A butane torch, containers, some lead and my Graupner Wankel

Round lead fishing weights are suitable for this. Cut half and melt

https://www.amazon.com/dp/B0925TT936/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B0925TT936&pd_rd_w=sxcGd&content-id=amzn1.sym.46bad5f6-1f0a-4167-9a8b-c8a82fa48a54&pf_rd_p=46bad5f6-1f0a-4167-9a8b-c8a82fa48a54&pf_rd_r=6ZNAY4SK5QQQ28P9Q7EJ&pd_rd_wg=FCd7j&pd_rd_r=464289a5-8369-46e5-a146-ab5c827725eb&s=sporting-goods&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFZR1NVTjFQR1hKR08mZW5jcnlwdGVkSWQ9QTA4MTg1NjU1N0w0WE5TNFM0MDgmZW5jcnlwdGVkQWRJZD1BMDU3MjIyNDFFNlI1TVBRSEFFRk8md2lkZ2V0TmFtZT1zcF9kZXRhaWwmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

Thanks pman and Levent.  That's a thought, heat the counterweight with the lead in the holes.  A heat gun should not damage the counter weight but a torch might.  I will try that first.  

Hmm....just remembered, I used a torch to heat the counterweight to remove it from the crankshaft which melted the lead in the first place.  Now, if I don't burn the house down.  

Bob

My thinking was the heat gun would be less likely to discolor the metal, also provide some air movement to keep the vapors away from the user,
Don't breathe the vapors from the melted lead.......


                    Don

pman1111 wrote:My thinking was the heat gun would be less likely to discolor the metal, also provide some air movement to keep the vapors away from the user,
Don't breathe the vapors from the melted lead.......


                    Don

Thanks Don, but that ship sailed the first time. I had no idea that those holes were lead filled.

Probably will do it out in the garage with door and windws open. But thanks for the caution, I was going to do it at the kitchen sink. Fire/water you know.

Bob

Well, I cut the lead up into small pieces and tried to even them out between the four holes. Used all the lead that originally came out. Heated with the torch and paddled it around. Close enough but not perfect. Sandblasted (aluminum oxide media) it along with the heat sink ring and the muffler off the OS-30. Gives a frosted look that will be mitigated with a toothbrush and aluminum polish. Looks better than the stained mottled surface of before.

Again, sorry for the poor pictures. This Nikon does not tolerate my shake like the Olympus does. Last picture was when I layed the camera down and just pressed the take button.

If you need a little more lead, I'm sure you have an old shotgun shell to donate a few pellets to the project

pman1111 wrote:If you need a little more lead, I'm sure you have an old shotgun shell to donate a few pellets to the project

Yes, I have scattered a few of those pellets around the hills and valleys of Virginia and West Virginia.

It's coming along nicely.

Scratch another one off, it's done except for some time on a test stand.  Not holding out much hope, little to no compression but the fellow in the video, he had almost no compression either so we will see. More of an educational toy for me rather than a functioning engine.  

New 3mm hex heads from China (cheap) installed and cross tightened.  I had ordered #2's for the back case but too small, #3's are too big, but there is a 2.5mm should have ordered those too.  But I found that 2/56's cut to length screw right in so I used those.  Should help out when repairing my European locomotives too.



As received.





Not losing another ten dollar Woodruff.

OS uses M2.6 most of the time. I can't think of a time I've seen M2.5 in an OS. M2.5 obviously fits, but if at the low end of the tolerance can be tough on the threaded hole. M2.6 can be hard to find.

I used 2-56 in a metric application in a pinch just last week, but it was in place of M2.2. M2.2 has the same pitch as M2.5 and M2.6. M2.2 would have little to no thread engagement and be obviously loose in an M2.5 or M2.6 hole. Now 3-56 could be acceptable, if the proper screw isn't available. For a thread in aluminum, I would get the right fastener.

gkamysz wrote:For a thread in aluminum, I would get the right fastener.

When I lived in Japan, I was able to easily find all the metric hardware for my 1987 Suzuki LS650 Savage, that was my travel to work vehicle. Even bought hardware at the 100 Yen stores (equivalent to dollar stores in US, but much better quality items). Here, it took further digging and sometimes mail ordering. For bolts with nuts through an unthreaded hole, substitutes ANSI/ASE. Just too bad there isn't a Japanese Fastenal or McMasters available locally.

Some of my engines that used metric, I retapped the hole for ANSI. Where threads were stripped, retapped for next size up. However, the down side is needing end taps for short depth holes, which can be expensive, unless one is fortunate to have such available at their workplace.

I'm pretty sure that they were 2/56's, black they were mixed in with my naturals. I have 3/48's but these worked so well I just went with them. Back plate application, not much stress there. I saved two of the phillips head originals.

Misumi has any metric thingamathing you could ever want. Sometimes you have to wait and generally cost more than McMaster.

There are also the old (< mid 1960's?) obsolete Japanese threads which are hard to find. Only a few sizes didn't match the ISO standard. I think sometimes you find them on Enya ans OS. It's a problem with cars and bikes as well.

I can search, buy and send 2.5 or any size metric screws to you. If you want specify the size and send a photo of screws

The parts breakdown I have for this version doesn't list size and the part number didn't come up online at all. The back cover screws are listed as M2.6 in the later engines.

The odds of that hole being M2.2 are zero. If you have 2-56 in the M2.6, I'm quite surprised it didn't strip just snugging it up like the one I just tested did. I've never seen 3-56 in the wild.

Measure the diameter of the screw threads with a mic or caliper to figure out what they are. M2.5 and M2.6 can be hard to differentiate.

gkamysz wrote:The parts breakdown I have for this version doesn't list size and the part number didn't come up online at all. The back cover screws are listed as M2.6 in the later engines.

The odds of that hole being M2.2 are zero. If you have 2-56 in the M2.6, I'm quite surprised it didn't strip just snugging it up like the one I just tested did. I've never seen 3-56 in the wild.

Measure the diameter of the screw threads with a mic or caliper to figure out what they are. M2.5 and M2.6 can be hard to differentiate.

Thanks, when I get a chance I will remove the screws and compare the originals against the replacements.  I have a micrometer and I think the proper thread gages.  

If you're searching for 2.5mm or 2.6mm screws, try Microfasteners.com. They have screws in both thread sizes, lengths, head types and metals.
I have used them numerous times -- their pricing is competitive and shipping reasonable.

a--

andrew wrote:If you're searching for 2.5mm or 2.6mm screws, try Microfasteners.com.  They have screws in both thread sizes, lengths, head types and metals.
I have used them numerous times -- their pricing is competitive and shipping reasonable.

a--

Thanks Andrew, they do have 2.5mm's and assortments which I like. They are also located quite close to me in Easton Pa.

http://www.microfasteners.com/astmet-metric-socket-head-cap-screws..html