Help this newbie !!

[mi-bowhunter]

I recently aquired 99 yz125, I am a new rider so im not balls to the walls as of yet, the problem im having is I keep fouling plugs after 30 min of riding, when I pull them the are black and smell real rich, I spoke to the previous owner and he said the carb is all factory settings, he suggested to go to a hotter plug.

My knowledge is very little so far so I ask you guys and gals what plug should I run to help extend the life of em ??

Is there any adverse affects to running a hotter plug ??

Should I switch back to the factory reccomended plug when I become a better ridder?

Any and all help is greatly appreciated.

Thanks :ride:

 

[BigSwole]

Your jetting is off. Change the pilot and main. What are you running for mixture? What's your elevation? What's the weather like?






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www.2strokesrus.com

 

[mi-bowhunter]

Im running 32-1(factory mix) Which if I am correct on my mixing thats 4oz's oil to 1 gallon gas ??
I currently am using bel-ray H1R

I am located in Michigan, its sunny and 60's

 

[DLHamblin]

I recently aquired 99 yz125, I am a new rider so im not balls to the walls as of yet, the problem im having is I keep fouling plugs after 30 min of riding, when I pull them the are black and smell real rich, I spoke to the previous owner and he said the carb is all factory settings, he suggested to go to a hotter plug.

My knowledge is very little so far so I ask you guys and gals what plug should I run to help extend the life of em ??

Is there any adverse affects to running a hotter plug ??

Should I switch back to the factory reccomended plug when I become a better ridder?

Any and all help is greatly appreciated.

Thanks :ride:

The std heat range plug on a 125 is assuming you are running it hard. Assuming your jetting is close; if you are not running the motor hard you can go 1 heat range hotter without any worry. Many people do this when trail riding them etc.

Make sure you check whats in it and what is supposed to be in it from the manual first

 

[sandflyz]

Jet it properly before you begin to change sparkplug heat ranges. If the jetting is stock and you are anywhere above sea level you will be to rich. You can learn how to properly jet your bike here just do a search for jetting. This will make more difference than anything else you do to your bike.

 

[FruDaddy]

There are several good jetting links in the stickies at the top of this forum that should help get your carb right. Stock settings are just a baseline. The hotter plug may help, but it just a band aid. As for the oil ratio, 4oz per gallon is 32:1. If you invest a couple bucks into a ratio rite it will simplify your life.

 

[Wytboi]

I had the same problem when I first got my '02 YZ250. The bike is fine- twist the throttle! I fouled 2 plugs the first time I rode mine. Keep riding, you will be surprised at how fast you will get used to the bike. Before long you will have it pegged wide open most of the time and fouled plugs will go bye-bye. I haven't fouled a plug since that first day. Good luck!

By the way, I run stock jetting and a richer 40:1 mix. :laugh:

 

[mi-bowhunter]

Well I changed to a BR8 plug and everything seems good, Thanks to everyone for your help and comments

 

[snb73]

mi-bowhunter,

Start from scratch with the recommended plug and stock jetting, then rejet from there.


Here is a jetting baseline:

http://www.mx-stuff.com/jettingspecs.htm


NGK specifies a BR9EG or a BR9EIX for your bike.

http://www.ngksparkplugs.com/apps/motorcycles/make4.asp?id=2951&type=reg

http://www.ngksparkplugs.com/apps/motorcycles/make4.asp?id=2951&type=ir


Using a "BR8" plug, you are using the wrong plug and could cause engine damage by using a too "hot" plug. As said before, don't change your plug to correct a rich condition, you must rejet your bike!


These articles will help you to properly jet your bike:

http://ericgorr.com/techarticles/carbtuning.html

http://ericgorr.com/techarticles/sparkplugs.html


Hope this helps, Steve.

 

[NacNac250F]

I run stock jetting and a richer 40:1 mix. :laugh:

40:1 is a leaner mix, or less oil in the gas.

40:1 = 3.2oz oil to a gallon of gas

32:1 = 4oz oil to a gallon of gas

 

[Wytboi]

40:1 is a leaner mix, or less oil in the gas.

40:1 = 3.2oz oil to a gallon of gas

32:1 = 4oz oil to a gallon of gas

Wrong! Not going to bother to explain. :bang:

 

[NacNac250F]

explain please, i wanna hear how less oil is richer!

 

[sunnyboy]

BOY!!!!!!!!!1 lots of good advice--- yes go back to the factory recomended plug-----check your jets they should be factory--pull the needle and raise the clip one notch,that should clear up your problem--some times the easy ones get missed

 

[MotocrossMike]

Help

get a hotter spark plug which means it is longer. it worked for me

 

[FruDaddy]

explain please, i wanna hear how less oil is richer!

Less oil=more gas
More gas=richer mixture
Need more detail?

 

[Lokair]

Ok , One or even two steps hotter on your plug will in no way hurt your bike, Unless you are running way lean already. I run a rich mixture of 50:1 in my YZ250 and I use a plug that is one or two steps hotter(I change them due to weather and where I am going ridding) at the moment, Ran it like that and the old piston is in like new condition with 56 hours on it to boot(i just did a rebuild with a new piston and ring). Now if you want the bike to run even better you should jet it to the stock plug and to the conditions it will be ridden(ie humidity, temperature and riding style, woods track, enduro, ect.)

Now once you have it tuned in to say track riding(wide open alot and such) and you are gonna go to the woods for some action you may wanna just put in a hotter plug due to the nature of woods riding then make sure to clean out the bike every now and then with a wide open blast.

The way rich and lean works in referance to Gas and Air (no where does it mention oil for two strokes or any thing else) so if you run 32:1 (wich Yamaha say to run 30:1 for all you technical geeks out there). rich means more Gas and less air , so if you mix more oil in you are leaning out your bike by taking gasoline out of the mix and replacing that part with oil.

32:1 = 32 parts Gas and 1 part oil
50:1 = 50 Parts Gas and 1 part oil
see more gas in the 50:1 than the 32:1 wich would make the 50:1 richer

 

[chevy383cid]

Read all and every jetting link on 2 strokes that you can find, ,-buy a JD jetting kit and two new plugs---- Install the JD kit-- warm up bike GOOD---Install new plug and do a plug chop--pull plug and read it and go from there!! JD kits are about 59.00 and are TOP OF THE LINE, They come with two special tapperd needles, one pilot and three mains and instructions on how and wich needle,jets to install for your elevation. Trust me, it's money well spent!!

 

[NacNac250F]

Less oil=more gas
More gas=richer mixture
Need more detail?

OK fair enough. But in a 125 I like to run more oil in the gas to be safe because you have to scream them more.

 

[Wytboi]

Rich and lean refer to air/fuel ratio, not oil/fuel. Too much fuel is what fouls your plug, not oil.

 

[FruDaddy]

OK fair enough. But in a 125 I like to run more oil in the gas to be safe because you have to scream them more.

That's cool and I don't blame you. It's usually better to err on the side of lubrication as long as the carb is jetted accordingly.

Too much fuel is what fouls your plug, not oil.

True to an extent, but if the oil isn't completely burning (too much oil), it will coat the plug and cause problems. Every oil manufacturer seems to have their own mixture recommendation, and you should stay close to that, but a little extra shouldn't hurt.