Ohlsson & Rice: Orline Mark II Chainsaw

[CNew 404]

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. 

Edited July 13, 2019 by CNew
Typos

[HeadExam 1,783]

Using modern 2 stroke oil you can safely run them at 40:1 or even 50:1. I use Amsoil Saber at 50:1  in old saws(1965-1975) and 100:1 in my new big Husqvarna strimmer for the last year or so. Amcoil maybe the best two stroke oil out there. Very nice shape.

[JUST O&R 237]

JUST GOT ONE LIKE THAT A FEW MONTHS BACK. NOT IN THAT GOOD OF SHAPE BUT SHOULD CLEAN UP. WHERE DID YOU GET THE CARB KIT

[CNew 404]

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!

7 hours ago, HeadExam said:

Using modern 2 stroke oil you can safely run them at 40:1 or even 50:1. I use Amsoil Saber at 50:1  in old saws(1965-1975) and 100:1 in my new big Husqvarna strimmer for the last year or so. Amcoil maybe the best two stroke oil out there. Very nice shape.

 

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.

[JUST O&R 237]

THANKS THIS ONE MIGHT BE A LITTLE SIMPLER THEN MY OTHERS. THE DIAPHRAGMS FOR MY OLDER ONE ARE HARD TO FIND I THINK THE # IS 400102.

DO YOU KNOW WHERE I COULD FIND A FEW?

[factory 487]

2 hours ago, JUST O&R said:

JUST GOT ONE LIKE THAT A FEW MONTHS BACK. NOT IN THAT GOOD OF SHAPE BUT SHOULD CLEAN UP. WHERE DID YOU GET THE CARB KIT

 

Doesn't look too bad, it should clean up well, just be aware the decal stickers can be easily damaged by cleaning on these later O&R tools.

 

@Webhead may still have some original O&R specific carb kits for these saws or a modern kit can be bought as CNew said.

 

51 minutes ago, CNew said:

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.

 

I'm sure we have mentioned this before, Amsoil only make synthetic oils for 2-stroke engines. Will it be OK with the seals & that unobtainium reed valve?

 

David

[JUST O&R 237]

I WOULD LOVE T HAVE AN ORIGINAL . HOW DO I GET ONE ?

[factory 487]

41 minutes ago, JUST O&R said:

THE DIAPHRAGMS FOR MY OLDER ONE ARE HARD TO FIND I THINK THE # IS 400102.

 

That is an O&R or AEP number, you will only find new-old-stock of those as AEP (Advanced Engine Products Inc) closed down in 1978.

 

Edit: Where did you find that number (#400102)? As it is a replacement carb diaphragm assembly for the smaller 1HP Compact & Series 13 engines, no use whatsoever for the Series 20A engine used in these chainsaws.

 

25 minutes ago, JUST O&R said:

I WOULD LOVE T HAVE AN ORIGINAL . HOW DO I GET ONE ?

 

This may help with part numbers for the O&R repair kits if Webhead still has any (send him a private message).

 

David

[JUST O&R 237]

THANK YOU. I HAVE BEEN LOOK AT YOUR POSTS FOR A WHILE BEFORE I JOINED. YOU SEEM TO KNOW EVERYTHING ABOUT O&R. KEEP UP THE GOOD WORK I WILL PROBABLY NEED MORE HELP.

[factory 487]

Glad to help, see my edit in the last post about part #400102 which is not for the Series 20A engine used on these saws.

 

David

[JUST O&R 237]

NO THAT # I THINK FITS A FEW OF MY OLDER PROJECTS I'M NOT NEAR THEM BUT I THINK ONE IS A TYPE 241 AND ANOTHER IS A C MODEL ON A CIRCULAR SAW. 

THIS ARE THE ONE I CAN'T FIND.

[factory 487]

Ah I see, you would have been best to post that request in another more relevant thread, the carb rebuild sticky thread gives info on where to find reproduction carb diaphragms for the smaller 3/4HP to 1HP engines. I will add the info about part no #400102 there.

 

David

[JUST O&R 237]

SORRY NEW AT ALL THIS THANKS TERRY

[CNew 404]

1 hour ago, JUST O&R said:

THANK YOU. I HAVE BEEN LOOK AT YOUR POSTS FOR A WHILE BEFORE I JOINED. YOU SEEM TO KNOW EVERYTHING ABOUT O&R. KEEP UP THE GOOD WORK I WILL PROBABLY NEED MORE HELP.

 

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

[Wallfish 698]

6 hours ago, JUST O&R said:

NO THAT # I THINK FITS A FEW OF MY OLDER PROJECTS I'M NOT NEAR THEM BUT I THINK ONE IS A TYPE 241 AND ANOTHER IS A C MODEL ON A CIRCULAR SAW. 

THIS ARE THE ONE I CAN'T FIND.

Send me a private message with your name and address. I have some diaphragms available. .

[factory 487]

7 hours ago, JUST O&R said:

SORRY NEW AT ALL THIS THANKS TERRY

 

It's OK, I or any of the other Mods can move posts to other threads if needed, I've put the service bulletin about part #400102 in the carb thread, hope it helps.

 

David

[CNew 404]

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.

[HeadExam 1,783]

2 hours ago, CNew said:

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 may have an air leak in the crankshaft seals, common issue on these old saws and why many get tossed, no seals available for many of these old saws. Air leaks in the carb or crank seals are often the cause of this issue. You can use a leak tester like the mity mite 8500 to determine whether you have a leak in the carb, by blocking the intake off with a plate and also making a plate with a stem to test crankcase pressure. I have diagrams on these testing plates if you need them. I also have a large database for new replacement seals by size and cross referenced to new part numbers.

[CNew 404]

On 7/15/2019 at 1:43 AM, HeadExam said:

You may have an air leak in the crankshaft seals, common issue on these old saws and why many get tossed, no seals available for many of these old saws. Air leaks in the carb or crank seals are often the cause of this issue. You can use a leak tester like the mity mite 8500 to determine whether you have a leak in the carb, by blocking the intake off with a plate and also making a plate with a stem to test crankcase pressure. I have diagrams on these testing plates if you need them. I also have a large database for new replacement seals by size and cross referenced to new part numbers.

 

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:

 

Edited July 20, 2019 by factory
Updated

[factory 487]

21 hours ago, CNew said:

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.

 

Is it difficult to start as well?

 

Here is what the service bulletin has for 'will not idle'  (HeadExam has already mentioned most of them);

 

 

Edit:

Also found the service manual mentions blocked fuel tank vent, as a possible cause of only running for a short time.

 

 

Or there may be a cracked fuel line to the carb.

 

David

[CNew 404]

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!

[Webhead 95]

The fuel tank vent has been the problem many times for me. I always try to run it with the fuel cap loose.

[CNew 404]

On 7/15/2019 at 11:57 AM, HeadExam said:

If you can use a micrometer and give me the sizes of the seals and type/number of lips, I may be able to cross reference it to a stock seal.

 

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:

 

On 7/15/2019 at 7:26 PM, factory said:

 

Is it difficult to start as well?

 

Here is what the service bulletin has for 'will not idle'  (HeadExam has already mentioned most of them);

 

 

Edit:

Also found the service manual mentions blocked fuel tank vent, as a possible cause of only running for a short time.

 

 

Or there may be a cracked fuel line to the carb.

 

David

 

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.

Edited July 20, 2019 by factory

[Wallfish 698]

Think there might be some 20A parts in the stuff I'm sending you. maybe some gaskets but I didn't go through it very thorough.

  I do have a couple of NOS reed valves for those in my parts stash.

Is the compression release closing?

 

[CNew 404]

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.

8 hours ago, HeadExam said:

You might look at this catalog, I haven't found any seal of any type that is .036 ID all are .031 or .040

https://www.skf.com/binary/21-318140/810-701_CRSeals_Handbook_FULL_Apr-2018_rv1.pdf

 

 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.