2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: rd400canuck on March 09, 2020, 01:57:52 PM

Title: loads of smoke?
Post by: rd400canuck on March 09, 2020, 01:57:52 PM
Just curious... is it normal for an RD400 to smoke like a chimney with premix at 32:1 ?

I have a 27.5 in there right now instead of the stock 25 pilot so maybe that's why?

Thank you,

John
Title: Re: loads of smoke?
Post by: Greaser Greg on March 09, 2020, 02:08:01 PM
No idea., but: When first running my R5 it  smoked a lot because I had kicked it a bunch before it fired and burned off the built-up unburned fuel. How long did you run it? Asfaik the requirement for oil at idle is pretty low, goes up with revs. That's why the pumps are desireable for idle speeds, ratio is something around 100:1. :twocents:
Title: Re: loads of smoke?
Post by: SUPERTUNE on March 09, 2020, 10:30:04 PM
Why 32:1?
Way to much for a streetbike on modern oils.
No more than 40:1 in cold climates and 50:1 in higher climates like the south using high end ester based oils if not a track bike.

Chuck
Title: Re: loads of smoke?
Post by: 1976RD400C on March 10, 2020, 08:00:36 AM
Not sure how much you have run it but it is going to belch out smoke the first time you run it up through the gears after starting it. Once the lower end blows clean it should get better.
Title: Re: loads of smoke?
Post by: m in sc on March 10, 2020, 10:00:20 AM
agreed. chuck politely gave me the same speech via msg a few weeks ago. of course, hes right. 40:1 = good. 32:1 is ok as well, but it will smoke more. (ive never had an issue).  But, that initial run will always bench out a cloud.

just make sure its not smoking -notably- MORE out of the RH pipe as that can be a sign of a bad crank seal.
Title: Re: loads of smoke?
Post by: rd400canuck on March 10, 2020, 02:16:32 PM
ok, thanks guys... I'll go to 40:1 since this bike isnt going to have the crap ring out of it; until I got the pump rebuilt and tested.

Title: Re: loads of smoke?
Post by: paul1478 on March 10, 2020, 02:34:08 PM
I use 40:1 and my bike sees over 10K. When we took it apart piston and bore looked new.