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John, I initially measured the shaft where the seal rides and it was 0.36. I found a U-cup seal that had an ID of 0.31 and OD of 1/2 and tried it and it’s extrmely tight because it gets additional compression when the shaft passes through. I was able to turn the shaft with it in place but it definitely has a lot of friction and takes some effort. I was also thinking that maybe it would loosen over time and after running the engine a bit. I’m really tempted to finish installing one on a spare test engine to see if it will work. This morning I was poking around again hunting for seals and found a listing that referenced a metric U-cup seal that was 9mm ID x 13mm OD. Unfortunately I haven’t found a source that actually carries them yet. I think this could be a really close possibility if I can actually find a source. Clint

David, Thank you for the links! This is awesome and will be extremely helpful as I start to work on this generator. Much appreciated! Clint

I’m thinking the reed valves look in pretty good shape, at least they don’t appear to be worn, bent or otherwise damaged. I think the compression release is working properIy, I push it in at initial start up and once it fires and sputters it seems the valve pops back out. If I go through the saw I’ll be sure to check it as well. Thanks for the link! Yes, that’s been the challenge. I found some 3/8 ID but they’re just ever so slightly too large. I’m still going to test them to see if when under some pressure they expand enough to create a seal but I’m doubtful because they’re too loose in a static state.

Thanks for checking, much appreciated!

Thanks John. I was wondering if perhaps that center band was covering up a seam. I’ll have to take a closer look.

I want to take apart my Tiny Tiger to do a full clean up and inspection. It’s not obvious to me how to separate the generator body from the PTO side of the engine. I see two long screws that connect from the rear but I don’t see a seam on the generator body itself where it would split in order to access the screws that are inside the shroud that bolt it to the engine. Does anyone have photos of how the generator body comes apart?

HeadExam, One of the seals that is hard to find is the induction shaft seal. The dimensions I get from a micrometer are 0.36” ID x 0.5” OD x 0.094 cross section and it’s a pretty simply U-cup shape. Clint Edit: Several posts replying about the 13A/13B shaft seals moved to new thread here: David, It is a little hard to start at first but once it fires I can generally get it to fire again after a couple pulls between the 1-2 seconds it dies. I poked a needle in the vent hole again this evening and was able to completely clear it. I then used a piece of fuel line and blew air into the fuel tank through the vent hole and the pressure exited through the hole so that appears to be working now. I think I’m going to tear the whole thing down and check the seals and fuel lines. I’m a little hesitant to go too far since the seals and gaskets aren’t available. I also don’t have replacement reed valves or any of the rubber gaskets that go between the reed valves and the case. This may end up on the shelf as a display piece only.

Thanks David! I will have to do some more sleuthing. I did find a glob of something on the fuel tank vent and was able to scrape it off and I stuck a needle into that tiny hole but that didnt change anything as far as running performance. I may need to do a more thorough cleaning of that vent hole. I haven’t gone through the saw to check all seals, gaskets and fuel lines so those are all definitely suspects. I appreciate the service bulletin references, those are quite useful. Amazing that you have access to all that stuff!

HeadExam, Thank you for the insights. That’s kind of what I was afraid of. I’ll have to look into the leak tester you referenced. Is that the same thing as the Mityvac 8500? You also have me curious regarding replacement seals. I’ve recently been hunting and trialing various seal options for the Compact engines. Have you ever looked into shaft seal alternatives for the 13A and 13B engines? I found a source that had some small U-cup seals that were very close but not quite right. I’m still trying to determine if I can get them to work. Clint Edit: Several posts replying about the 13A/13B shaft seals moved to new thread here:

I attempted to tune up the Mark II this afternoon with no success. After rebuilding the carb and resetting the H, L and Idle settings per the manual I thought it would fire up and at least idle for a bit. No such luck. All it does is fire and run for maybe 1-2 seconds. I also put in a brand new spark plug. So at this point I can’t keep it running long enough to do any tuning. Anyone have any thoughts on what might be going on? Given the condition of the saw I was hoping all the critical seals were still in ok enough shape but maybe they’re not and it’s getting air leakage or something. I was surprised when I opened up the carb that the original gaskets and diaphragms were still in good shape and pliable. The reed valves also looked nice and clean and flat so I’m thinking that part is also ok.

You’ve got that right, Factory, Wallfish and Webhead are incredibly knowledgeable and always very helpful! Their expertise and willingness to assist us newbies along the way is priceless. Clint

Nice saw, that should definitely clean up well. I got the carb kit off eBay. I went with a genuine Walbro K10-HDC carb kit. They’re pretty common and run anywhere from $9-15. Oregon and Rotary brand also appear to have kits. My saw has a Walbro HDC-14 model carb. I think the K10-HDC kit covers several of the HDC carbs. It was actually much easier to rebuild than I was expecting. This kit only came with gaskets, diaphragms, screens and needle valve. Hope that helps! Thanks HeadExam. I’ll have to try to find some of the Amsoil (that’s a synthetic correct?). I’ve heard great things about it. I’ve had good results so far with the Stihl oil, been using it at 32:1.

Finally had a chance to rebuild the carburetor on my Mark II chainsaw. Got it to fire but it needs a lot more adjustment and fine tuning. Operators manual calls for 16:1 gas to oil ratio - has anyone run these with the 32:1 ratio or am I better off mixing a specific batch for this saw? Overall the saw looks to be in pretty decent shape. Now that I know it can run I might tear it down for a full cleaning and to make sure everything is correct.

Ahhh, that make sense. I had to go look at that Bridges link again - that’s a really neat drill!

Great point John. I plan to have these mostly on the shelf and the occasional short run for fun so probably no need to worry about adding any oil, especially since as you point out it will likely just leak out. Thanks!

I’ve been using Lubriplate 105 grease on all the gear cases I’ve opened up so far. I’m also wondering if it would be good to add a little oil to help make sure the grease doesn’t get spun out of the teeth to the edges of the case and remain there. Has anyone else done a grease/oil mixture? If so, what amount and viscosity? I was thinking of adding a teaspoon or so of APG 90 gear oil (like what is used in the gear box of a small high power outboard) or would it be better to use a lower viscosity engine oil? I recall a posting from a David where one of the O&R drills called for using oil in the gear case.

Ha, that’s awesome - great find!

Thank you David! That looks like the grooved side of the seal is facing out away from the engine. I just finished opening up the engine again and flipped the seal around. I’ll see if there is any noticeable difference in how it runs. Thanks again for all the help! Clint

I just worked on an engine that had the induction shaft seal installed with the grooved side of the seal facing out away from the engine. Was this incorrect? It looked to be the original seal. I’m also a little confused about if the induction side of the engine is pressurized or if it creates a vacuum and sucks air. I’ve read multiple instances where people report oil and grease from gear boxes being sucked into the engine when the induction shaft seal fails. If this is true it would seam to me that the induction housing and seal are maybe under sort of a vacuum. Am I misunderstanding how this is supposed to work? Has anyone else come across a seal with the grooved side facing away from the engine?

You’ve got technical info on everything... interesting, in the drawing part F-141-1 looks slightly different from F-141. My generator looks to have had all F-141 feet. I’m planning to find some sort of rubber bushing or other rubber grommet to use in the hole where F-141-1 is shown. The F-141 foot that was there didn’t actually make contact with the generator, it was too low profile. Maybe I can find something that has just a little more height and will actually work to dampen vibration.

Fortunately there were 3 of the feet on the rear. I took the center one and moved it to the front corner. I’ll find a simple rubber grommet to put back in the rear middle hole that sits right under the main generator. I wasn’t sure about the handle, just didn’t look right and I debated on flattening out. I decided to go ahead and do it and I think it looks better that way.

I was finally able to work a deal on this Tiny Tiger and add it to my collection. It’s in need of a serious clean up. It has a couple obvious issues that I think I can address. It’s missing one of the little rubber feet on the base and the handle is slightly bent/twisted. I should be able to flatten that back out. The gas tank is a nasty mess inside, serious varnish and gunk built up. It still had what looked and smelled to be 50 yr old gas and varnish still in it... Otherwise it looks like it should clean up well. How well it will run who knows....

FYI, in case anyone is looking for an old chainsaw service manual that covers the O&R Ford chainsaws as well as the Orline, this 4th edition has a section on both. It also includes a couple pages on the model that has the larger 20 engine.

Wow, that’s incredible, way better than I even imagined! It looks like something from Terminator II... Thats an interesting carburetor as well. Thanks for posting the photos!

Good to see you back on Webhead! Can you post some photos of your chrome saw, I’m still very curious to see that one.