rm 85 plug fouling

[rmrider45]

new top in in my sons rm 85. strange thing is if he rides it hard over the weekend track or trails and i leave the bike sit (for a week)it fouls the plug.the bike will try to start then die.i pull the plug out it is dry but black in color.could this need a adjustment on the card to make it less rich .atm there is a b10es plug in the bike. in another thread http://www.dirtrider.net/forums3/showthread.php?p=1340699#post1340699 they tell me to put in a BR10EIX.
not sure if the plug will solve my problem. also i am running the gas/oil mixture 50:1

 

[IndyMX]

Maybe you should run the manufacturer recommended 32:1 and jet the bike properly..

 

[rmrider45]

:bang: :bang: the bike was jetted from last owner.and running the bike 50:1 will cause the plug to foul?i would think not enough oil.seems that bike running with 32:1 it smoked to much
:ride:

 

[IndyMX]

:bang: :bang: the bike was jetted from last owner.and running the bike 50:1 will cause the plug to foul?i would think not enough oil.seems that bike running with 32:1 it smoked to much
:ride:

despite what you might think, the oil ratio has nothing to do with plug fouling.

what you are doing running 50:1 though, is starving that engine of oil. Which is bad for the crank bearings.

Give it the proper amount of oil, then jet properly, and you will be happier.

If you're fouling plugs, it's pretty obvious that the previous owner didn't have it right. Regardless of what he said, if your plug is coming out black, that's rich..

Read up on jetting and do the job yourself, and you'll save a lot of headaches.

 

[dirtbikerider123]

you are changing the ratio instead of jetting it. 50:1 is hard on your bike. switch to 32:1 and take it to your mechanic to get it jetted.

 

[IndyMX]

you are changing the ratio instead of jetting it. 50:1 is hard on your bike. switch to 32:1 and take it to your mechanic to get it jetted.

If you rely on a mechanic to jet your bike properly, you're going to spend a lot of money, since jetting is so dependent on weather and other factors.

Learn to jet yourself, and you'll not need a mechanic to do it for you.

And with a handful of jets, you can easily keep your bike jetted properly for about any condition you ride in.

 

[dirtbikerider123]

If you rely on a mechanic to jet your bike properly, you're going to spend a lot of money, since jetting is so dependent on weather and other factors.

Learn to jet yourself, and you'll not need a mechanic to do it for you.

And with a handful of jets, you can easily keep your bike jetted properly for about any condition you ride in.

no, i would never let a mechanic touch my bike, im just telling this guy to take it to a mechanic cause..... :cool:

 

[rmrider45]

lol thx for the replies .by trade i am a mechanic and a auto body man.well we rode the bike this weekend hard and it starts fine . after all the plug wasnt fouling.:) i think the carb was dirty and from sitting . i do all the work on my sons 85 and my 125. i will try the changing to 32:1 tho this upcoming weekend ..btw we mainly ride in the coal hills so cleaning the air cleaner and carb often is a must . i just forgot to clean the carb good when i put the new top end in over the winter.. :bang: :bang: :bang:

my son on his 85 bored to a 105

http://www.youtube.com/watch?v=oMW5QxLIzuI
http://www.youtube.com/watch?v=73S9FO8pzik

hes only 11 years old :)

 

[Matt90GT]

50:1, 40:1, 32:1, 24:1

They can all be ran in bikes. Even up to 100:1, but you have to be using oil designed for that mixture first, second the motor needs to be designed within the oiling parameters. I have run every 2 stroke on synthetic amsoil premix at 50:1 without ever a oil related failure .

But my point is reguardless of what ratio you use, you have to jet the carb for it. 50:1 is a richer mixture than 32:1. So by just switching mixtures you are really messing with the jetting of the carb. Like indy said you need to learn how to read the plug and jet the bike properly. Especially learn how to properly tune the air screw for temp and weather variables that happen from day to day. So dont just go changing the mixture hoping this will magically work better.

 

[hot125mod]

I never had good luck with the amsoil dominator mixing it at 32:1 all I did was foul plugs and i'm jetted spot on. and 50:1 is just too lean, but the amsoil only seems to work at 50:1 thats what the bottle says to mix it at too.