Parts sourcing - Top-End Rebuild?

[Rob Frankham]

Can't remember from earlier in the thread whether you have replaced the pushrod rubbers...

If they are new, it is quite normal to have to pull last couple of mm up using the head nuts to compress the rubber. From the image, I would say that's probably on the limit of what I would want to try to pull up. Go carefully and if the nuts get too tight, or if tightening the nuts makes no difference, back off and find out what is causing the obstruction.

If the rubbers aren't new, that's too much to pull up and needs investigation.

Rob

[gspd]

Can't remember from earlier in the thread whether you have replaced the pushrod rubbers...

Are you sure you are using the correct pushrod seals?
r65 seals differ from other models.
It would have been a good idea to clean the block while it was apart, makes it easier to spot a leak later.
Assure yourself that the base o-rings are lightly oiled and not twisted.
Be sure the head gaskets are the right way around, the pushrod tube holes must align.

[Tom H Ca]

I don't know if this will help.

On my /5 with new push rod tube rubbers, the cylinder was held way out like yours. At the time I didn't know that the ring on the push rod tube was adjustable, it could very firmly slide on the tube. Slid it back, installed cylinder and then carefully tapped the ring down to the rubber and a bit more. I did not have the special tool, made do with a flat nose punch.

I do not know if the ring is adjustable on your engine.

Tom

[kmisterk]

Can't remember from earlier in the thread whether you have replaced the pushrod rubbers...

Rubbers are replaced here. New Pushrod seals have been installed on the pushrod tube ending before this.

I do not know if the ring is adjustable on your engine.

I was informed by my parts supplier that bikes from my era are "silver welded" there. I checked, and there is zero movement on that part of the pushrod tube.

Are you sure you are using the correct pushrod seals?
r65 seals differ from other models.

I'm 95% sure they're the correct ones. From what I can see from the images you posted, the ones *not* for my r100 don't have nearly as exaggerated ridges on the section that inserts into the block. Also, I was assisted by an "airhead guy" at the shop I went to for parts (SoSo Cycles in Fife, WA, USA) that seemed quite familiar with these motors and knew a good deal of information that lead me to be pretty confident in his recommendations, for the most part.

It would have been a good idea to clean the block while it was apart, makes it easier to spot a leak later.

I still can. I was attempting to mount the cylinder and head but stopped when I couldn't get it flush without cranking it down. I wasn't yet ready to put the valve rocker assemblies back together and wanted verification on whether it's normal for new pushrod seals to prevent pressing flush like what is shown in the pictures above.

Assure yourself that the base o-rings are lightly oiled and not twisted.
Be sure the head gaskets are the right way around, the pushrod tube holes must align.

Base O-Rings as in the o-rings around the spigot of the base of the cylinder? I applied some grease to it for the sake of seating in its fitting correctly on the base of spigot.

Head gaskets are not symmetrical, and are easy enough to line up to the same shape of the two surfaces where the cylinder meets the head. I'm 99.9% sure this isn't an issue, especially considering its shape. Or are you referring to making sure the correct face of the gasket sets against which component of the engine? Like, flipping it like a coin from the front-side to the back side?

related question:

I've heard that some mechanics use a sort of non-setting sealant (such as Hylomar Blue) at the base where the cylinder meets the body of the engine. if I replaced the o-rings on the spigot, is this necessary or recommended?

[gspd]

For some reason I was thinking you had a r65...

I was attempting to mount the cylinder and head but stopped when I couldn't get it flush without cranking it down. I wasn't yet ready to put the valve rocker assemblies back together and wanted verification on whether it's normal for new pushrod seals to prevent pressing flush like what is shown in the pictures above.

It's normal to a certain degree. The seals should be under some tension, but not squashed to the point of being distorted. It's possible that in the past the pushrod tubes were knocked deeper into the block to compensate for hardened leaking seals. They might need to be knocked back out to fit the new seals.The other end of the push rod tubes should be approximately 1/8"* below the head gasket surface. You can tap them in further once all is buttoned up if there isn't enough pressure on the seal. (* guesstimate)

Base O-Rings as in the o-rings around the spigot of the base of the cylinder? I applied some grease to it for the sake of seating in its fitting correctly on the base of spigot.

I've heard that some mechanics use a sort of non-setting sealant (such as Hylomar Blue) at the base where the cylinder meets the body of the engine. if I replaced the o-rings on the spigot, is this necessary or recommended?

I just moisten them with a bit of oil, but a bit of grease might work. I personally never use sealer, I just lightly coat the base and top stud o-rings with a bit of oil, but everything has to be immaculately clean if you don't want any leaks.

Head gaskets are not symmetrical, and are easy enough to line up to the same shape of the two surfaces where the cylinder meets the head. I'm 99.9% sure this isn't an issue, especially considering its shape. Or are you referring to making sure the correct face of the gasket sets against which component of the engine? Like, flipping it like a coin from the front-side to the back side?

The head gaskets are on correctly if the pushrod holes in the gasket align with the holes in the barrel. I've seen them wrongly installed in the past.

Question(s) -
Did you install the oil filter shim and o-ring correctly?
Did you spin the crank before installing the con rods to confirm oil flow at both crank journals?

Suggestion-
Start the engine BEFORE installing the exhaust headers and valve covers just to be sure oil is dripping from all 4 rockers.
Saves a lot of time if something isn't right and allows for quick recheck of valve lash after running.

[melville]

I turn it over, plugs out, until I see oil from all four rockers:

[kmisterk]

For some reason I was thinking you had a r65...

(Whoops)

It's normal to a certain degree. The seals should be under some tension, but not squashed to the point of being distorted. It's possible that in the past the pushrod tubes were knocked deeper into the block to compensate for hardened leaking seals. They might need to be knocked back out to fit the new seals.The other end of the push rod tubes should be approximately 1/8"* below the head gasket surface. You can tap them in further once all is buttoned up if there isn't enough pressure on the seal. (* guesstimate)

I'll take a look at the push rod tubes and double check.

I just moisten them with a bit of oil, but a bit of grease might work. I personally never use sealer, I just lightly coat the base and top stud o-rings with a bit of oil, but everything has to be immaculately clean if you don't want any leaks.

Alright, I'll double/triple check the surfaces. Might still have some scum on the surface of the engine body where the cylinder meets the engine block.

The head gaskets are on correctly if the pushrod holes in the gasket align with the holes in the barrel. I've seen them wrongly installed in the past.

something for me to verify when I get back to the bike this afternoon.

Question(s) -
Did you install the oil filter shim and o-ring correctly?
Did you spin the crank before installing the con rods to confirm oil flow at both crank journals?

the engine is currently dry. I am applying oil to any oiled surface (IE the inside of the conrod bearing shells where they touch the journal) as I reassemble, but there is currently no oil filter, o-ring, or shim installed. The oil filter cap is currently no installed, and is awaiting later use. I've already torqued and installed the conrod bolts, and I don't want to loosen them. However, I still have the cylinders and heads, etc., all still largely disassembled. Is this something I should check before continuing?

Suggestion-
Start the engine BEFORE installing the exhaust headers and valve covers just to be sure oil is dripping from all 4 rockers.
Saves a lot of time if something isn't right and allows for quick recheck of valve lash after running.

This is the plan. If there is a blockage in the oil flow to the conrod bearing shells, will it have an effect on oil delivery to the valves?

I turn it over, plugs out, until I see oil from all four rockers:

This looks to be what GSPD suggested in his last sentances on his most recent post, but in a slightly different way.

[gspd]

I've already torqued and installed the conrod bolts, and I don't want to loosen them. However, I still have the cylinders and heads, etc., all still largely disassembled. Is this something I should check before continuing?

The exact cause of the failure is still unknown, let's hope it was just a loss of pressure at the filter from a bad (white) o-ring.
I suggested checking for oil flow before installing the rods, all you can do now is cross your fingers...or take it apart again.
Whatever you do, DO NOT SPIN THE ENGINE WITH THE RODS HANGING. You'll scrap the block.

If there is a blockage in the oil flow to the conrod bearing shells, will it have an effect on oil delivery to the valves?

NO. It won't affect flow to the rockers.
If for some reason there is no oil flowing to the con rod big end(s), you'll only know when it starts knocking.

[kmisterk]

The exact cause of the failure is still unknown, let's hope it was just a loss of pressure at the filter from a bad (white) o-ring.

I suggested checking for oil flow before installing the rods, all you can do now is cross your fingers...or take it apart again.
Whatever you do, DO NOT SPIN THE ENGINE WITH THE RODS HANGING. You'll scrap the block.

The rods are currently suspended by zip ties in a way that will never let the con rods touch the block at any point. However, I’ve put it back into neutral for the purpose of taking it to some gravel to wash the oil off.

Your concern about the flow through the crank journal worries me. It’s almost worth scrapping these bolts, grabbing some new ones, for the purpose of taking them off and testing the flow.

Remind me again how I can do that?

NO. It won't affect flow to the rockers.
If for some reason there is no oil flowing to the con rod big end(s), you'll only know when it starts knocking.

Yep. This basically settles it for me. I’m gonna take the con rods back off and grab new bolts. It’s worth it in my eyes.

[gspd]

Your concern about the flow through the crank journal worries me. It’s almost worth scrapping these bolts, grabbing some new ones, for the purpose of taking them off and testing the flow.
Remind me again how I can do that?
Yep. This basically settles it for me. I’m gonna take the con rods back off and grab new bolts. It’s worth it in my eyes.

The easy way is to remove the rods and spin the crank with the starter motor and make sure oil comes out of both journals.
It might shoot out all over the place so you should wrap a piece of rag loosely around each journal (held with tape or a zip tie) to minimize the mess.

-or-
the redneck way...
if you want to save the time and expense of getting new bolts...
you can try this first, it should work but I've never actually tried it.
Be absolutely sure to avoid any metal on metal rod to block contact.
Remove pistons,
wrap the small ends and middles of the conrods in duct tape padded with rags,
protect the top and bottom of the holes in the block with duct tape and rags,
remove the oil pressure switch,
put the bike in 5th gear and CAREFULLY and SLOWLY rotate the back wheel to turn the crank until oil comes out the oil switch hole. This will assure that the oil pump is primed. It might take a while if all the oil passages are empty.
Then, put the switch back in and continue rotating the wheel until you can confirm that oil is oozing out around both big ends.
Be absolutely sure to avoid any metal on metal rod to block contact.