Removing 175 SL Wrist Pins

[DesertRat54]

Happy New Year to the Collective, and here's hoping that Santa brought you all the Hodaka goodies you wanted. For those of you with 175s, you're no doubt aware of the weird wrist pins that you encounter when changing out the piston. Well, that's where I am. How do I remove these wrist pins? will I need a tool that I'm not familiar with, or can I do this with just the typical shop tools? If this is some sort of PABATCO-inspired intelligence test, I've clearly failed.
Bill in VA

[thrownchain]

They do make a wrist pin removal tool, kinda of a universal application tool. Are you doing a complete rebuild or just renewing the piston?

[Bullfrog]

I haven't even seen a 175 wrist pin in over 40 years, but I don't see anything unusual in the Illustrated Parts List. So . . .

1. Heating things up to "spit sizzle" temp will likely free things up so the wrist pin will just slide out. Of course working with "spit sizzle" hot parts can be sort of difficult, so . . .
2. Get a piece of plastic pipe with a larger ID than the OD of the wrist pin - length must adequate for the wrist pin to fit all the way inside of it. Get a long screw/bolt with a head smaller than the OD of the wrist pin. Insert the screw through the center of the wrist pin AND the plastic pipe. Put a fender washer and nut on the threaded end of the screw/bolt. Tighten the nut to pull the pin into the plastic pipe.

Ed

[Bill2001]

What Ed says-- heat the piston or make a pin-press tool. Resist the temptation to tap the pin out while holding the piston-- chances are that the rod will get bent.

[DesertRat54]

Thanks, guys. I think I wasn't clear, though (my bad). It's the circlips that are giving me trouble, not the wrist pin itself. There are three "blades" to each circlip. For the simple "ring" type, I just press a sharp pointed punch behind the circlip, and it just pops out. It doesn't look like I can do this with these. Am I missing something?

And as of tonight, I have another problem: removal of the flywheel. It's an original motor that's never been apart, and I think there's some of that good ol' eastern mid-Atlantic humidity-induced rust in there. I had to take the motor to a local shop just to get the flywheel nut off because my impact driver and air tool weren't stout enough. I'm using the standard Hodaka removal tool with the three screws. I've shot PB Blaster into the flywheel recess, hoping that it'll soak down in and around the crank shaft (the motor is sitting on its side on the bench). So far, it's tighten, tap, tap, tap. Tighten, tap, tap, tap, etc. I've heated the flywheel collar as well. It's still stuck. I've left it soaking for the night; maybe tomorrow things will go better.

Thanks again,
Bill in VA

[thrownchain]

Is this a spiral loop? If it is you have to find the end and spin or unwind it out of there, not hard to do.

[taber hodaka]

Bill I have a small bend on my flywheel puller and a mushroomed head on it. I hit it with a 16oz hammed a very sharp blow, no tap tap. I have never had a problem, probably 100+ engines--------------Clarence

[Bullfrog]

. . . the power of multiple "spit sizzle" hot-to-"garage cold" cycles should not be discounted. I always re-apply my penetrating oil of choice during each heating cycle (so the interface is "wet" when the cool down starts). If you are in a rush, two, three or four hot/cold cycles might be achieved in a day. If not in a rush, overnight cool downs with a hot cycle in the morning can get you there in a few days. Those hot/cold cycles severely stress the common law marriage bonds between the flywheel hub and the crankshaft.

"Spit sizzle" hot is a good safeguard. The magnets and "potting material" around them won't be damaged at all if you stop heating as soon as you reach "spit sizzle" (OK, OK, spray bottle sizzle IS a bit neater )
Ed

[MWL]

Bill
Be sure to use the strongest graded bolts you can find for the flywheel. Standard bolts will stretch. I had the same problem with a 250. Never got the flywheel off. Good luck!
Mike

[racerclam]

I have had to enlarge the bolt threads to 8mm before to get enough strength to pop it off even with wack wack of hammer aand I always use a bit of anti seize on the taper for re assembly

Rich

[DesertRat54]

Thanks, gentlemen; all good suggestions. Ed, I feel better now that you say the cycling could take days. I'm not in a real rush to get the flywheel off, but it'd be nice if I could get it loose before June. The upcoming snow storm should help with the cold cycle... Mike and Rich: Ten-four on the bolts. I have also broken bolts with this very same puller on a 250 SL some years back. Clarence, I don't quite understand the "small bend" in your puller, but I have whacked the bolt head on my puller pretty good after heating the flywheel. I'll try it again tomorrow along with more heat and penetrating oil.

I've heard that distilled (?) apple cider vinegar will go after rust. It turns out that my wife has some, so I could try that, too.

Bill in VA