quick jetting question
- Thread starter kdxracer577
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pyromaniac
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- Jun 25, 2000
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Why would you want to run leaner premix? I would say the more oil the better. Ofcourse there are limits. I run 3 to 4% oil and i would never go under 3%. The more oil the less risk for seize and the longer your piston last.
Some people say i run too much oil. Oh yeah why i say. Have i ever had any problem? No. Is my bike slower than theirs? Well im not slower on the track. Have i ever seized a bike? No. Have they? Yes.
Unless you have problem running 3% i would not run less. The only reason I can see other than having problem is that is the oil cost but i think you will save that money since the piston lasts longer.
Performance gain, dont think so! If you have it jetted right for the amount of oil you have you should feel no difference in performance wether you are running 2 or 5% oil.
Some people say i run too much oil. Oh yeah why i say. Have i ever had any problem? No. Is my bike slower than theirs? Well im not slower on the track. Have i ever seized a bike? No. Have they? Yes.
Unless you have problem running 3% i would not run less. The only reason I can see other than having problem is that is the oil cost but i think you will save that money since the piston lasts longer.
Performance gain, dont think so! If you have it jetted right for the amount of oil you have you should feel no difference in performance wether you are running 2 or 5% oil.
Faded
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- Jan 7, 2003
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From my experience those with absolutely ZERO jetting experience ( most of the people I ride with, and up until lately myself included ) have, at one time or another, had problems with spooge, oil build-up and rich running bikes that were jetted rich from the begining. Most people see this as the premix ratio that causes the spooge, fouled plugs, and gooey mess on the exhaust valves. Instead of questioning the jetting one ass-umes that there is too much oil because that is what is seen all over the bike.
By lowering the oil content of the premix the bike will have an easier time burning the gas which equates into fouling fewer plugs, making more power (have you ever tried to light oil on fire? It takes awhile, but gas...BABOOM!) and not having so much oily byproduct making a mess all over the bike. :confused:
Of course we all upin' Idahoe know this is true which is why all the CR500 equiped pipe-movers run 50:1, 60:1, and even 80:1 with 85 octane pump gas and Homelite, or any other generic brand 2 stroke weed wacker oil package in a black quart-sized bottle.
I consider myself lucky. A tiny voice in my head warned me to ignore the advice of those around. I did, and chose Amsoil at 40:1. Not bad, but now I have the power of knowledge on my side. This spring I'll be spending some quality time with my bike, a box full of jets, and some 32:1 to 24:1 with those first numbers hopefully being race gas (if I can find some locally).
By lowering the oil content of the premix the bike will have an easier time burning the gas which equates into fouling fewer plugs, making more power (have you ever tried to light oil on fire? It takes awhile, but gas...BABOOM!) and not having so much oily byproduct making a mess all over the bike. :confused:
Of course we all upin' Idahoe know this is true which is why all the CR500 equiped pipe-movers run 50:1, 60:1, and even 80:1 with 85 octane pump gas and Homelite, or any other generic brand 2 stroke weed wacker oil package in a black quart-sized bottle.
I consider myself lucky. A tiny voice in my head warned me to ignore the advice of those around. I did, and chose Amsoil at 40:1. Not bad, but now I have the power of knowledge on my side. This spring I'll be spending some quality time with my bike, a box full of jets, and some 32:1 to 24:1 with those first numbers hopefully being race gas (if I can find some locally).
alright ive read every single post and im still lost! I went riding today and a buddy said that he was able to follow me by my smoke!! I run 32:1 with Klotz/ pump gas, I ride woods and dident foul a plug all day, amazed! but my bike does smoke and has a trail of spooge running down my silencer, what do i need to do to get rid of it?? OR is it just because i run pump gas??
yeah, I think we strayed a little away from your original question, it happens sometimes. You need to go to the JustKDX site and read the article on jetting. There's a link to it in one of the first 5 posts in this thread. This will tell you what to do, how to do it, even give you some recommendations to start from. But, it's your jetting that is causing the smoking and spooge you're complaining of --- unless it is a mechanical problem; ie. blown crank seal, waterpump seal, over oiled filter, etc.etc. I think that website goes into that also as an "underlying" problem.
Anyway, read the article, try some jetting changes, then get back with us, tell us what you found, and we'll get you sorted out!
Anyway, read the article, try some jetting changes, then get back with us, tell us what you found, and we'll get you sorted out!
jmics19067
LIFETIME SPONSOR
- Jan 22, 2002
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As Rich Rohrich stated earlier it is a combination of factors. Jetting, engine condition and the type of fuel /oil mixture.
Jetting is obvious in that you want the right amount of air with the right amount of fuel to get a good clean efficient burn. Probably the most blatant problem in most bikes.<mine included>
Engine condition and type of fuel gets a lot more complicated . I understand the idea but have no clue on intricacies of how and why. You need the right amount of heat, vacuum signal, and velocity in the intake to vaporize the proper distillate rate of the fuel. Probably hundreds of other variables to line up correctly to get the "perfect "burn.
If you are using pump gas in a stock motocross bike cruising around in the woods at a low rpm. I can understand how pump gas <with a high distallate tempature> is not getting completely atomized and burned efficiently in an engine that is not really being run to the peak of its design. I couldn't tell you why though.
If you were to run a fuel like VP's C12 and the carburator jetted crisp you would eliminate a lot of the problem. I know this from the 5 days a year that the jets in my carb actually match up to the conditions I am in:)
Jetting is obvious in that you want the right amount of air with the right amount of fuel to get a good clean efficient burn. Probably the most blatant problem in most bikes.<mine included>
Engine condition and type of fuel gets a lot more complicated . I understand the idea but have no clue on intricacies of how and why. You need the right amount of heat, vacuum signal, and velocity in the intake to vaporize the proper distillate rate of the fuel. Probably hundreds of other variables to line up correctly to get the "perfect "burn.
If you are using pump gas in a stock motocross bike cruising around in the woods at a low rpm. I can understand how pump gas <with a high distallate tempature> is not getting completely atomized and burned efficiently in an engine that is not really being run to the peak of its design. I couldn't tell you why though.
If you were to run a fuel like VP's C12 and the carburator jetted crisp you would eliminate a lot of the problem. I know this from the 5 days a year that the jets in my carb actually match up to the conditions I am in:)
