HarleyTechTalk

well....news flash... I'm an idiot. 

Turns out I had the supply and return lines switched. So the pump was trying to suck from a new dry filter. I got the lines switched and re-primed the pump and voila, turning over with just the starter pegs out my pressure gauge... Sure enough, it was pumping the prime out and then running dry.

Now a new little issue, the pump return line that goes to the filter doesn't stick into the compression fitting far enough for the nut to tighten on it. Gonna get a little extension for that fitting and should have her back together tomorrow.

Well done Six
We all feel like idiots sometimes, but finding your mistakes and fixin' them, puts us way out in front of blokes who don't have a go at all.

the saga continues.

Bike starts and runs, idles good. Oil pressure stays well above the max of 30psi on my gauge.
BUT...the front cylinder is puffing out blueish smoke

Thinking a bad valve seal.

I didn't run it long enough to get really hot, just hot to the touch.
Back plug looks ok, but the front was black and just a bit wet.
Checked compression: 180 psi in both cyl. sorry, I don't have a leak-down tester.

Quote from: SixShooter14 on May 19, 2024, 04:59:46 PMthe front cylinder is puffing out blueish smoke

Thinking a bad valve seal.

Also could be excessive valve guide clearance or #2 ring upside down

Lately I have seen a lot of stock TC heads with one excessively bad valve guide when the rest show almost no wear. Don't know if it is something with the gasoline or the metallurgy of the guides.

Quote from: SP33DY on May 20, 2024, 08:29:32 AMAlso could be excessive valve guide clearance or #2 ring upside down

Lately I have seen a lot of stock TC heads with one excessively bad valve guide when the rest show almost no wear. Don't know if it is something with the gasoline or the metallurgy of the guides.

I put the pistons/rings in about 4 years ago and haven't had any issues since. I also replaced valve guides/seal then.

With the current work, I've not pulled the front head off, just the rear. (Which surprisingly is good) I'm thinking it's either a valve seal or maybe the new HVHP oil pump blew a head gasket. There's air puffing out both head breather holes, but no oil coming out anywhere.

It's only about an hour to pull the head. I can checkout the piston/cyl. then.

Quote from: SixShooter14 on May 20, 2024, 08:49:01 AM

Quote from: SP33DY on May 20, 2024, 08:29:32 AMAlso could be excessive valve guide clearance or #2 ring upside down

Lately I have seen a lot of stock TC heads with one excessively bad valve guide when the rest show almost no wear. Don't know if it is something with the gasoline or the metallurgy of the guides.

I put the pistons/rings in about 4 years ago and haven't had any issues since. I also replaced valve guides/seal then.

With the current work, I've not pulled the front head off, just the rear. (Which surprisingly is good) I'm thinking it's either a valve seal or maybe the new HVHP oil pump blew a head gasket. There's air puffing out both head breather holes, but no oil coming out anywhere.

It's only about an hour to pull the head. I can checkout the piston/cyl. then.

The likelihood of rings lining up is there but not great.  Same with a sudden valve seal issue with such a great amount of oil passing.  Those would be easy to diagnose with the disassembled components in hand. 

I would first consider the fact you have had the cam chest apart for the pump.  There is a better possibility that the cam timing is off and the blue smoke along with the black wet plug is cylinder was from fuel related to the cam timing.  When you start to break it down, pause at the cam plate and cams first. Your last time in there may have been a tooth out.

Change the plug and take it for a decent ride, see if it clears up.

Quote from: kd on May 20, 2024, 09:17:44 AM

Quote from: SixShooter14 on May 20, 2024, 08:49:01 AM

Quote from: SP33DY on May 20, 2024, 08:29:32 AMAlso could be excessive valve guide clearance or #2 ring upside down

Lately I have seen a lot of stock TC heads with one excessively bad valve guide when the rest show almost no wear. Don't know if it is something with the gasoline or the metallurgy of the guides.

I put the pistons/rings in about 4 years ago and haven't had any issues since. I also replaced valve guides/seal then.

With the current work, I've not pulled the front head off, just the rear. (Which surprisingly is good) I'm thinking it's either a valve seal or maybe the new HVHP oil pump blew a head gasket. There's air puffing out both head breather holes, but no oil coming out anywhere.

It's only about an hour to pull the head. I can checkout the piston/cyl. then.

The likelihood of rings lining up is there but not great.  Same with a sudden valve seal issue with such a great amount of oil passing.  Those would be easy to diagnose with the disassembled components in hand. 

I would first consider the fact you have had the cam chest apart for the pump.  There is a better possibility that the cam timing is off and the blue smoke along with the black wet plug is cylinder was from fuel related to the cam timing.  When you start to break it down, pause at the cam plate and cams first. Your last time in there may have been a tooth out.

  I'm 99% sure the gear timing was right... BUT it's definitely possible (I was pretty sure about the oil line routing too and we saw how that went ).

Quote from: Hossamania on May 20, 2024, 09:25:15 AMChange the plug and take it for a decent ride, see if it clears up.

that is awfully tempting. Definitely getting new plugs this week.

Breather timing would be more likely to cause oil issues than cam timing.

Six, I hadn't swallowed enough coffe yet when I responded.  I had twin cam brain. 

Quote from: kd on May 20, 2024, 01:20:32 PMSix, I hadn't swallowed enough coffe yet when I responded.  I had twin cam brain. 

haha...I knew what you meant.

As much as I hate to. I'll open the cam chest this evening and check all 3 gears are timed right.... Honestly, I'd almost rather pull the head off than open the cam chest

Quote from: SixShooter14 on May 20, 2024, 01:25:01 PM

Quote from: kd on May 20, 2024, 01:20:32 PMSix, I hadn't swallowed enough coffe yet when I responded.  I had twin cam brain. 

haha...I knew what you meant.

As much as I hate to. I'll open the cam chest this evening and check all 3 gears are timed right.... Honestly, I'd almost rather pull the head off than open the cam chest

. We'll you have to get the exhaust off anyway.   

Quote from: kd on May 20, 2024, 01:56:55 PM

Quote from: SixShooter14 on May 20, 2024, 01:25:01 PM

Quote from: kd on May 20, 2024, 01:20:32 PMSix, I hadn't swallowed enough coffe yet when I responded.  I had twin cam brain. 

haha...I knew what you meant.

As much as I hate to. I'll open the cam chest this evening and check all 3 gears are timed right.... Honestly, I'd almost rather pull the head off than open the cam chest

. We'll you have to get the exhaust off anyway.   

and the trans side cover and the torque arm... all of which I had off yesterday morning...  

Quote from: SixShooter14 on May 20, 2024, 01:59:45 PM

Quote from: kd on May 20, 2024, 01:56:55 PM

Quote from: SixShooter14 on May 20, 2024, 01:25:01 PM

Quote from: kd on May 20, 2024, 01:20:32 PMSix, I hadn't swallowed enough coffe yet when I responded.  I had twin cam brain. 

haha...I knew what you meant.

As much as I hate to. I'll open the cam chest this evening and check all 3 gears are timed right.... Honestly, I'd almost rather pull the head off than open the cam chest

. We'll you have to get the exhaust off anyway.   

and the trans side cover and the torque arm... all of which I had off yesterday morning...  

Getting good at it? 

Quote from: kd on May 20, 2024, 01:56:55 PM. We'll you have to get the exhaust off anyway.   

alright, exhaust is off... 2 things noticed thus far.
#1 The ignition timing was pretty far off. I must have missed my mark because it was off by probably 8-10 degrees of rotation when I re-static timed it. (CCW if it matters)...

#2 the exhaust valve has shiny oil on it and the inside of the exhaust port is coated with shiny oil on top and dry sooty oil on bottom.... (I'm guessing the oil is misted up from the exhaust gas and it sticks to the top of the port rather than the bottom?)


anyway.... next step? pull head or open cam chest? (or both?)

Quote from: SixShooter14 on May 20, 2024, 08:29:48 PM

Quote from: kd on May 20, 2024, 01:56:55 PM. We'll you have to get the exhaust off anyway.   

alright, exhaust is off... 2 things noticed thus far.
#1 The ignition timing was pretty far off. I must have missed my mark because it was off by probably 8-10 degrees of rotation when I re-static timed it. (CCW if it matters)...

#2 the exhaust valve has shiny oil on it and the inside of the exhaust port is coated with shiny oil on top and dry sooty oil on bottom.... (I'm guessing the oil is misted up from the exhaust gas and it sticks to the top of the port rather than the bottom?)


anyway.... next step? pull head or open cam chest? (or both?)

I would continue the cam chest component confirmation before moving on. Finding the timing error is good but not likely the cause of the wet oil.  Remember the plug was black for some time.

IMO if the intake valve is dry when you view it through the port after the intake manifold is removed and you find the exhaust wet it could indicate an exhaust valve seal is damaged. If the intake valve is wet too, the intake valve seal may be the one that is damaged.  If you didn't use viton seals it can be more common to damage them.  The viton seals will withstand more severe service conditions.  A few things could cause that including lack of lubrication that day that you put some miles on it trying to get the oil pressure up or just heat (even from the timing issue) allowing the seal hat to release from the top of the valve guide and start to float under the valve spring retainer.  Oil on the top only will be unburned vapor and the soot will of course be combusted oil. (the mass of the oil vapor will cause it to fling high as the exhaust valve is open on the exhaust stroke)

Hopefully the wet unburned oil isn't from cylinder damage occurring during the aforementioned lack of oil flow period. Slight amounts of oil slinging off the flywheels into the cylinders is part of the big picture keeping the pistons, rings and barrels lubed. The rear cylinder gets the first portion and if there is none left the scraper between the rear and front cylinder will reduce the chance of any getting into the front barrel.  That can cause piston, ring or cylinder damage.  Now that you have oil flow the oil may be introduced through a bad ring / piston seal.

For the above reasons (if it were me) I would stay on track and go one step at a time.  If you just tear it down it'll be hard to inspect everything with any real certainty of finding the demon that has appeared.  I am confident you will find the issue if you use good order in your approach.  Either way I expect you will find some mechanical fault other than the ignition timing.

     

Quote from: kd on May 20, 2024, 09:22:49 PMFor the above reasons (if it were me) I would stay on track and go one step at a time.  If you just tear it down it'll be hard to inspect everything with any real certainty of finding the demon that has appeared. I am confident you will find the issue if you use good order in your approach.  Either way I expect you will find some mechanical fault other than the ignition timing.

Thanks. That is all pretty much what I was thinking as well. Will open the cam chest and pull the head off tomorrow.

Quote from: SixShooter14 on May 20, 2024, 09:35:42 PM

Quote from: kd on May 20, 2024, 09:22:49 PMFor the above reasons (if it were me) I would stay on track and go one step at a time.  If you just tear it down it'll be hard to inspect everything with any real certainty of finding the demon that has appeared. I am confident you will find the issue if you use good order in your approach.  Either way I expect you will find some mechanical fault other than the ignition timing.

Thanks. That is all pretty much what I was thinking as well. Will open the cam chest and pull the head off tomorrow.

If you remove the throttle body (or carb) before the manifold, try to observe the oil film in the manifold if there is any.  You may be able to see if the cam overlap is contaminating the length of the intake manifold bore and how bad the oil contamination is.  Once yo get the head off, if your piston has any carbon on the top look for clean spots around circumference of the piston at the cylinder wall that will indicate engine oil bypassing the rings.

Quote from: kd on May 20, 2024, 09:51:37 PM

Quote from: SixShooter14 on May 20, 2024, 09:35:42 PM

Quote from: kd on May 20, 2024, 09:22:49 PMFor the above reasons (if it were me) I would stay on track and go one step at a time.  If you just tear it down it'll be hard to inspect everything with any real certainty of finding the demon that has appeared. I am confident you will find the issue if you use good order in your approach.  Either way I expect you will find some mechanical fault other than the ignition timing.

Thanks. That is all pretty much what I was thinking as well. Will open the cam chest and pull the head off tomorrow.

If you remove the throttle body (or carb) before the manifold, try to observe the oil film in the manifold if there is any.  You may be able to see if the cam overlap is contaminating the length of the intake manifold bore and how bad the oil contamination is.  Once you get the head off, if your piston has any carbon on the top look for clean spots around circumference of the piston at the cylinder wall that will indicate engine oil bypassing the rings.

will do. I pulled the air cleaner off and there was no oil in the carb or filter, but I didn't specifically look down the throat.

Quote from: kd on May 20, 2024, 09:51:37 PMIf you remove the throttle body (or carb) before the manifold, try to observe the oil film in the manifold if there is any.  You may be able to see if the cam overlap is contaminating the length of the intake manifold bore and how bad the oil contamination is.  Once yo get the head off, if your piston has any carbon on the top look for clean spots around circumference of the piston at the cylinder wall that will indicate engine oil bypassing the rings.

Got the head off and now I'm thinking it was the head gasket that went. There isn't really any wet oil on the piston or the intake valve, and no fresh oil on the exhaust valve after a week of sitting. But around the front of the gasket it was quite wet. The MLS gasket looks pretty ok and the head nuts were all good and tight on the studs (and no studs came out...

I haven't checked the cam/breather/pinion timing yet, that's next on the list.

thoughts and opinions?
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so my current thoughts are that the head gasket failed under the exhaust port near that front dowel. That's where the oil was sitting and the fire ring is pretty much black right there.

A) I got a few pops and puffs of flame through the carb when starting prior to the smoke. So, it might be a case of the ignition timing being off coupled with a cold engine?

B) It's also highly likely that when the oil pump failed and I rode the 2-ish miles home that it got too hot under that exhaust port. Then once the pump got to pumping and pressure returned, it blew into the cyl.

Quote from: SixShooter14 on May 27, 2024, 08:47:31 AMso my current thoughts are...

B) It's also highly likely that when the oil pump failed and I rode the 2-ish miles home that it got too hot under that exhaust port. Then once the pump got to pumping and pressure returned, it blew into the cyl.

welp, pulled the front cyl. and it's not pretty... Looks like she definitely ran dry for a bit. Time to pull the rear cylinder and off to the machine shop they go. Currently bored +0.010, will probably end up around +20 or 30.

On a positive note, the connecting rod has almost no side-to-side play. I'll give them a better look when the rear is off.


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That's ugly!   

I'm surprised it didn't seize.

OUCH !!