Need help with a dead Road King - carb'd

[Ohio HD]

pull the oil pump

The keys in the oil pump "should" shear before an object jamming the oil pump could cause the oil pump worm gear on the crankshaft to break. I say "should", but anything is possible. The oil pump drive shaft and the worm gear at the end of the shaft that the crank turns, it may have come lose due to a snap ring failure, allowing that gear to float in and out causing the worm gear on the crank to jam and split.

I'd carefully remove the debris and see what you can find as some evidence of the cause. Hopefully the pinion shaft is ok, with no more than some scuffing that you might be able to sand down with fine emery cloth.

You also need to check for bent valves. Not trying to make you feel bad, just that there could be more damage. Also the shrapnel could be in the crankcase as well. Depends on how long there may have been some chips or fine metal floating around before the motor quit. I'd drain the oil filter into a small pan, and then once it's pretty dry, cut it open with tin snips so not to make fine metal dust with a saw. See what's in there. Also try to drain the oil tank through some old white t-shirt or thin white towel into a clean pan.
 

[SixShooter14]

pull the oil pump

The keys in the oil pump "should" shear before an object jamming the oil pump could cause the oil pump worm gear on the crankshaft to break. I say "should", but anything is possible. The oil pump drive shaft and the worm gear at the end of the shaft that the crank turns, it may have come lose due to a snap ring failure, allowing that gear to float in and out causing the worm gear on the crank to jam and split.

I'd carefully remove the debris and see what you can find as some evidence of the cause. Hopefully the pinion shaft is ok, with no more than some scuffing that you might be able to sand down with fine emery cloth.

You also need to check for bent valves. Not trying to make you feel bad, just that there could be more damage. Also the shrapnel could be in the crankcase as well. Depends on how long there may have been some chips or fine metal floating around before the motor quit. I'd drain the oil filter into a small pan, and then once it's pretty dry, cut it open with tin snips so not to make fine metal dust with a saw. See what's in there. Also try to drain the oil tank through some old white t-shirt or thin white towel into a clean pan.
 

Thanks I had intended on checking the oil for metal. Is there a way to check for bent valves without pulling the heads? I do have a borescope, would contact be obvious enough on the piston to see?

 

[kd]

pull the oil pump

The keys in the oil pump "should" shear before an object jamming the oil pump could cause the oil pump worm gear on the crankshaft to break. I say "should", but anything is possible. The oil pump drive shaft and the worm gear at the end of the shaft that the crank turns, it may have come lose due to a snap ring failure, allowing that gear to float in and out causing the worm gear on the crank to jam and split.

I'd carefully remove the debris and see what you can find as some evidence of the cause. Hopefully the pinion shaft is ok, with no more than some scuffing that you might be able to sand down with fine emery cloth.

You also need to check for bent valves. Not trying to make you feel bad, just that there could be more damage. Also the shrapnel could be in the crankcase as well. Depends on how long there may have been some chips or fine metal floating around before the motor quit. I'd drain the oil filter into a small pan, and then once it's pretty dry, cut it open with tin snips so not to make fine metal dust with a saw. See what's in there. Also try to drain the oil tank through some old white t-shirt or thin white towel into a clean pan.
 

Thanks I had intended on checking the oil for metal. Is there a way to check for bent valves without pulling the heads? I do have a borescope, would contact be obvious enough on the piston to see?

 
Thanks I had intended on checking the oil for metal. Is there a way to check for bent valves without pulling the heads? I do have a borescope, would contact be obvious enough on the piston to see?

 


It should be obvious in the carbon as a shiny spot along the arc of the valve pocket eyebrow.  If you slip the rocker cover pans off and with the pushrods out all 4 valves should be at full extension (up).  The exhaust should be the same height as each other and the intakes likewise.   If you can pry down on the valve stems they should feel free when starting to move and return fully when released slowly.

If you have an angle mirror tip with your endoscope you can attach to the lens (mine came with one) you can look up at the valves when the scope is inserted through the spark plug hole.  When you have the pushrods out the valves should appear to be seated.


 

[Ohio HD]

Thanks I had intended on checking the oil for metal. Is there a way to check for bent valves without pulling the heads? I do have a borescope, would contact be obvious enough on the piston to see?

A leak down test will tell you if there are any issues with holding compression. Also the bore scope is helpful to see what's what in there also.

[Ohio HD]

Also, I'm sure you will, but just to be sure, look in the breather valve for metal, as well check the breather valve bore for damage. Again, not likely, but takes only a few minutes to check it out.

[kd]

Also, I'm sure you will, but just to be sure, look in the breather valve for metal, as well check the breather valve bore for damage. Again, not likely, but takes only a few minutes to check it out.

  The breather valve will give a good indication of debris migration.  I don't remember if the 95 was a plastic unit but the 98 was.  Any (or some of) the sharp pieces of the shrapnel that entered it will be imbedded in the outer surface between the breather and the breather bore.  Minor scoring shouldn't be a problem and you'll have the opportunity to decide on replacing it with another OEM plastic unit or go with an aftermarket metal one.

[SixShooter14]

Also, I'm sure you will, but just to be sure, look in the breather valve for metal, as well check the breather valve bore for damage. Again, not likely, but takes only a few minutes to check it out.

  The breather valve will give a good indication of debris migration.  I don't remember if the 95 was a plastic unit but the 98 was.  Any (or some of) the sharp pieces of the shrapnel that entered it will be imbedded in the outer surface between the breather and the breather bore.  Minor scoring shouldn't be a problem and you'll have the opportunity to decide on replacing it with another OEM plastic unit or go with an aftermarket metal one.

Thanks, it's a '97 and OEM was plastic but I installed a metal breather gear back in 2020 when I had it apart. I'll definitely give it a look.

[Ohio HD]

Oh and another thing....       ridgedthumper already said to check out the lifter rollers. But like he once told me, and I believe it, the lifter is the best oil filter in the motor. I'd also pull them apart and wash them out if you plan to reuse them.

It's a lot to go over. But no point in cutting any corners on inspection at this point.

Also, a quick leak down for the sake of finding a leak in the upper end is just put air pressure straight into the spark plug hole. You don't need a leak down tester just to see if there is actual damage causing a leak. It should be pretty evident.

[SixShooter14]

Monday night updates.

Breather Gear:
Found 1 little chunk INSIDE the breather gear, it was small enough to fit through the breather screen but larger than a splinter. No scratches or gouges on the steel gear or Al housing. The very back of the housing is a little rough but it looks more like casting/wear than from damage.

Pushrods/Lifters:
All rods were still locked down. 3 rods could be wiggled by finger, the front exhaust was pretty tight but loosened as soon as I started shortening (as expected) Rods look fine.
Lifters all look fine as well, no scratches or metal debris on them anywhere. The intake rollers show very light witness marks around them. All roll good and smooth with no side to side rocking at all.

Cam:
Gear looks fine. Lobes all look fine, showing very light witness marks matching with the rollers. Cam thrust washer look fine no major scratches, bearing didn't show any debris looking from the outside with a flashlight.

Pinion gear:
Key was still in the pinion gear and was curled up out of the keyway. Keyway shows some light scuffing on the front of the outboard end. The end of the keyway that would be under the pinion gear.


I didn't borescope the cylinders yet. I think I'll just pull the rocker boxes off for peace of mind and then decide on heads.


I have pictures of the gears, key/keyway, and breather gear/bore. If anyone thinks it would be helpful, I can post them.

Should the oil pump gear spin by hand? I tried turning it with my fingers but it didn't budge? 

[SixShooter14]

ALSO...

I want to thank all of y'all for helping out with questions, answers, ideas, and opinions. It is MUCH appreciated 

[rigidthumper]

The return side of the oil pump is that cavity directly underneath the pinion gear- some of those chunks had to get in the return gears, keeping it from freely rotating.

[SixShooter14]

The return side of the oil pump is that cavity directly underneath the pinion gear- some of those chunks had to get in the return gears, keeping it from freely rotating.

yep, I see what you're saying in the SM picture. Goes out the bottom, through the return gears and to the filter?

[rigidthumper]

Yep- and the first chunk to hit would have stopped the return side, possible both sides. Just have to complete the tear down to see how the keys in the pump fared.

[SixShooter14]

Yep- and the first chunk to hit would have stopped the return side, possible both sides. Just have to complete the tear down to see how the keys in the pump fared.

welp, keys in the pump fared just fine.... The key on the drive gear in the cam chest was sheared off as well as a few gear teeth.

So, I now have the pump off. The motor side gears had a few chunks bound up in the gears but the keys and gears on that side are ok... But there's is a couple gouges in the gear area and a ring cut around the idler gear. Picture below.
You cannot see attachments on this board.


I also drained the oil (did NOT pull the oil pan) no chunks there and just real fine particles on the drain plug like you would typically see. I haven't pulled the filter off yet either but that'll be next.

[Ohio HD]

Unfortunately you can't get the oil pump body from HD any longer. Their part number was (is) 26226-92. Someone may have a near new condition used pump more likely than just the pump body in good condition. The body is generally what suffers as you can see.

FYI: HD doesn't sell the pump assembly any longer either. 

[SixShooter14]

Unfortunately you can't get the oil pump body from HD any longer. Their part number was (is) 26226-92. Someone may have a near new condition used pump more likely than just the pump body in good condition. The body is generally what suffers as you can see.

FYI: HD doesn't sell the pump assembly any longer either. 

I'm just going to order a new pump assembly gears and all.


So, I also ran the borescope down the spark plug holes. How obvious would piston - valve contact be? Would there be noticeable gouges/contact marks?

[Ohio HD]

So, I also ran the borescope down the spark plug holes. How obvious would piston - valve contact be? Would there be noticeable gouges/contact marks?

In most cases yes, you would see a clean spot if a valve hit hard. It's also possible that a light hit could bend a valve, one of those hit it just right situations. I'd hold any concerns until you pipe some air into the cylinders to see about leaks, it should be heard easily with 45 or 50 PSI.

Are you going to get an S&S pump? Just curious.   

[SixShooter14]

So, I also ran the borescope down the spark plug holes. How obvious would piston - valve contact be? Would there be noticeable gouges/contact marks?

In most cases yes, you would see a clean spot if a valve hit hard. It's also possible that a light hit could bend a valve, one of those hit it just right situations. I'd hold any concerns until you pipe some air into the cylinders to see about leaks, it should be heard easily with 45 or 50 PSI.

Are you going to get an S&S pump? Just curious.   

oh year, I completely forgot about shooting some air in the cyl.


no on S&S, I considered but went with a V-twin/Sifton replacement.

[kd]

Six, remember the leak down test will have to be done at a point that you can still hold the engine from rolling over when you put the air to it.  If you disassemble it too far to clean the debris you may lose the opportunity.

To answer your scope question,  you should be able to see contact in the carbon or the piston with a good camera.  I know my cheaper erosion certainly will.  I have no carbon buildup and can read the part numbers and the eyebrow area is clear.

[SixShooter14]

mmk...I haven't built a spark plug hole/gauge adapter, but I used the air spray gun with the rubber tip and applied 50 psi of air to the spark plug holes (1 at a time) and both made noise like you get when plugging an air hose into a tank. A echoie noise of air movement, I didn't sit for too long aired up but it did spew when I removed the air nozzle. I couldn't feel any air coming from the pushrod holes.

I have one of those 90 degree mirrors for my borescope...somewhere.

[kd]

mmk...I haven't built a spark plug hole/gauge adapter, but I used the air spray gun with the rubber tip and applied 50 psi of air to the spark plug holes (1 at a time) and both made noise like you get when plugging an air hose into a tank. A echoie noise of air movement, I didn't sit for too long aired up but it did spew when I removed the air nozzle. I couldn't feel any air coming from the pushrod holes.

I have one of those 90 degree mirrors for my borescope...somewhere.

Are your pushrods removed?

[SixShooter14]

mmk...I haven't built a spark plug hole/gauge adapter, but I used the air spray gun with the rubber tip and applied 50 psi of air to the spark plug holes (1 at a time) and both made noise like you get when plugging an air hose into a tank. A echoie noise of air movement, I didn't sit for too long aired up but it did spew when I removed the air nozzle. I couldn't feel any air coming from the pushrod holes.

I have one of those 90 degree mirrors for my borescope...somewhere.

Are your pushrods removed?

yes, rods, lifters, and tappet blocks are removed

[SixShooter14]

Carb and air filter are still on. But with the cam removed... I doubt air from the bottom end would vet out the top ('97 is a top breather)

[Ohio HD]

The rings will seal where ever they are in the bore. If you have a bent valve you should hear air coming out the carburetor, or the exhaust. Unless it happened to be a minute leak.

An easy air fitting if you have a welder is weld a quick disconnect air fitting to a 14mm spark plug body that has the ceramic removed. Slap an o-ring in place of the spark plug gasket. I made one 30+ years ago one evening I needed one. Still have it. 

[kd]

mmk...I haven't built a spark plug hole/gauge adapter, but I used the air spray gun with the rubber tip and applied 50 psi of air to the spark plug holes (1 at a time) and both made noise like you get when plugging an air hose into a tank. A echoie noise of air movement, I didn't sit for too long aired up but it did spew when I removed the air nozzle. I couldn't feel any air coming from the pushrod holes.

I have one of those 90 degree mirrors for my borescope...somewhere.

Are your pushrods removed?

yes, rods, lifters, and tappet blocks are removed

   What Ohio said while I was typing.

Then the valves should be fully on their seats and sealing. If the air up sound stops when it gets up to your pressure setting and it holds air (spews it out when you remove it), that's a good sign.  It's much better if you can valve it off and listen undistracted for seeping under the pressure you have added.  You can listen at the exhaust and intake.  As you know, if it looses air into the crankcase it's rings and not head / valve damage.