Hi , and to get away for the virus talk......
My friend has a 3 cylinder / 2 stroke motor in his DKW ,
it is not driven very much , but when he does drive it he fumigates the neighborhood.
So does the smokeless oil really work ? Is one brand better than another ?
And also will one of those small Japanese K car superchargers work on a 2 stroke ?
Thanks for your ideas......
Also if you have any interesting 2 stroke / 3 cylinder motors running , DKW , Saab or Snowmobile etc please show some pictures.....
My F500 (rotax 494 snowmobile motor) smokes on first startup after sitting for awhile. Generally stops smoking (well, relatively at least) after the first autocross run.
First run only.
later runs good.
The general F500 braintrust tells me that its likely a slow leak of my injection pump and normal and not necessary to fix.
Yes you can supercharge a 2 stroke. DKW did it themselves on a motorcycle before WW2. We ran Klotz synthetic in 2 stroke Polaris triples for TQ midget racing in the distant past. It was very much better than conventional or castor oil. We even ran them indoors at Niagara Falls Convention Center. Photo is last lap of feature with about 1/2 of cars running 2 strokes, including the winner.
The DKW is likely sporting iron liners, which smoke like made on start up. My F500 use a motor (AMW) with iron liners, on start up it will leave a huge cloud bu once warmed up barley smokes at all. For oil I use Yamalube 2R.
supercharging two strokes has been done many times but you can also get huge benefits from expansion chamber. Given the DKW isn't sporting any sort of expansion chambers I might go there first.
Tom1200 said:
The DKW is likely sporting iron liners, which smoke like made on start up. My F500 use a motor (AMW) with iron liners, on start up it will leave a huge cloud bu once warmed up barley smokes at all. For oil I use Yamalube 2R.
supercharging two strokes has been done many times but you can also get huge benefits from expansion chamber. Given the DKW isn't sporting any sort of expansion chambers I might go there first.
Well its a "street" DKW so are there expansion chamber exhausts that do not wake the dead :)
When I had my SAAB 96 with oil injection I always used their oil .
I tried Mobil 2 cycle. Wife asked me what was wrong.
AMSOIL makes a good 2 cycle oil.
Any 2 stroke is going to smoke when it's cold unless the oil is cut way back, but then it won't have sufficient lubrication. Modern 2 stroke oils are very good and he should be running a low flash point oil which, if it's oil injected, he's probably already running. If it's premix and he's running a high flash point oil, that's not helping. The DKW is probably a low performance low compression 2 stoke so it's going to smoke pretty good when cold anyway. If it does when warm then it's likely either an (if it even has) oil injection problem , low compression, or very rich jetting.
Amsoil Interceptor is an excellent oil, and Yamalube 2R is a very good budget choice, but there are a lot of quality oils available these days, just don't use a high flash point oil in a low performance application or it will either smoke or spooge like crazy
I used smokeless oil in my dirt bike. Not truly smokeless but much better. The real benefit was that I got probably triple the life out of a spark plug and my muffler packing didn't drip black goop anymore.
Thanks for the info ,
this is an early 50s model and I am sure the fuel available was low octane ,
I wonder if the oil settles on the bores when its stored and once started burns off and smokes,
I will have to ask if its premix or not , but he is in 3 weeks SF Bay lockdown now !
Stay Safe
The Audi 1000 (upgrade DKW) had a belt driven oil injector pump.
The DKW was premixed.
If my old memory serves me right.
Before Audi it was Auto Union
I run motorex synthetic in my bikes of all ages with great success and really good piston and plug life, including old air cooled stuff.
Every 2 stroke I have had has smoked when cold on the first start of the day. I have a (completely unverified) theory that fuel and oil pool in the crankcase when the engine has been sitting, and the gas evaporates out of it. On the first cold start after sitting, it picks up that slug of oil, but the combustion chamber isn't hot enough to burn it properly, and then it sits in the pipe and "smokes off" as it heats up since there isn't enough heat/pressure/entrained fuel to actually combust it.
