idle time! 10 minutes to warm up, then cool off to tighten the heads. did that again. I'm new to pans, not all scooters. Thanks for all the concern! Made me chuckle.
The oil flow is good thru the tank. great flow. So if that's the case I can do away with the gauge?
That was 30 minutes total idle time! 10 minutes to warm up, then cool off to tighten the heads. did that again. I'm new to pans, not all scooters. Thanks for all the concern! Made me chuckle.
The oil flow is good thru the tank. great flow. So if that's the case I can do away with the gauge?
Seasoned HDF Member
Joined: Oct 2005
Posts: 7,481
Likes: 3,677
From: Santa Klaus County, Cali
I say as long as ya got the idiot lights on the dash you are good to go. But that is just one opinion.
Follow break in procedure for the new motor.
You get the chance, everyone appreciates pan ****!
Follow break in procedure for the new motor.
You get the chance, everyone appreciates pan ****!
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Tourer
Joined: Feb 2009
Posts: 404
Likes: 0
From: L.A. (Lower Alabama)
You also mentioned blue front pipe. Jetting, obviously, is the same for both cylinders. So start with the rubber bands. How do the plugs look? Valvetrain sounds any different in the front? Stock ignition?
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Thread Starter
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6th Gear
Joined: Aug 2009
Posts: 10
Likes: 0
From: East Texas
[quote=panz4ever;7624166]I say as long as ya got the idiot lights on the dash you are good to go. But that is just one opinion.
What dash? LOL
I just cut the neck off today for a little more rake...bringing the front of the frame down to where it oughta be. A few days before I can crank her up again. It shouldn't be too cold to ride when I'm done. Lucky Texas me!!! Pics soon to follow.
Stick-o-scoped both cylinders. both sounded to be ok. Stock points.
What dash? LOL
I just cut the neck off today for a little more rake...bringing the front of the frame down to where it oughta be. A few days before I can crank her up again. It shouldn't be too cold to ride when I'm done. Lucky Texas me!!! Pics soon to follow.
Stick-o-scoped both cylinders. both sounded to be ok. Stock points.
Advanced
Joined: Feb 2009
Posts: 57
Likes: 18
From: Fresno. CA.
Low oil pressure & over lean front cylinder issues.........
Have you checked your oil pump brother ?
Make sure that the engine is cold & first, inspect the check valve spring tension & check ball, as a dirty seat can cause the oil to bleed past the check ***** & cause your oil pressure to drop once the bike is warmed up.
Get a good maglite or a pistol or rifle bore light (normally a bore light is for checking gun barrels, but they're excellent for working on bikes) & look down into the bore to make sure the you can see a shiny. smooth & unpitted seat (use a cue tip dipped in a little carburetor cleaner to wipe away any oil residue).
If the seats look like they might have a slight amount of pitting then what you do is to tack-weld a check ball onto a piece of arc welding rod, put a little fine valve lapping compound on the tool you'd just made & spin the tool back & forth until you see a nice shiny new seat for the check ball to sit in repeat the same procedure with the relief valve ( this is the valve that sticks out in a 90 degree angle from the right side of the oil pump itself.
Once again you need to check the spring tension, and the relief valve, looking for any pitting or foreign particles that might be preventing the ball & relief valve themselves from making flush contact with their respective seats. Look at the relief valve itself, does it show any pitting around it's exterior surface ? If it does then get a new one. For any flaws of the valve itelf will allow blow-by. You'll be surprised at the increase in your oli pressure even just at idle.
An old trick is to also stretch the springs just a bit to produce more force when they're compressed, or if you like you can also purchase stiffer springs for both the the check & relief valves, then you'll see a difference in your oil pressure as it will be stronger than it was before.
And last, but not least, pull the oil pump breather valve & screen to make sure that it's not clogged up or out of time, and trust me, if you're breaking in a fresh motor then you're going to find particles in that screen, so after putting about 200 miles on the bike, remove the oil pump breather & check it out.
Mind you, that taking out the oil pump breather valve & screen involves removing the timing cover, but if you want to have an engine with a long life span then all of this will be worth it in the long run
Remember to make sure that you put it back in with the timing marks just where they were or you'll throw off the timing of the breather gear itself & that will cause problems all it's own, so dab some bright color of paint on the oil breather valve screen gear & the pinion gear where they were meshed together (remembering not to rotate the engine while you have the breather gear out for inspection).
I know that this may sound like a lot of work but it really isn't, and isn't having a bike you can count on to make to make either a cross country ride, or just a pleasant local putt worth some time well spent in doing the maintenance ? People on their new computerized Harleys think that their bikes won't ever break down, but the damned things do, and the best revenge to all their crappy comments about our antiques just makes me all the more proud of my old 52 Pan. I've had my Pan since I was 15 (I'm 53 now) & I wouldn't trade it for 3 of those new garbage bikes that come from Milwaukee these days.
One last thing, and it's about the front cylinder runnig too lean, take off the air cleaner & look at where the stream from the accelerator pump is squirting. If it's squirting toward the rear cylinder then just drop the float bowl & take a small wrench that fits the jet & slowly turn it until the stream shoots directly down the center of the intake (the accelerator pump jet is a press fit, so there are no threads to mess up), this should ease the problem up a good deal & can stop any carburetor backfire that you may have been experiencing. Also check your timing, and possibly put a one grade colder plug in the front head.
E-mail me here with a personal message to let me know how everything is working, and if I can be of any further help then just let me know brother, as restoring older Harleys, Indians & British iron has been my job & my passion for over 38 years now.....
-Ron
Make sure that the engine is cold & first, inspect the check valve spring tension & check ball, as a dirty seat can cause the oil to bleed past the check ***** & cause your oil pressure to drop once the bike is warmed up.
Get a good maglite or a pistol or rifle bore light (normally a bore light is for checking gun barrels, but they're excellent for working on bikes) & look down into the bore to make sure the you can see a shiny. smooth & unpitted seat (use a cue tip dipped in a little carburetor cleaner to wipe away any oil residue).
If the seats look like they might have a slight amount of pitting then what you do is to tack-weld a check ball onto a piece of arc welding rod, put a little fine valve lapping compound on the tool you'd just made & spin the tool back & forth until you see a nice shiny new seat for the check ball to sit in repeat the same procedure with the relief valve ( this is the valve that sticks out in a 90 degree angle from the right side of the oil pump itself.
Once again you need to check the spring tension, and the relief valve, looking for any pitting or foreign particles that might be preventing the ball & relief valve themselves from making flush contact with their respective seats. Look at the relief valve itself, does it show any pitting around it's exterior surface ? If it does then get a new one. For any flaws of the valve itelf will allow blow-by. You'll be surprised at the increase in your oli pressure even just at idle.
An old trick is to also stretch the springs just a bit to produce more force when they're compressed, or if you like you can also purchase stiffer springs for both the the check & relief valves, then you'll see a difference in your oil pressure as it will be stronger than it was before.
And last, but not least, pull the oil pump breather valve & screen to make sure that it's not clogged up or out of time, and trust me, if you're breaking in a fresh motor then you're going to find particles in that screen, so after putting about 200 miles on the bike, remove the oil pump breather & check it out.
Mind you, that taking out the oil pump breather valve & screen involves removing the timing cover, but if you want to have an engine with a long life span then all of this will be worth it in the long run
Remember to make sure that you put it back in with the timing marks just where they were or you'll throw off the timing of the breather gear itself & that will cause problems all it's own, so dab some bright color of paint on the oil breather valve screen gear & the pinion gear where they were meshed together (remembering not to rotate the engine while you have the breather gear out for inspection).
I know that this may sound like a lot of work but it really isn't, and isn't having a bike you can count on to make to make either a cross country ride, or just a pleasant local putt worth some time well spent in doing the maintenance ? People on their new computerized Harleys think that their bikes won't ever break down, but the damned things do, and the best revenge to all their crappy comments about our antiques just makes me all the more proud of my old 52 Pan. I've had my Pan since I was 15 (I'm 53 now) & I wouldn't trade it for 3 of those new garbage bikes that come from Milwaukee these days.
One last thing, and it's about the front cylinder runnig too lean, take off the air cleaner & look at where the stream from the accelerator pump is squirting. If it's squirting toward the rear cylinder then just drop the float bowl & take a small wrench that fits the jet & slowly turn it until the stream shoots directly down the center of the intake (the accelerator pump jet is a press fit, so there are no threads to mess up), this should ease the problem up a good deal & can stop any carburetor backfire that you may have been experiencing. Also check your timing, and possibly put a one grade colder plug in the front head.
E-mail me here with a personal message to let me know how everything is working, and if I can be of any further help then just let me know brother, as restoring older Harleys, Indians & British iron has been my job & my passion for over 38 years now.....
-Ron