Author Topic: Am I running too lean??  (Read 1200 times)

0 Members and 1 Guest are viewing this topic.

Offline JaredRM250

  • Junior
  • **
  • Posts: 56
    • View Profile
Am I running too lean??
« on: April 25, 2013, 03:26:43 AM »
I have been riding my bike at 40:1 for about 12 hours (thats the use since I got it) the dealer told me to mix at 40:1 but today when I recieved the service manual it says I should run 30:1. I'm a little worried because I don,t want to risk seizure.

Any info would be great
cheers,
Jared.

Offline eprovenzano

  • Professional
  • *****
  • Posts: 1647
    • View Profile
Re: Am I running too lean??
« Reply #1 on: April 25, 2013, 04:17:06 AM »
A mixture at 40:1 is (IMO) right where you want to be.  With today's oils I've seen people running up to 100:1.  Now for me, I've jetted by bike to run at 45:1.  Can I ask what oil you are running?
Eric Provenzano
2001 KTM 380 EXC (mine)
2000 KTM 300 EXC (son's)
2006 KTM 250SXF SOLD!!!
1999 Honda 400 EX traded for a 2006 KTM 250 SXF
Sold 1999 KX250
Sold 1999 YZ125 (son's)
Sold 2001 Yamaha TTL 125 (son's 1st bike)
Sold but never forgotten 1974 Honda Elsinore CR250M
Sold 1974 Honda Elsinore CR12

Offline beaner

  • Professional
  • *****
  • Posts: 641
    • View Profile
Re: Am I running too lean??
« Reply #2 on: April 25, 2013, 04:32:37 AM »
Without knowing what the bike is, and what you're doing with it, it's not possible to say.

Trail riding a KDX 220? You're fine.

Racing a 85? You're not.

Ontario, Canada

Offline JaredRM250

  • Junior
  • **
  • Posts: 56
    • View Profile
Re: Am I running too lean??
« Reply #3 on: April 25, 2013, 05:09:15 AM »
A mixture at 40:1 is (IMO) right where you want to be.  With today's oils I've seen people running up to 100:1.  Now for me, I've jetted by bike to run at 45:1.  Can I ask what oil you are running?

The dealer recommended putoline offroad 2t
Cheers for feedback mate.

Offline chump6784

  • Professional
  • *****
  • Posts: 373
    • View Profile
Re: Am I running too lean??
« Reply #4 on: April 25, 2013, 07:01:24 AM »
I ran silken at 40:1 in my 07 rm 250 for over 2 years with no problem. The manual always leans to the side of caution, except for ktm who recommend 60:1 on the 250 sx, I'm running 50:1 on it though

Offline SwapperMX

  • Professional
  • *****
  • Posts: 689
    • View Profile
Re: Am I running too lean??
« Reply #5 on: April 25, 2013, 07:50:42 AM »
Without knowing what the bike is, and what you're doing with it, it's not possible to say.

Trail riding a KDX 220? You're fine.

Racing a 85? You're not.

His name was a giveaway !!  ;D

Offline Jeram

  • Professional
  • *****
  • Posts: 783
    • View Profile
Re: Am I running too lean??
« Reply #6 on: April 25, 2013, 08:38:14 AM »
why bother with running less oil in the fuel?

more = more protection
AND
more oil = better ring seal = more power

the only downside is that more oil = more smoke!

Offline cnrcpla

  • Professional
  • *****
  • Posts: 2184
    • View Profile
Re: Am I running too lean??
« Reply #7 on: April 25, 2013, 09:27:32 AM »
Quote
the only downside is that more oil = more smoke!
That's not a down side, its called mosquito repellant  ;D If it was running lean, the plug would have a white covering on it.
Mixin' gas and kickin' ass, Burnin' oil and smellin' royal. Two stroke until I die (which hopefully isn't soon)   If your not mixing gas, your not kicking ass.

Offline beaner

  • Professional
  • *****
  • Posts: 641
    • View Profile
Re: Am I running too lean??
« Reply #8 on: April 25, 2013, 09:39:43 AM »

His name was a giveaway !!  ;D

Mine is Beaner and I'm not Mexican  ;D
Ontario, Canada

Offline Jeram

  • Professional
  • *****
  • Posts: 783
    • View Profile
Re: Am I running too lean??
« Reply #9 on: April 25, 2013, 10:31:34 AM »
haha beaner...

to the OP: be carefull with the terminology as you've said Lean in the title which generally refers to the fuel/air ratio not the fuel/oil ratio.

Playing with oil ratios will have a very small effect on the fuel/air ratios, but nothing to be really concerned about.

But I assume your simply asking about whether your motor has sufficient protection with 40:1 vs 30:1.


PS: I run 20:1 in most of my bikes without any issues at all !!!!
But thats for modified motors.

Offline vetman

  • Expert
  • ****
  • Posts: 162
    • View Profile
Re: Am I running too lean??
« Reply #10 on: April 25, 2013, 12:56:51 PM »
Ive run 40:1-45:1 on every 2 stroke ive owned never had a issue so long as you run good quality oil,everyone has there favourites me,im running belray H1R but plenty of good options out there.

Offline SwapperMX

  • Professional
  • *****
  • Posts: 689
    • View Profile
Re: Am I running too lean??
« Reply #11 on: April 25, 2013, 01:02:31 PM »

His name was a giveaway !!  ;D

Mine is Beaner and I'm not Mexican  ;D

I'm sure it's funny, but I dont get it. Please explain ??

Offline evo550

  • Professional
  • *****
  • Posts: 854
    • View Profile
Re: Am I running too lean??
« Reply #12 on: April 25, 2013, 01:06:36 PM »
This is a real good thread albeit llllloooooonnnngggg, but tries to dispel a lot of 2t oil myths.
http://ozvmx.com/community/index.php?topic=8661.90

To try and make a long story short, basically different 2t oils have different viscosities (Thicknesses..sort of) so one oil mixed at 20:1 vs another mixed at 50:1 may well equal the same %'s of fuel to oil in the gas tank.
Most motorcycle manufacturers....or the good ones anyway, will specify a mixture ratio with a specific oil.
Ktm do specify 65:1 using Motorex 2t oil
My '84 Maico specified 100:1 using Maico Mc 100 oil?
« Last Edit: April 25, 2013, 01:11:47 PM by evo550 »

Offline 2T Institute

  • Professional
  • *****
  • Posts: 712
    • View Profile
Re: Am I running too lean??
« Reply #13 on: April 25, 2013, 01:56:16 PM »
The part where old mates thesis comes unglued is it won't have any effect when you dilute the oil with fuel. Testing the oil viscosity itself is meaningless. I fuel/air molecule will take 20 revolutions to go through the engine what happens in 20 revs not many know.
I have been riding my bike at 40:1 for about 12 hours (thats the use since I got it) the dealer told me to mix at 40:1 but today when I recieved the service manual it says I should run 30:1. I'm a little worried because I don,t want to risk seizure.


You will seize with lean jetting before lack of oil. 

Offline JaredRM250

  • Junior
  • **
  • Posts: 56
    • View Profile
Re: Am I running too lean??
« Reply #14 on: April 25, 2013, 02:35:12 PM »
Without knowing what the bike is, and what you're doing with it, it's not possible to say.

Trail riding a KDX 220? You're fine.

Racing a 85? You're not.

2008 RM250 and the riding style is 85% motocross/enduro and 15% trail riding because of the lack of places to ride in the UK.