Hi all,

Hopefully someone can point me in the right direction before its too late...

My NC 21 normally runs on lead replacement fuel, but due to sporadic unavailability I use unleaded fuel with 2 stroke oil from time to time. My question is : which fuel is better for my engine?

I find that when I use unleaded fuel with 2 stroke oil, the bike runs a lot smoother, but emits quite a lot of white smoke. Lead replacement fuel though, doesn't smoke as much, but seems to run quite rough, and tends to idle about 500 - 700 RPM higher than when on unleaded.

Any input is welcome

Stop putting in 2t and just run it on 95 RON unleaded.

karel84 wrote:Hi all,

Hopefully someone can point me in the right direction before its too late...

My NC 21 normally runs on lead replacement fuel, but due to sporadic unavailability I use unleaded fuel with 2 stroke oil from time to time. My question is : which fuel is better for my engine?

I find that when I use unleaded fuel with 2 stroke oil, the bike runs a lot smoother, but emits quite a lot of white smoke. Lead replacement fuel though, doesn't smoke as much, but seems to run quite rough, and tends to idle about 500 - 700 RPM higher than when on unleaded.

Any input is welcome

I wonder why 99% of the south africans on this board treat their bikes like they want to kill them. why the fuck would anyone put 2 stroke oil in fuel to compensate for some lead replacement fuel that you dont need in the first place.

its like putting salt in a cup of tea becuae there is no sugar... totally different stuff.

* leaded fuel provides valve seat protection via tetra ethyl lead.

* 2 stroke oil provides bearing lubrication. It will also lean your mixture out as you are burning less fuel and not compensating jettings, as well as carbon up all your engine and plugs a lot quicker.

this bike is designed to use normal unleaded fuel (as are all Japanese vehicles since the 1970s..) not LRP (which is just unleaded with valve seat additives so technically won't hurt but is NOT needed)

if putting oil in your bike is making it run better then your carb and jetting is probably messed up.

use normal unleaded and get the carbs sorted.

if your somewhere in high altitude you probably need to adjust your jetting anyway if it hasnt already been done.. 2t is probably doing this for you, while ruining your engine in the mean time (if its not ruined already)

How much oil are you putting in it to make it smoke that much?
If it's a lot then it will be running lean and a lean idle mixture will raise the rpm up.
Just use normal unleaded fuel and as Neo says, if it runs badly your carbs need sorting out.
Probably needs new plugs by now as well.

Neosophist wrote: if your somewhere in high altitude you probably need to adjust your jetting anyway if it hasnt already been done..

KZN is as low altitude as can go, right on the coast.

I thought Jap bike motors had been designed to run on unleaded fuel since the early 70's?

The real problem maybe finding petrol with the correct octane rating

Neosophist wrote:

karel84 wrote:Hi all,

Hopefully someone can point me in the right direction before its too late...

My NC 21 normally runs on lead replacement fuel, but due to sporadic unavailability I use unleaded fuel with 2 stroke oil from time to time. My question is : which fuel is better for my engine?

I find that when I use unleaded fuel with 2 stroke oil, the bike runs a lot smoother, but emits quite a lot of white smoke. Lead replacement fuel though, doesn't smoke as much, but seems to run quite rough, and tends to idle about 500 - 700 RPM higher than when on unleaded.

Any input is welcome

I wonder why 99% of the south africans on this board treat their bikes like they want to kill them. why the fuck would anyone put 2 stroke oil in fuel to compensate for some lead replacement fuel that you dont need in the first place.

its like putting salt in a cup of tea becuae there is no sugar... totally different stuff.

* leaded fuel provides valve seat protection via tetra ethyl lead.

* 2 stroke oil provides bearing lubrication. It will also lean your mixture out as you are burning less fuel and not compensating jettings, as well as carbon up all your engine and plugs a lot quicker.

this bike is designed to use normal unleaded fuel (as are all Japanese vehicles since the 1970s..) not LRP (which is just unleaded with valve seat additives so technically won't hurt but is NOT needed)

if putting oil in your bike is making it run better then your carb and jetting is probably messed up.

use normal unleaded and get the carbs sorted.

if your somewhere in high altitude you probably need to adjust your jetting anyway if it hasnt already been done.. 2t is probably doing this for you, while ruining your engine in the mean time (if its not ruined already)

91 or higher RON, thats about 85 MON for countries that use that and 88 if your in the US.

not many places have shittier gas than this anymore