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1978 T140E EX
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Discussion Starter · #1 ·
Replacing the original OPRV, oil seals and pump since I had low pressure at idle and seemed slow to build pressure. Last week I pulled the PRV to clean and noted the piston was stuck towards the screen. Freed it up cleaned it and reinstalled. The oil pressure seemed a little better on the test gauge at idle and still slow to build pressure testing oil pressure).
I went ahead and ordered PRV (screen was shot), oil pump and seals. Yesterday pulled the points plate, advance unit and timing cover. I haven't removed the crank seal from the cover yet but looking at it I see there are bits missing. Ive read about inverted seals but this seal seems to be failing due to age/degradation. I took the old pump apart and the pistons/bores are smooth and slide nice with no slop, spring ball look fine the only out of norm appears to be drive block has some wear area.
I'm hoping the seal is the cause for the pressure issues otherwise it will be on to worser case scenarios.
In hindsight I should have just taking it a part first and gotten by with just replacing the bad seal...oh well. Since I have the new parts Im going to go ahead and install all of them. I'll post an "after" pressure test once I get it back together.
Is there anything I need to do to "prime" the pump? Any comments or advice is welcome.
LM Ricky
 

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Looks like that crank seal's useful life is well behind it! Hopefully that's all it is,
When I bought the two seals for the crank and points, I put the same higher quality seals in both
One supplier website said this one you need to use on your crank but this one's okay for points because there's no pressure.
 

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Hi,
its nice when you find a fault related to your symptoms, that will definitely give you low oil pressure.

If it is the original seal it will be 44 years old, it is remarkable that it lasted that long in hot oil.

have you found the missing piece, I would worry that it might block the oilways if it has gone inwards (towards crankshaft) instead of outwards (towards timing case).

make sure your new gasket lines up without blocking any oil holes, some replacement gaskets are really badly cut.

regards
Peg
 

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Hi LM,
It looks like the oil pump is going to be a timely replacement also, the drive face of the return plunger looks worn and the pressure/feed plunger has some nasty scores in the working area.

Microphone Font Audio equipment Gas Wire



The plunger oil pump is very good at self priming, I have not heard of one that failed to self prime. I would however squirt engine oil inside the pump and on the slider before fitting, to help protect the surfaces on the first couple of strokes.
More importantly, I would raise the pistons to near TDC (hopefully they are at 38 degs btdc already ready for the refit of the ignition) then just before the timing cover goes on pump oil into the end of the crankshaft until you feel the resistance of the big end shell gap. If you can get the cover on quickly before too much oil flows back, then you will have a reserve of oil already in the crankshaft for that fist start up. If you turn the crank to set the timing make sure the pistons are returned to tdc, the oil you pumped in will then not drain oit of the big ends. On startup centrifugal forces will force the oil reservoir into the big ends protecting them until the oil pump refills the crankshaft.

regards
Peg.
PS
In the photo of your timing cover it looks like there is a hole in the oil gallery where a casting vent was removed, I presume this is a trick of the light in the photo, as a hole here would result in zero oil pressure.
 
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1978 T140E EX
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Discussion Starter · #7 ·
More importantly, I would raise the pistons to near TDC (hopefully they are at 38 degs btdc already ready for the refit of the ignition)
😳 Uh-oh.... I didnt position the pistons at all. I just scribed two lines, one on the breaker plate and the other on the the boss of the cover. I thought that would get me close and i could check dwell and timing with 50 year old Dixco tune up kit my father had that I haven't used in 45 years. (I vaguely remember using it to set my dwell and timing but....maybe that was on the '66 Alpine). Sounds like another rookie mistake and another forum post in my future.
 

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Hi Ricky, Scribing points cavity & points plate works good. Just spread points with thumb nails & slide plate over AAU, check point gap, strobe time.

When putting AAU back in really make sure it’s centered on peg in cam. Then hold it inwards with one hand to make sure it’s not cocked on taper. (Of course you’ve already cleaned tapers).
Then install bolt & tighten it with other hand. This goes a long ways to prevent AAU wobble.
Don
 

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😳 Uh-oh.... I didnt position the pistons at all. I just scribed two lines, one on the breaker plate and the other on the the boss of the cover. I thought that would get me close and i could check dwell and timing with 50 year old Dixco tune up kit my father had that I haven't used in 45 years. (I vaguely remember using it to set my dwell and timing but....maybe that was on the '66 Alpine). Sounds like another rookie mistake and another forum post in my future.
Hi LM,
Not necessarily a problem, as long as you have the original Lucas Points advance unit with the locating tang (or Lucas Rita Electronic ignition that also has it) then all will be fine, I have been mucking about for so long with aftermarket ignition systems that don’t have this simple but brilliant feature that I forget how easy it is to fit the original Lucas setups.
 
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Discussion Starter · #10 ·
make sure it’s centered on peg in cam.
as long as you have the original Lucas Points advance unit with the locating tang
Thanks Don - Thanks Peg
AAU is original and seems to actuate fine and springs back well.
I see the "key slot" on the AAU tapered end but there is no key or peg you mention in cam bore.
The AAU taper slides into the tapered bore and seats but it can rotate 360deg. I done feel anything in the bore that would indicate where a key would have been (if it broke off).
Now Im really stumped.
EDIT to add photos
 

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Rick, Back to the pump, did you bench test it before taking it apart? Just curious if it was leaking too.

It is imperative you flush new pump with motor oil. One side at a time. Pull piston out. Put finger over top port. Fill bore with oil, then put in piston & push down. Oil will leak by finger. That’s ok. The push piston in all the way forcing oil out lower bore. Do this about 4 times.
Then leak test new pump. I think I sent you videos on how to test.
Even a Morgo pump needs flushing & testing. Anything could happen, so we never take a chance.

Without testing, including drive block clearance, you have no idea how oil pump really is. Since your videos show pressure rising dramatically just off idle, I’d expect it was still pumping well.

My seal had been in motor since ‘74. About 3k miles. I resealed leak at timing cover. Was in storage 34 years starting in ‘79. 9500 miles. Out of storage I covered 27k miles on that old seal. Torn down motor last sping due to failed timing side metric main bearing.
I was most curious as to condition of crank seal. Shockingly still supple & very little lip wear. Oil pressure at hot idle was excellent. About 30# @ 1000.
To make oil light wink you had to clutch motor down to barely running. Ka chunk, ka chunk idle.
No way can Morgo pump match the original oval port. Visually even the return stream is less now.
Original pump the return check ball seat got chewed up from metal chips from bearing failure. Supply side of pump perfect. Visual marks on pistons are common. If after light polish pistons are not loose in bores they can be reused.
The cross heads in pistons can/will wear. When measuring clearance of drive block it must be positioned at the “working area” where wear is. You push block to back, feeler gauge to back it’ll measure ok, because this part doesn’t wear. I generally renew drive block at 50% if wear limit. A worn block can give a lot of lost motion, which reduces oil volume pretty quickly as effective stroke is so short. If cross head clearance is loose with new block, pump must be replaced.

Often scores on pistons is from particulates in the oil. Dirty oil! In frame filter goes a long ways in stopping particles from getting into pump & motor. Being surgically clean during filter changes & feed hose changes matters.

None of the above is hard. You just have to do it. It insures long term success.
Don
 

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Discussion Starter · #12 · (Edited)
Back to the pump, did you bench test it before taking it apart?
Hey Don - No I didn't test the old pump or the new one yet but I will.
Im in a holding pattern and perplexed since there is no alignment pin in the cam bore for the AAU.
I've just searched the forum and saw a few folks had the same issue but it was sheared and they were able to see in the bore and use the witness mark as a close line up reference *See below. Unfortunately I don't see any witness mark as to where the pin would have been.
I don't ever remember removing the points plate or advance timing unit back in 1980. When I removed the AAU yesterday I removed the bolt, screwed in a longer 5/16-24 bolt to slide hammer it off.

Maybe this is a good time/reason to install electronic ignition. (I saw a few other posts where they were having to remove the pin in order to install their EI.)

EDIT* Add photo of "witness" mark of where I can now see where the AAU alignment pin was in the bore It is clearly round from different angles with magnifying glass. Oddly there is a straight "line" running down the bore and across the pin location. Almost appears to be a stress crack but it doesn't protrude to the O.D..
 

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Hi Ricky, Not a problem. Make your best guess. Then just barely snug the bolt. You may need to slip it later. Actually some of the later bikes didn't have the round peg.

Set motor to 38b mark. Lock AAU to full advance. Again don't final tighten AAU just yet. Now you should center points sub plate with the screw. Remember is the sub plate for points. Both plates. One or the other points will be just ready to open. Doesn't matter front or rear. With timing mark on 38 as I said, rotate the points backing plate in slots until points just begin to open. Use your ohm meter. When they just begin to open. Lock pillar bolts. Now go to rear wheel & move the motor again (plugs out) backwards, when come forwards until points open. Verify you are very close to timing mark 38 on rotor.

If you run out of slot you need to slip AAU in cam a bit. So you can get slot close to center. Will probably take a few attempts. You'll soon get the hang of it. Rather like initial set up of points after motor assembly with the twist of you need to slip AAU in camshaft taper. Tiger Cubs, BSA & various other bikes don't have the peg. So no big deal. Just a few hours of practice. 20 minutes if you're lucky. I'm never lucky!

Put in EI anytime you want. That's another subject. Don't let the broken peg decided that.
Don
 

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Discussion Starter · #14 ·
Thanks Don - I'll go over this and do some "research" before I attempt. Ive found some of your older posts with the washer to hold open the advance. I'll also check into using meter set to ohm's and guessing that is similar to using a dwell meter like in this old Dixco tune up kit. (I havent checked timing or points on anything in 45 years!)
Ive got the cover cleaned and new seals in but still need to clean case gasket face and check the pump then bolt it up before I line up the AAU etc.
Pump gasket lines up really well.
thanks for the help, ricky
 

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of cause...you don't really need to prime anything if you just leave it for a few days and let wet sumping take its own course🤣🤣🤣
Its a joke, but a sort of true one fortunately/unfortunately!
 

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Hi Ricky, Just removing pistons & squirting oil in bores of pump will be enough to allow it to pump right away.

Back to setting the AAU…
You center both sub plates. Your point gap will still be close enough for now from your last adjustment.

Remember last time on initial set up, you put motor to 38b, then rotated the big round plate untill points just opened. Then locked pillar bolts.

This time we’re going to lock pillar bolts with the slot centered. Motor at 38b.

Now… instead of rotating points plate, you’ll rotate AAU counter clockwise until points just open.

Old dwell meter is different than ohm meter.
We’ll use the ohm meter. With points closed ohm meter will read about .2-.3 ohms. That doesn’t matter. What matters is watching the meter change. If points wires are plugged in under tank meter will read about 70 ish ohms as you’ll be measuring coil circuit at same time. Again what we’re looking for is meter change. What will be hard is you cannot lock AAU & turn AAU in cam at same time. So you’ll need to use trial & error.

Again if you can see where peg in cam was it will really help to get close.
Don
 

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not having that little peg always makes me curse BSAs
 
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Hi speedrattle, Oh yes... Thing is with my Cub you set piston to the measurement with the "dip stick" tool. Then you don't lock AAU. It's set at the retarded position. Much simpler. No strobe timing, just static. I could put degree wheel on in place of AAU bolt, but it seems to work fine just static timed. It's a '64. They didn't strobe time the old bikes.
Don
 

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Discussion Starter · #20 ·
Remember last time on initial set up, you put motor to 38b,
Hmmm.... In my current state of inexperience and poor memory...If I ever did this at all it was in a very hazy 1980!
I found this recent post by Peg in @clamclam thread called "dry spark plugs t140v".
.....If you accidentally use the 38 deg BBDC line, your ignition timing will be 90 degrees wrong.
One of the easiest ways to check that you are are using the BTDC line is remove one spark plug, align the timing marks, then with a thin screwdriver see if you can feel if the piston is near the top of the barrel. IF you can feel the piston then you are at 38 degrees bTdc👍😁, if you cannot feel the piston then you are incorrectly set up at 38 degrees bBdc😫👎.
Regards
Peg
Link to full post #21
So I pulled my left plug, rotated rear tire in 5th gear until piston was up then aligned the pointer to the alternator mark that was currently in the window so I should be at 38BTDC🤞

Once I clean the case surface and install the pump I'll line up the AAU best effort to the witness mark of where the broken alignment pin was then.... re-read....
Back to setting the AAU…
At that point I will be asking some more questions!
Thanks to all for the replies!
 

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