Topic: Sandcast #97 restoration

[markb]

Excellent.  That's just the kind of logic I was looking for.  Thanks.   

[anders288]

Also I have been using Loctite 603 on my alt kits applied to the tapper keep it from slipping. My guess is Honda went up to 12mm 60 ft lbs because some alt.were slipping

[HondaMan]

Ah, where there's a will...

Watching your thread makes me feel all warm inside from knowing that my trusty K2 has always had good maintenance, so whenever I had to go inside I never have had to struggle with anything.

...except when I went to change the starter clutch this time, the first time in 138k miles...so, it has the new screws to accompany the new rollers and springs. Boy, they were stuck! Neither heat nor fire nor dark of solvent tank, impact wrench, or long night in the freezer would budge those babes! Turned out to be the tiniest bit of rust under the tapered portion of each screw, locking them securely into the cast rotor. It must have been a humid day in Japan that day when they made it?

Oh, that had to try your patience. 

tt

If I had realized what was making them so stuck, I would have drilled 3 tiny holes in the face of each screw, put in some penetrant, left it overnight, and hit it with a torch before trying again.

But, duh...I didn't think of rust!

[markb]

I loosened and retorqued the rotor bolt to 30 in. lbs.  I put on some Loctite thread locker just to be safe.  I feel better now.  While I was at it I thought it would be interesting to document some of the distinctions between the early and later sandcasts.  Since 97/E100 is so early it has most if not all of them.  Here is the early and later rotor bolt.  The early one is on the right.  It is an M10 x 1.25 x 45mm long with a plain 17mm hex head.  The later one is larger and has a finer thread.  It is an M12 x 1.0 x 53mm long with a 19mm plain hex head and is necked down near the head and has a thread locking patch on it.  Of course the cranks are threaded accordingly.  The 10mm rotor bolt is used on engines up to 1080.

[markb]

Now that the crank is in, on to the transmission.  The originals are in rough shape.  I’m not going to be able to keep everything original anyway so I going to use parts from a donor engine.


Same with the clutch.


My replacements look really good but since I don’t know the history of them I’m going to replace all the bearings including the needle bearings in the primary drive.  I got all the ball bearings from Yamiya for $100 including the shipping.  I couldn’t come close to that from the local bearing supply stores.  I bought the needle bearings separately for $12 apiece.

[markb]

Here is a distinction on the clutch.  The later engines have a one piece clutch center as shown on the left.  The early ones have a separate clutch plate that is held onto the center with a wire retainer.  The three pieces are shown on the right.  The early version went up to engine 1759.


Here’s a close up of the clutch centers showing the groove and the hole for the retainer on the early one.  I know why they changed the design.  The retainer is a PITA to install.  They are a discontinued part but I managed to find a couple so I bought them.  Good thing I did because I already broke one.  Before I break another does anyone have any advice for installing them?

[KayOne]

Interesting that the basket has no band. Wouldn't want to wind that Puppy up too much!

[MoMo]

Mark,  hopefully you mean 30 ft. lbs?....Larry

[markb]

Ooops.  Yes, 30 ft. lbs.

[markb]

I got it!  I tried another retainer and it went right in.  I compared it to the one that broke and it appears that the other one was too short.  Maybe from another similar Honda clutch?  The ends wouldn’t go all the way through the hole like in the picture.  By the way, that is a new clutch plate.  I also bought the other six plates, new friction discs, springs and lock washer.

[markb]

I finally had a significant amount of time to do some work over the weekend.  I was hoping to make some real progress for a change.  Not to be (as you will soon see).

I first decided to wrap up the oil pump.  I had the three sandcast bodies and bases hot tanked and ultrasonically cleaned.  There was a lot of thick sludge in the passageways and I wanted to make sure they were clean.  The early one still looks pretty rough but I decided to reassemble the other two.  The check valve holes were varnished up so I ran a 12mm reamer into them to clean them out and then polished them up a bit.  Then I picked the best sets of rotors and other parts from six pumps and measured everything (bores, OD’s, thicknesses, depths, feeler gauge clearances) to make sure all was in spec.  I used the cream of the crop for the pump I’m putting in E100.  Also new seals, springs and oil stopper valves for both. 


I liberally oiled everything and put them together.  The one slated for E100 went together perfect and feels great.  Then the second pump not so much.  I could feel a little catch at certain points when I rotated the gear.  Took it apart several times and re-inspected everything and even changed pins, rotor sets, etc.  I finally gave up for now and put a tag on it so I won’t forget and will get back to it later.  I probably should have just moved on right away since the second pump isn’t helping with this project but I’m trying to come up with a way to test them and it would be nice to do both.  Instead I ended up wasting the better part of the afternoon. 


So I decided to finish up with the main shaft and clutch.  Everything went well until I got to the clutch.  Somehow I ended up with the wrong (incorrect, they would still work but correct for later clutches) friction plates and clutch springs (too long).  I still haven’t figured out if I ordered the wrong ones or just got the wrong ones.  Sometimes it’s frustrating not being able to just finish something. 

[markb]

Ok it’s Sunday now and I figure I’ll tackle something easy.  I’ve got a couple of nice final shafts and gears (the original shaft, gear and bearings are one solid rusted piece) so I pull one out and put on new bearings.  I notice that someone has plugged the oil hole to disable the automatic oiler and decided to leave it that way for now.  I set it in place in the upper case and gave it a spin expecting it to be nice and smooth.  That would have been too easy.  The gear was definitely rubbing.  I pulled that shaft out to take a look.  Here’s a pic of the case.  You can see where someone (at the factory?) had done some grinding.  If you look to the right of that you can see a radial line where it appears the old gear was rubbing.


I kept looking at the manual and my other shafts just to make sure I put it together right.  There’s only two ways to put the gear on (it has a wider shoulder on one side than the other) and the other would make it worse.  I even tried one of my other shafts and gears hoping that would fix it.  Nope.  My head was getting sore from scratching it.  To be sure where it was rubbing I marked it up with a red sharpie and you can definitely see it.  So I got out the Dremel and took the crank and main shaft out and covered the mains (so I wouldn’t get grinding dust on them) and went at it.  I didn’t have the greatest tips and they kept loading up so it took forever.  I lost count of how many times I took the shaft in and out.  Every time I’d grind and remark it I would find another high spot. Finally it quit rubbing and I ground all over one more time for good measure and even then it really wasn’t much that I ground off.  So that’s a couple more hours I’ll never get back.  I hate to say it but after that I just didn’t feel like doing any more today.  I guess that’s what happens when you work with sand castings. I hope there’s more clearance on the other half. 

[Roach Carver]

Good lord, you are a more patient man than I am.

[HondaMan]

I finally had a significant amount of time to do some work over the weekend.  I was hoping to make some real progress for a change.  Not to be (as you will soon see).

I first decided to wrap up the oil pump.  I had the three sandcast bodies and bases hot tanked and ultrasonically cleaned.  There was a lot of thick sludge in the passageways and I wanted to make sure they were clean.  The early one still looks pretty rough but I decided to reassemble the other two.  The check valve holes were varnished up so I ran a 12mm reamer into them to clean them out and then polished them up a bit.  Then I picked the best sets of rotors and other parts from six pumps and measured everything (bores, OD’s, thicknesses, depths, feeler gauge clearances) to make sure all was in spec.  I used the cream of the crop for the pump I’m putting in E100.  Also new seals, springs and oil stopper valves for both. 


I liberally oiled everything and put them together.  The one slated for E100 went together perfect and feels great.  Then the second pump not so much.  I could feel a little catch at certain points when I rotated the gear.  Took it apart several times and re-inspected everything and even changed pins, rotor sets, etc.  I finally gave up for now and put a tag on it so I won’t forget and will get back to it later.  I probably should have just moved on right away since the second pump isn’t helping with this project but I’m trying to come up with a way to test them and it would be nice to do both.  Instead I ended up wasting the better part of the afternoon. 


So I decided to finish up with the main shaft and clutch.  Everything went well until I got to the clutch.  Somehow I ended up with the wrong (incorrect, they would still work but correct for later clutches) friction plates and clutch springs (too long).  I still haven’t figured out if I ordered the wrong ones or just got the wrong ones.  Sometimes it’s frustrating not being able to just finish something. 

I find that many of the pumps have become 'jealous' of their original assembly, and end up taking them apart many times before they go together smoothly. It's a little hard to explain, but I go at it like this: if it 'sticks' in one spot, I rotate to that spot, disassemble, and jump one (or the other) rotor one lobe in its position, then reassemble and try again. Enough times and it finally goes back together smoot again.

One place to look, for sure: the locator pins in the shaft get bent a little bit in many of them, particularly on the high-PSI side. If so, reinstalling with the bent end out will almost always ensure a smooth reassembly with less iteration.

[HondaMan]

Ok it’s Sunday now and I figure I’ll tackle something easy.  I’ve got a couple of nice final shafts and gears (the original shaft, gear and bearings are one solid rusted piece) so I pull one out and put on new bearings.  I notice that someone has plugged the oil hole to disable the automatic oiler and decided to leave it that way for now.  I set it in place in the upper case and gave it a spin expecting it to be nice and smooth.  That would have been too easy.  The gear was definitely rubbing.  I pulled that shaft out to take a look.  Here’s a pic of the case.  You can see where someone (at the factory?) had done some grinding.  If you look to the right of that you can see a radial line where it appears the old gear was rubbing.


I kept looking at the manual and my other shafts just to make sure I put it together right.  There’s only two ways to put the gear on (it has a wider shoulder on one side than the other) and the other would make it worse.  I even tried one of my other shafts and gears hoping that would fix it.  Nope.  My head was getting sore from scratching it.  To be sure where it was rubbing I marked it up with a red sharpie and you can definitely see it.  So I got out the Dremel and took the crank and main shaft out and covered the mains (so I wouldn’t get grinding dust on them) and went at it.  I didn’t have the greatest tips and they kept loading up so it took forever.  I lost count of how many times I took the shaft in and out.  Every time I’d grind and remark it I would find another high spot. Finally it quit rubbing and I ground all over one more time for good measure and even then it really wasn’t much that I ground off.  So that’s a couple more hours I’ll never get back.  I hate to say it but after that I just didn’t feel like doing any more today.  I guess that’s what happens when you work with sand castings. I hope there’s more clearance on the other half. 

This happened on and off until the K4 cases came along. So long as the chips were small, it didn't seem to hurt anything? Some folks say (said, back when) this had a lot to do with the dual-row output shaft bearing being installed, but that didn't stop it, either: you will see this same grinding witness on the K3 cases once in a while, with the dual-row bearings installed. I imagine it to be due to their casting processes until the K4 molds were finally perfected.

[HondaMan]

Now that the crank is in, on to the transmission.  The originals are in rough shape.  I’m not going to be able to keep everything original anyway so I going to use parts from a donor engine.


Same with the clutch.


My replacements look really good but since I don’t know the history of them I’m going to replace all the bearings including the needle bearings in the primary drive.  I got all the ball bearings from Yamiya for $100 including the shipping.  I couldn’t come close to that from the local bearing supply stores.  I bought the needle bearings separately for $12 apiece.

Can you use the inner bushings from the donor, and install them in the original gears? Just wondering...

What size of needle bearings fit in that early clutch?

Those "retainer" wire gadgets were in many of the early Hondas, the Twins. They were supposed to stop a rattle, but they also could cause clutch drag when stopped in gear with the clutch in: for that reason, many would get removed. For example: the CB/CL72 series (250 twins) had 3 of the wire retainers, one for the inner steel plate, one for the next steel plate after the first friction plate, and one for the 3rd steel plate as well. Removing the middle one would greatly improve the shifting when hot.

On the early K1, there is a clutch that has one of them on the last plate, although it is a slightly different design. My K2 has an early K1 engine in it (the bike came that way from Honda), and it had this top retainer: when hot, it would drag something fierce. I removed it and the problem went away, at about 9k miles. It's never had an issue since(!).

[markb]

Can you use the inner bushings from the donor, and install them in the original gears? Just wondering...

I thought about that.  Some of the gears are still rusted in place on the shaft.  I could probably get them apart with enough soaking, heat, etc.  It would be fun to claim the engine was all original parts, except bearings, seals, etc., but that isn't possible with this engine and I want to have a high level of confidence that everything is solid.  If not original it will at least be correct.

What size of needle bearings fit in that early clutch?

I assume you mean the ones in the primary sprocket.  They are 25mm ID x 32mm OD x 20mm wide.  I used an SKF #HK2520.

Thanks for all the interesting history and the oil pump tips.  This weekend if I get a streak where things are going better maybe I'll tear it apart and hopefully get it perfect.

[markb]

I’ve been thinking about the interference on the final shaft gear so I checked out the upper case from E1490 and I’m guessing this wasn’t a rare problem.  This case obviously had to be machined to provide enough clearance.

[HondaMan]

I’ve been thinking about the interference on the final shaft gear so I checked out the upper case from E1490 and I’m guessing this wasn’t a rare problem.  This case obviously had to be machined to provide enough clearance.

I see it quite a bit on high-mileage engines made before the K4. It's not nearly as dramatic as these, though!

[markb]

Here’s another interesting distinction.  The oil plug just above the oil filter housing and on the upper case is different.  On the left is the early one that is used up to E219.  The head measures approximately 16.5mm and it uses a packing with a square cross section.  The one on the right is on engines E220 and up and measures approximately 18.5mm and uses an o-ring.


While comparing the cases I took pictures of another distinction.  The early upper cases have cast bosses with untapped 6mm holes in the primary chain tunnel area.  It appears it could have been intended for mounting a tensioner or guide for the primary chain. 


Here’s a pic of a later case (E1490) without the holes.  It’s been observed that this change occurred somewhere around number 200.  Besides the plug change noted above there were other changes to the cases at 220.  I would guess the holes probably disappeared then too.

[markb]

Can you use the inner bushings from the donor, and install them in the original gears? Just wondering...

Mark, are you aware of any changes that were made on the early transmissions?  I just ran a accross some info where it says a change was made at #452 to make shifting better.  I looked at my shaft assemblies again and could not find any differences.  Could it be something in the drum or forks?

[markb]

I got my clutch friction disks and springs so I could finish main shaft.  I took both transmission shafts apart to inspect them and make sure they were assembled correctly and there are a lot of small holes that I wanted to make sure weren’t plugged.


Here’s another distinction on the clutch.  According to the parts manuals, up to engine 1759, the six inner friction disks had longer tabs than the one in the outer clutch ring.  I think they were the same disks used on the 450’s.  After 1759 there are a total of seven of the shorter tabbed disks.  There’s no reason that I could see that they couldn’t have used seven of the shorter tabbed disks on earlier engines.


I’ve got everything in the cases except for the kick starter and I’ll be ready to put the cases together.


Here is the way I aligned my primary chains.  This is how I have always done it but I have heard that some people prefer to jump a tooth on one strand to offset the links on the primary chains.

[greenjeans]

Mark is still my hero.  Would love to see this bike when you finish it.

[markb]

If I finish it. 

I have a nice block of time again so I want to try to button up the cases.  I got my kick start assembly in.  It took me a while to wrestle it in there but the bottom half is ready.


Then based on advice from several sources I staggered the primary chain so the top half is ready.


So then I’m double-checking everything and find that I’m missing the o-ring that goes around the big pin in the front of the cases.  I was sure I had one but couldn’t find it. Sometimes I wonder if this old girl ever wants to get back together.

[Greggo]

There should have been two of those in the Yamiya gasket kit, Mark.