sachs dolmar 309-123 hybrid ;o)

[captain dangers]

I have had this project to do for the last couple of years and ive been putting it off and finaly thought sod it! I'm going to have a go ;o) the project in hand was to convert an old sachs dolmar 309 to a chainsaw with some parts I had lying over from a 123 with a knackered crank. I anted the tank off the 123 putting onto the 309 as the 309 is full of debris/muck as, although dolmar used to blank the oil filler cap off on the 309 they left the oil pick-up aperture open which just allows dust etc. to get into the tank. other parts to transfer from the 123 were as follows: oil pump worm drive, oil pump, oil hoes etc, sprocket, bearing, clutch, chain brake mechanism. I had to drill out the oil galleries on the 309 crank case as dolmar obviously didn't bother doing these in the casting process on the disc cuter batches, presumably to save £ ?

photos 1-2 are the 309 and the 123 donor saws .

 

[captain dangers]

tank and engine separated on the 123 & pulling the worm gear off the 123

 

[captain dangers]

tank/engine separated on the 309 & image of the crap accumulated on what would be the oil tank on the 309, hence the initial tank swap.

 

[captain dangers]

clutch removed from the 309 & worm drive fitted to the 309. 123 tank swapped over to the 309.

 

[captain dangers]

oil galleries required drilling out on the 309 crankcase, last image plugging the entry hole with JB weld.

 

[captain dangers]

oil pump, sprocket , brake band fitted to the 309 (still needs a tension spring, which I don't have at present)

 

[captain dangers]

exhaust, covers, felling dog fitted to the 309 , I could have put the top covers and air filter, exhaust off the 123 onto it , but I thought it may get a better air flow with the larger capacity filter, I am toying on the idea of advancing the timing a little in future ? have to see how it runs first? I was going to muffler mod it , but looking inside the muffler/exhaust of the 309 they not really that restrictive , so I left that alone. I decided to keep the exhaust guard though as it will help protect the exhaust as well as makes it look like a one-off/unique chainsaw ;o) the 123 clutch cover needs a little tweak to the plastic chain protector as they appears to be some slight difference in the crankcase around the brake band to get it to fit straight on. hope to get it out for a run tomorrow? I will have to try and find a bar/chain.

 

[captain dangers]

quick catch-up to show the 309 can now oil a bar after drilling out the oil galleries etc. just needs a few finishing touches and tune-up and she'll be good to go ;o)

 

[pioneerguy600]

What cylinder/piston are you using? I may have missed this but just curious.

 

[captain dangers]

What cylinder/piston are you using? I may have missed this but just curious.

I used the whole engine and crankcase out of a 309 and fit it into a tank off a 123 and used other bits of the 123 like oil pump , clutch etc. the crank was damaged in the original 123 crank cases hence the engine swap. I believe the 309 piston and cylinders are the same as a 123 (70cc) ? CD

 

[pioneerguy600]

I used the whole engine and crankcase out of a 309 and fit it into a tank off a 123 and used other bits of the 123 like oil pump , clutch etc. the crank was damaged in the original 123 crank cases hence the engine swap. I believe the 309 piston and cylinders are the same as a 123 (70cc) ? CD

I have yet to ever compare a set side by side but was always told that the demolition/concrete saws in general had a different intake and exhaust port timing numbers to prevent them from over revving. This may or may not be true, but would like to know for certain. Also have heard the demo saws ran a rev limited ignition but sort of doubted that after running a 309 ignition in my 133. More curiosity than anything else. would like to put one or the other to bed, right or wrong info.

 

[captain dangers]

I have yet to ever compare a set side by side but was always told that the demolition/concrete saws in general had a different intake and exhaust port timing numbers to prevent them from over revving. This may or may not be true, but would like to know for certain. Also have heard the demo saws ran a rev limited ignition but sort of doubted that after running a 309 ignition in my 133. More curiosity than anything else. would like to put one or the other to bed, right or wrong info.

we will have to wait and see, I know the carb has a what appears to be a no load governor (brass plug), but so does the 123 carb that I have, assuming its the original 123 carb?, I was always led to believe they limited the rpm on the 309 by fattening up the H mixture, the rpm was only lowered as a health/safety issue regarding the discs exploding ?

 

[pioneerguy600]

That may just be how they did it. I often hung around a Sachs Dolmar dealership and that was where I was told about the cylinder porting differences but actually never seen or handled a 309 cylinder and yes the needed to keep the rpm lower on the demo saws due to they reinforced blades coming apart at higher rpm. Let us know how the saw runs, maybe debunk some myths doing this.

 

[madhatte]

Neat project!

 

[wisme.jonat]

I finished up my conversion last year… the oil hole and plug were already completed on mine, made the job easier

 

[dakotacmw]

I have had this project to do for the last couple of years and ive been putting it off and finaly thought sod it! I'm going to have a go ;o) the project in hand was to convert an old sachs dolmar 309 to a chainsaw with some parts I had lying over from a 123 with a knackered crank. I anted the tank off the 123 putting onto the 309 as the 309 is full of debris/muck as, although dolmar used to blank the oil filler cap off on the 309 they left the oil pick-up aperture open which just allows dust etc. to get into the tank. other parts to transfer from the 123 were as follows: oil pump worm drive, oil pump, oil hoes etc, sprocket, bearing, clutch, chain brake mechanism. I had to drill out the oil galleries on the 309 crank case as dolmar obviously didn't bother doing these in the casting process on the disc cuter batches, presumably to save £ ?

photos 1-2 are the 309 and the 123 donor saws .

 

[dakotacmw]

I ended up doing this exact same thing to mine as well, I used to work as a mechanic in a shop where they were a Sachs Dolmar dealer in 1987. It was pretty easy back then because I had access to all the parts I needed. I still have the saw but now I want to convert it back to a cut off saw. The problem is, when I did the conversion back in the day I ended up “storing” all of the parts needed to convert it back. I figured I would keep them in case I ever needed to change it back, long story short, after several moves, a divorce and about 35 years later those parts are no where to be found. I’m wondering if you have any further need of the parts you removed from yours, if not, would you be interested in possibly selling those parts? If so, and we can come to some agreement as to price, maybe I can take those parts off of your hands, get them out of your way, and you get some extra cash in your pocket. Please let me know if this is something that you might be interested in. Happy cutting, stay safe!!

 

[captain dangers]

I ended up doing this exact same thing to mine as well, I used to work as a mechanic in a shop where they were a Sachs Dolmar dealer in 1987. It was pretty easy back then because I had access to all the parts I needed. I still have the saw but now I want to convert it back to a cut off saw. The problem is, when I did the conversion back in the day I ended up “storing” all of the parts needed to convert it back. I figured I would keep them in case I ever needed to change it back, long story short, after several moves, a divorce and about 35 years later those parts are no where to be found. I’m wondering if you have any further need of the parts you removed from yours, if not, would you be interested in possibly selling those parts? If so, and we can come to some agreement as to price, maybe I can take those parts off of your hands, get them out of your way, and you get some extra cash in your pocket. Please let me know if this is something that you might be interested in. Happy cutting, stay safe!!

i binned my parts bud. i'm in the u.k so it wouldn't be viable to posy anyway. you cheapest option by far is to look for a complete non-running dolmar 309 or makita dcs7000 (makita blue)and either fix it up or use as a donor saw. i believe the dolmar was also market as a wacker BTS 11 (painted yellow).


good luck with your project C D

 

[Papko]

I have had this project to do for the last couple of years and ive been putting it off and finaly thought sod it! I'm going to have a go ;o) the project in hand was to convert an old sachs dolmar 309 to a chainsaw with some parts I had lying over from a 123 with a knackered crank. I anted the tank off the 123 putting onto the 309 as the 309 is full of debris/muck as, although dolmar used to blank the oil filler cap off on the 309 they left the oil pick-up aperture open which just allows dust etc. to get into the tank. other parts to transfer from the 123 were as follows: oil pump worm drive, oil pump, oil hoes etc, sprocket, bearing, clutch, chain brake mechanism. I had to drill out the oil galleries on the 309 crank case as dolmar obviously didn't bother doing these in the casting process on the disc cuter batches, presumably to save £ ?

photos 1-2 are the 309 and the 123 donor saws .

 

[Papko]

Hi
You are right the Wacker BTS 11 was a Sachs Dolmar 309.
( and I think 343 in USA?)

The Yellow Wacker BTS11 were used a lot by MOD.
we are going back to 80s.
I have tonnes of parts for these.