Gas oil mix for 83 Yz 490
- Thread starter Slipperypickerl
- Start date
I've run 32:1 all the way up to 80:1, usually keep it between 40 and 50:1 on all my bikes. Have never had a catastrophic failure because of this, and see normal wear after normal rebuild intervals. The key is to use a good quality 2t oil, preferably synthetic. Now I also spend most of my time on the trail, don't keep the bikes on the redline all day so if you ride track or wide open areas , I'd probably keep it at 32:1.
I am still on 20-1 mixes. A big one that is actually held wide open ends up blowing it out really fast due to volume. if you are like most people you will enjoy not having to shift down very much and will delight yourself by rolling on the throttle in 3 gear around corners at walking speed and rolling the throttle on and repeating just to show you can. In other words, lugging to the extreme. Life can be tough on a big two stroke. So I still use 20-1 mixes. Especially on my big ones, because I know I am going to lug them, and I know when I get on a long stretch of straight stuff it will be wound up to where the pipe and carburetor work to keep it from reving any further.
The WR500 has seen neary 400 hours with a 32:1 walmart marine oil mix. Not one deposit or abnormal wear marks. I completely lug it some rides, and other rides I hold her to the stop.
Check out my build threads to see the internals yourself. Hundreds of photos.
Honestly if you do the actual math, changing from 20:1 to 40:1 (2.5%) is less than one jet change (3.8%)in the carburetor. So ultimately the oil/fuel mixture conversation is totally dead in my mind. Air/fuel mix on the other hand...
-BIG DAN
Check out my build threads to see the internals yourself. Hundreds of photos.
Honestly if you do the actual math, changing from 20:1 to 40:1 (2.5%) is less than one jet change (3.8%)in the carburetor. So ultimately the oil/fuel mixture conversation is totally dead in my mind. Air/fuel mix on the other hand...
-BIG DAN
I was surprised also, but the manual stated run in at 40-1 then continue with 60:1. When I pulled mine down for the first time this year after 3 seasons, I saw zero sign of oil starvation. I wonder if case reeds allow for the same lubrication with a leaner mixture as cylinder induction with a richer mix....no idea just a thought.
The WR500 has seen neary 400 hours with a 32:1 walmart marine oil mix. Not one deposit or abnormal wear marks. I completely lug it some rides, and other rides I hold her to the stop.
Check out my build threads to see the internals yourself. Hundreds of photos.
Honestly if you do the actual math, changing from 20:1 to 40:1 (2.5%) is less than one jet change (3.8%)in the carburetor. So ultimately the oil/fuel mixture conversation is totally dead in my mind. Air/fuel mix on the other hand...
-BIG DAN
I don't do math....but I believe in it.
The WR500 has seen neary 400 hours with a 32:1 walmart marine oil mix. Not one deposit or abnormal wear marks. I completely lug it some rides, and other rides I hold her to the stop.
Check out my build threads to see the internals yourself. Hundreds of photos.
Honestly if you do the actual math, changing from 20:1 to 40:1 (2.5%) is less than one jet change (3.8%)in the carburetor. So ultimately the oil/fuel mixture conversation is totally dead in my mind. Air/fuel mix on the other hand...
-BIG DAN
A lot of it has to do with engine tolerances. When they design and build the motor and then use the fuel oil to compensate. New ktm, leaner mixtures.
A big old school air cooled motor will chug down the fat mix but there is a difference between racing a motor and running a motor.
thanx for all the help guys gonna try 32:1 see how that goes