Stay with my 125 or upgrade??
- Thread starter Kyle
- Start date
Sorry about being late to the party, but twenty sizes off? I'm really surprised that it even ran. That's something like a 2 to 1 difference in fuel.
Seems like you must of not had a manual. When working on a bike a manual is pretty much required unless you are only doing the most minor of stuff.
Now that you have the bike running correctly, I'd go with it for a while. You spent all that time and $$$ so enjoy it. It's not like you will be getting top dollar for an 125.
Seems like you must of not had a manual. When working on a bike a manual is pretty much required unless you are only doing the most minor of stuff.
Now that you have the bike running correctly, I'd go with it for a while. You spent all that time and $$$ so enjoy it. It's not like you will be getting top dollar for an 125.
Well Kyle... I think the YZ125 is an awesome bike but your lack of basic knowledge for owning a "race" bike has prevented you from getting the most out of it and buying a 250f will only compound this problem. Yeah you may have enough money to get a washing machine to fly but how long can you afford to keep flying it?
Lets start with the basics:
Jetting... A 2T race bike needs to be jetted properly on a regular basis. I will sometimes jet mine 2-3 times a day based on temps etc etc.... but the following things will also effect your jetting. Fuel and its quality... No 2 pump fuels are the same and Race Gas is WAY different. Riding style.... A really Fast MXer will need a richer running bike than say someone that likes tight single track. Type of Premix oil.... Did you know that different premix oils come in different viscosities? They do, so everytime you switch oils you may be changing your bikes jetting. Mix Ratio... That can greatly effect your jetting as well... A clean Carb and a clean bike... dirty or clogged vents can cause poorly running bike and dirt in the carb can easily lean out a jet... Also the amount of accumulated lacquer in your carb can lean out your jetting as well...... So get used to jetting a bike... Great thread on TT about jetting and I think it may even be here on DBA.
Lets talk oil..... I currently ride/race an RM250.... my Factory specs say I should run 30:1 premix ratio of a premium "racing" oil. My premium racing oil says it mixes well at 40:1..... It also says to follow my engine manufacturers recommended ratio... I always have mixed 30:1 in that bike and NO issues... My son used to ride a RM85, but I mixed his oil at 24:1, why? because that little monster needed oil! I mixed rich and jetted for it... Same goes for a 125, If its revving to the moon feed it oil but remember to adjust the jetting... remember this " Oil rich, fatten that jet"
Good luck...
Lets start with the basics:
Jetting... A 2T race bike needs to be jetted properly on a regular basis. I will sometimes jet mine 2-3 times a day based on temps etc etc.... but the following things will also effect your jetting. Fuel and its quality... No 2 pump fuels are the same and Race Gas is WAY different. Riding style.... A really Fast MXer will need a richer running bike than say someone that likes tight single track. Type of Premix oil.... Did you know that different premix oils come in different viscosities? They do, so everytime you switch oils you may be changing your bikes jetting. Mix Ratio... That can greatly effect your jetting as well... A clean Carb and a clean bike... dirty or clogged vents can cause poorly running bike and dirt in the carb can easily lean out a jet... Also the amount of accumulated lacquer in your carb can lean out your jetting as well...... So get used to jetting a bike... Great thread on TT about jetting and I think it may even be here on DBA.
Lets talk oil..... I currently ride/race an RM250.... my Factory specs say I should run 30:1 premix ratio of a premium "racing" oil. My premium racing oil says it mixes well at 40:1..... It also says to follow my engine manufacturers recommended ratio... I always have mixed 30:1 in that bike and NO issues... My son used to ride a RM85, but I mixed his oil at 24:1, why? because that little monster needed oil! I mixed rich and jetted for it... Same goes for a 125, If its revving to the moon feed it oil but remember to adjust the jetting... remember this " Oil rich, fatten that jet"
Good luck...
End of thread right here^^^^^^ I always mixed at 32:1 and our bikes ran flawless. One of my good buddy's always thought that he should lean out his mix ratio and his bikes blew up constantly. Coincidence? I think not. Thank Mike for this informative and ensightful post despite the fact that it wasn't entertaining.
James
Staff member
Kyle read these.
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/#post-44613
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/page-2#post-44746
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/#post-44613
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/page-2#post-44746
Did you just call my bike a washing machine?
Outstanding, informative, helpful and somewhat enlightening post.........I give this twoKyle read these.
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/#post-44613
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/page-2#post-44746
Did you just call my bike a washing machine?
Kyle read these.
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/#post-44613
https://www.dirtbikeaddicts.com/threads/04-yz125-gas-and-oil-mixture.2240/page-2#post-44746
Did you just call my bike a washing machine?
Nope...
Your wallet is tighter than a frogs ass and thats water tight so you do the proper maintenance and go above and beyond to make sure that your "race" bike doesnt cost you more than it has too... you learn asmuch as you can so it saves you both time and squish in the longrun...
as for Nedge's comment
ouche: Thats French Canadian...Well, thanks... I pretty much just know how to change the oil and clean my carb. If I keep this bike (which all of you are suggesting I do) I want to learn how to do top ends. My yamaha instruction Manuel is complete sh*t. James can testify to that lol. But, I really don't want to screw this up so I am going to take it to another shop where I trusted them all along and the mechanic is known for being extremely good with carbs. So I will give him a holler. But, I don't think I will take separate jets to the track and ride then tear it apart to try a different jet. I want to just ride. As long as it will run healthy then I don't really care about getting a tiny bit more of power because guess what?? My bike is already slow as he'll sence it is a 125
haha thanks man.
haha a well tuned 125 is not slow as hell. i saw a video of what think was a privateer, jumping laroccos leap on a stock yz 125. if your bike can make laroccos leap than it simply is not slow as hell lol. if you dont like your yamaha manual get a chiltons. if you dont like the chiltons then you are S.O.L. good luck dude
Again, crate it up and ship it to me if it is that slow....Well, thanks... I pretty much just know how to change the oil and clean my carb. If I keep this bike (which all of you are suggesting I do) I want to learn how to do top ends. My yamaha instruction Manuel is complete sh*t. James can testify to that lol. But, I really don't want to screw this up so I am going to take it to another shop where I trusted them all along and the mechanic is known for being extremely good with carbs. So I will give him a holler. But, I don't think I will take separate jets to the track and ride then tear it apart to try a different jet. I want to just ride. As long as it will run healthy then I don't really care about getting a tiny bit more of power because guess what?? My bike is already slow as he'll sence it is a 125
Well, thanks... I pretty much just know how to change the oil and clean my carb. If I keep this bike (which all of you are suggesting I do) I want to learn how to do top ends. My yamaha instruction Manuel is complete sh*t. James can testify to that lol. But, I really don't want to screw this up so I am going to take it to another shop where I trusted them all along and the mechanic is known for being extremely good with carbs. So I will give him a holler. But, I don't think I will take separate jets to the track and ride then tear it apart to try a different jet. I want to just ride. As long as it will run healthy then I don't really care about getting a tiny bit more of power because guess what?? My bike is already slow as he'll sence it is a 125
a 125 is fast as hell!
Maybe you aren't understanding me....... learn to jet.... Proper jetting doen't just help with performance it helps to properly lubricate the engine.... You may not feel the need to do it everyday like me but you will need to do it from month to month.... Even 4Ts need to be jetted from season to season and even some of the FI ones you have to change the nozzles I believe....
Jetting is easy as pie and once you learn to do it and know how the bike should run then it will take you more time to lube the chain than it will to change your jets. trust me on this...
How though? You have to pull the carb out lol. Like I guess that only takes three minutes but I see two things wrong.
1: the dust from the track could get in my carb while im at the track.
2: it would just et annoying! But, you guys are right; I really so need to learn how to make my own carb adjustments. But, how do I learn without ruining my bike?
Also, is jetting going to be he same for a different two stroke... Like a kx125 or a cr250? Could I get references from those guys. Now I know they will be a few sizes off because I will have different upgrades. But, will it be in the same "ball park"?
James
Staff member
Can't you just rotate it? Here's how my 05 was.
https://www.dirtbikeaddicts.com/threads/removing-the-float-bowl-from-a-2005-kx250f-rmz250.4205/
just loosen both boots on the each side of the carb and rotate the bottom towards you. Four screws pops off the bowl then you have access to both the main and the pilot. 5 mintues you can change them out and be back on the track. I know you are not riding every second that you are at the track. While you are sitting around BS'n about how fast you are, change them out.