All,

I thought it might be interesting to see a picture of that 4th cylinder stud bolt, which was so hard to get out.
As you see, at the top of the thread there is evidence that the stud was screwed so forcefully into the crankcase, that there is galling of alluminium on to the stud. No wonder it was stuck like that.

It beats my imagination why anyone would do this. The way I think about it, any tension applied to the threads this way, subtracts from the available tension total that can be applied to the stud from the top end, before the threads gets pulled out of the crankcase.

My comments about Mikes extractor tool was not meant in a derogative way, as you all know I am i awe of mikes work, and copy it all the way. It is a great tool, and I will use it to reseat the studs, while making sure they are not over tight.

Here is the bronze nut seen from the other side revealing that a o-ring is used to seal off any oil leak. On this head casting, there was too little material at this place, so I had to build up with JB-Weld around a countersunk allen screw, which's head, machined, became the mating surface of the bronze nut

Finn, looks like you are making good progress.

Can you elaborate on: "bend the stud to get the head off"  How did you do that?

Regarding your comment :  "It beats my imagination why anyone would do this."  I don't think that someone intentionally drove that stud in so hard that it galled.  When you go to tighten your head nuts you will probably notice that as you approach final torque, the stud starts to wind up and spring back when you release the torque wrench.  The nuts develop so much friction in the threads that they start to grab the stud.  At that point, the stud starts to rotate with the nut.  That's why it is so important to make sure that the threads are perfectly clean and that the nuts rotate freely for the full length of the threads.  As a minimum, the threads, bottom of the nut, and copper washers should be well lubricated with oil.  I personally prefer oil on the threads and bottom of the nuts, nickel based anti-seize on the bottom of the copper washers (RF, LF, LR), and Teflon sealant on the top and bottom of the copper washer on the right-rear.  Even when they are cleaned and lubed properly, the nut still tends to grab the threads on the final phase of the torque procedure.

Regarding this comment: "It is a great tool, and I will use it to reseat the studs, while making sure they are not over tight."  The cylinder studs should only be threaded into the engine case by hand.  You only need to make sure that they are fully engaged (about 15 to 16 turns).  Use your fingers, no wrenches.  If properly cleaned they should thread all the way in by hand.

The o-ring groove in your "bronze counter nut" looks to me like it is too narrow.  I think the groove needs to be a bit wider to allow room for the o-ring to spread out.  Pretty cool the way you incorporated the socket head cap screw along with the small holes for a pin spanner.  

I suspect that wear on your rear chain guide is due to over-extension of the tensioner plunger.  The stock tensioner plunger becomes unstable as it extends further out of the aluminum body.  The toothed rack aggravates the condition.  Not only does the plunger start to move up & down, it also starts to allow movement right & left.  Since the plunger is used to restrain the right & left movement at the bottom of the chain guide, the loss in rigidity caused  by the over-extension allows the guide to start rubbing on stuff (chain, primary drive gear, etc.).  

Some of us have switched from the plunger with the toothed rack to a plunger with no rack.  We make the plunger longer and set it up such that it only has about 1.0 to 1.5 mm of back travel.  That system is much more stable and works excellent.  I periodically check mine and in the event that the back travel exceeds 1.5 mm I simply adjust the jack screw to restore correct back travel.  I check mine every oil change (3500 miles) and in the last 20K miles it has not needed adjustment.  With a new rear guide, you would probably need to adjust it a few times while the rubber guide beds in, then it just seems to never need much attention.

I believe Dave recently did a post on how to make one of these plungers without the toothed rack.  It's easy.

March 31 is just around the corner.  Wifey is watching you.  She expects a ride on April 1.  We are counting on you to hold up your end of the bargain.  

I was going to start a new thread about this, but, you guys have already brought it up so here goes.
At 80,000 miles I put one of Lancer's hardened cam chains on my bike, without changing the follower. The plunger was out quite a ways, and I thought it cause of the old follower.
Fast forward to 113,000 miles. I put one of Sneeze's clutch levers in and saw the plunger needed to go out to the second hole. I turned the plunger upside down to disable the pawl and put a plug spacer behind it to limit it to 1.5mm travel.
Fast forward to now with 153,000 miles. It was using oil, like 8 oz per thousand miles, so it's time for rings and valve guide seals,,,right? I pulled the head and jug off in the frame (by the way, those cylnder studs are m9x1.25 thread, RARE, I found nuts to fit off a Vespa crankshaft! had to get them from Italy!)
No measurable wear to the cylnder, no lip on top, and the new rings had the same end gap as the old ones! The valve guide seals LOOKED fine, but I changed them anyways. Where was the oil going???
The holes in the sides of the piston were clogged solid. Not allowing the oil to pass from the cylnder in or from the inside out to the cylnder.
I cleaned them out with a drill bit by hand and am in the process of putting it all back together now.
Back to the tensioner.
After 40,000 miles the slop had grown from 1.5mm to 6.5mm, waaaay tooo much. I swaped to a new follower, but the two of them side by side showed there was wear from the chain into the rubber, but the curve had not changed. I made a new plug to bring the plunger movement back to 1.5mm and am going to check it every 20k from now on. 1mm wear or so every 10,000 miles I can live with.
The first cam chain lasted 80k, I think without the pawl this one will last at least 120k.
So if you are willing to check the plunger every so often, (yea you have to pull the exaust, drain the oil, make a new spacer, and buy/make a new gasket,) a plug/spacer behind the upside down plunger SHOULD make the cam chain last longer.

YOUR RESULTS MAY VARY,,,A LOT!!!

FinnHammer wrote on 03/28/24 at 10:24:04:


The rocker shaft is retained by a bolt that goes in from the top and screws into the shaft.

"I start to realise that these studs are something very special, (stretch bolts) and I will use all the fancy lubricants that I have, to avoid any galling this time. I even have some silver powder based grease to avoid galling in stainless/stainless applications, so I think I will be allright."


Finn, I caution you against using thread lubricants other than the oil, Teflon sealant, and nickel based anti-seize that I specified.  That is especially important for the threads, which should be lubricated with clean engine oil.  Each lubricant has a unique coefficient of friction.  If you use a lube with a lower coefficient (like molybdenum), you will stretch the stud farther than desired because the nut will rotate more to achieve the specified torque.  You can take the stud to yield, or worse yet, pull the internal threads out of the aluminum case.

This old post provides details on stretching the studs.  Since the initial post, I have modified the procedure slightly to help prevent the terrible galling that occurs on the bottom side of the copper washers.  Instead of applying Teflon sealant to all four washers, I use nickel based anti-seize on the bottoms of three of the washers (RF, LF, LR).  You probably still want to use the Teflon sealant on both faces of the RR copper washer since it operates submerged in oil.  You don't want a leak.  You want to use the Teflon sealant specified in the old post.

So, clean oil on the threads on all four studs.  Clean oil on the bottom face of three nuts (RF, LF, LR).  Nickel based anti-seize on the bottom face of three copper washers (RF, LF, LR).  Teflon sealant on the top and bottom of the RR copper washer.  In the event that you don't want to mess with the anti-seize, you can use the Teflon sealant on all four copper washers in lieu of the nickel anti-seize, just like I did in the old post.  I currently use the anti-seize because it's easier to clean up.  They both seem to have identical coefficients of friction.  I achieve about the same stretch with either product.

This is the old post.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1576269113/12#12

The cylinder I have had 15K miles on the clock, and there was a slight step at the top due to wear from the top ring, this step was sitting 9mm down from the seating surface of the cylinder.
Since the top ring of the high comp. piston rides higher, and would therefore have to bump over this step, I had to hone the cylinder to the point where this step was removed.

I used one of those stupid spider hones, with 160 grit stones.

This is a look at the cylinder after the honing process was finished. If you look closely, the faint shadow of the step can be seen. But it cannot be felt with a fingertip.