Restoration of Sandcast #97

[kenhan]

In some way you should be able to balance it a little with readjusting the breakers gap with the plate(s) in another position.
Am I thinking wrong in that way?


/Ken

[kmb69]

I sure you did, but double checking, did you indicate the spark advancer to run true?

[markb]

I sure you did, but double checking, did you indicate the spark advancer to run true?

Actually I didn't.  Would it not run true because of a bent shaft?  The one I put in looked good but I will put an indicator on it.  I'm definitely going to take another look at it.  I'll try a different spark advancer and readjust the point gap too.  Like I said, I'm just not feeling good about it.

[kmb69]

Yes, that shaft doesn't have to be tweaked very much to cause similar issues. One can actually tweak it during installation even if it was straight to begin with. Of course, once you get it zeroed, NEVER turn the engine with that big nut that just sticks out there begging to be used to turn the engine. 

[markb]

Of course, once you get it zeroed, NEVER turn the engine with that big nut that just sticks out there begging to be used to turn the engine. 

Makes sense but does that mean that if you're doing a normal tuneup that you should remove the alternator cover and use the rotor bolt to turn the engine over?

[kmb69]

.....Because this nut is still planned for it? What is the reason??

Yes, pretty sure that was Honda's plan and I still do it but only with the plugs out. You have to make sure you are applying rotational torque ONLY and NO down or side pressure on that shaft. Most 23mm wrenches are quite long and it is very easy to "tweak" the advancer shaft on a strong motor with good compression. This was a tip we got from a Honda Service Rep back in the day when the bent shafts were first discovered to be causing timing problems. I am not positive, but I seem to recall a Service Bulletin regarding same. Honda changed that 6mm shaft with a thin nut to a 8mm flanged head bolt on the DOHC's which are electronic ignition and it holds the starter clutch on so maybe not a good comparison.

[4pots1969]

It is true that when known..This may seem obvious...!!
It is good know to avoid twisting the stem!!
Thanks,

[markb]

Yes, pretty sure that was Honda's plan and I still do it but only with the plugs out. You have to make sure you are applying rotational torque ONLY and NO down or side pressure on that shaft.

Excellent point on having the spark plugs out.  Mine are out.  And I agree on using care while rotating.  After indicating the shaft (and straightening if required) I will try again.  Thanks.

[markb]

I tackled my timing issue again.  A bent shaft seems the most logical so I rigged a setup to check it.  I first mounted the magnetic base to my cart but the engine supports aren’t very rigid so whenever I turned on the rotor bolt the indicator would wiggle.  I found a 7/16” bolt that went in tight on the right, upper engine mount hole.  Then I mounted the magnetic V-base on the bolt.  It doesn’t look very solid but I checked it buy pushing on the indicator from both sides and it always returned to the same spot.  So I found there was .025” run out.  I was able to straighten it to less than .001”.  I figured that had to be the problem.  I put everything back together, set the point gap and when I tried to set the timing it was worse!     I hadn’t put the nut on the spark advancer yet and found it had a lot of play on the shaft.  I put the nut on and tried again and still the same.  Now I was afraid I might have bent the shaft when I tightened the nut so I took it all apart and it still indicated less than .001”.  I put it all back together – still the same thing.   In the course of the next 5 hours I swapped sparked advancers, points, point plates and still couldn’t get there.  Finally by pushing the points and the points plate to one side of the clearance and reducing the point gap down to .012” I was able to get the points to break right at the F marks.  But I am still bottomed out in the slots for the timing adjustment.  It just doesn’t seem right but I don’t know what else to do.  It’s not like I haven’t done this before but I never had this issue.  Any ideas?

[markb]

After doing some searching on the SOHC4 site I found plenty of info related to what I am seeing.  Maybe I'm being too picky.  Like I said I would just feel better if I wasn't bottomed out in the slots.  Anyone know how many degrees between the T and F marks?

[Wayne]

I don't Mark, but I was just about to post a question. Did you happen to take a pic of the ignition side before you removed the breaker plate? I went through and didn't see one posted but I know you photograph everything. Would be interesting to see the indexing before disassembly.

[Steve Swan]

After doing some searching on the SOHC4 site I found plenty of info related to what I am seeing.  Maybe I'm being too picky.  Like I said I would just feel better if I wasn't bottomed out in the slots.  Anyone know how many degrees between the T and F marks?

Mark, i could give an answer based on my experience running into the same issue, but i'm going to ask the guys at the shop i worked at their experience, between the 3 of them, they have 130 years of experience.  i do know, working at the shop, when we had a unit that timing was set to the end of the slots, that's where the timing was set, but they may have other thoughts in addition.  I will see one of them later this week and ask.  does the service book give degrees between "T" and "F" marks ?  Would be easy enough to fit a degree wheel and measure the distance.

[markb]

I don't Mark, but I was just about to post a question. Did you happen to take a pic of the ignition side before you removed the breaker plate? I went through and didn't see one posted but I know you photograph everything. Would be interesting to see the indexing before disassembly.

I didn’t take a shot of the plate on the engine but here is what it looked like.  You can see where the washers were.  Definitely not at the end of the slots.

Mark, i could give an answer based on my experience running into the same issue, but i'm going to ask the guys at the shop i worked at their experience, between the 3 of them, they have 130 years of experience.  i do know, working at the shop, when we had a unit that timing was set to the end of the slots, that's where the timing was set, but they may have other thoughts in addition.  I will see one of them later this week and ask.  does the service book give degrees between "T" and "F" marks ?  Would be easy enough to fit a degree wheel and measure the distance.

Any suggestions are welcome.  I didn't see anything in the service manual about the degrees.  The only reason I was wondering was so I could estimate how close the timing was set.  What would be a reasonable tolerance, +/- 1 degree?

[markb]

Thanks for the info.  The reason the two advancers in your top photo are different is that the one on the right is assembled incorrectly.  The cam is 180 degrees off.  The mark on the edge of the cam should line up with the Hitachi logo.

[kenhan]

Hi Mark,
I noticed that you tried with differents points and plates so you should be able to exclude that.
Still one longshot though, if the little cam follower on the breaker arm is shorter than it should be, it will lift the breaker arm later and that would affect the position of the the plate. Vice versa if the breaker arm are longer than it should be. A longshot but I guess you consider everything at this moment.

/Ken