250-500cc spark plug advice

Hey Guys,

Just pulled the spark plug in my 05 wr250. Can someone confirm i think i have been running a little to much oil in my fuel:




do husky's run a special spark plug? old plug on the left and new plug on the right. This is what the bike shop gave me, but im struggling to get it to hook up.



cheers
Glenn

Man, it's the same plugs but your old plug without cap, you can remove the cap of new plug.

ha really? so a set of vice grips on the end and it should twist off?

do all husky spark plug leads only take the small thread? or am i just being weak and not jamming the larger end in the lead hard enough?

i dunno about all, but my 125 requires that piece to be spun off with vice grips...

It's not really about running to much oil in your gas... People run different mixes... I personally run 40:1, what the manual suggests, but I also hear of people running 32:1, or as little as 50:1.

What your looking at is the ratio of fuel to air, and has to do with jetting, more than oil:gas ratio.

It does look like you may be running a little rich (to much gas/oil, not enough air), but it's better to be on the rich side than the lean side.

twenty, your plug looks rich. Once you get it leaned out the combustion process will make more heat and burn off the oil even at 25:1 mix. When it's too rich the combustion temp is too cold and the oil won't burn which leaves the plug greasy and will spooge up your pipe and silencer. Remember you can be lean on one circuit and rich on another so pay attention what position the throttle is in when you are assessing which circuit to lean out or richen up.

You will need to decide on what oil ratio to use before jetting. Using a ratio of say 32:1 will give you a leaner jetting than would 50:1, therefore decide what you want to use then jet accordingly. Personally I use 50:1 Motul 800 which has been perfectly good with nothing but normal wear in the last 1500 miles.
As Lankydoug mentions pay attention to the throttle position when checking your jetting, it is a good idea to actually mark the throttle housing and rubber with throttle closed, open fully and mark the rubber against the housing, then also mark of quarters and half.

You can then check while you are riding where the throttle is in relation to how its running. There is a great deal of info in jetting chat on how to jet your bike correctly.
It is surprising the difference correct jetting makes - from riding a pig to a race horse! even the basics like starting issues are usually resolved.

Not to hijack the this thread but I was wondering what plug most people are running. My bike had a B8EG in it when I bought it and I have stuck to that, but the owners manual says to use a BR8EG.

An 8 or a 9 is ok the nine is colder so depending on the kind of riding you're doing you can pick what works for you. The R means resistor and on the older ignition it is not needed it it would be better on the newer digital ignitions. I have used 8s and 9s with and without the resistor and could tell no difference in performance. If you are using pump fuel the 9 might be better to prevent pre-ignition. I use VP 110 and it all works for me.

Thanks, I run Cam 2 in my bike so no octane worries. I was wondering if running an R plug would add too much resistance to the circuit and weaken the spark. I always ran R plugs in my Jap bikes.

The R plugs were made to minimize radio interfearance, the resistor core prevent magnetic lines of flux from inducing voltage in electronic devises. They don't hinder performance any measurable amount.

If you have TPS, Digital Ignition and like to run in the high rpm land then get the 'R' plugs as the electrical interference can cause misfiring. Other than that, the non R plugs are fine to use.

Whether you run an ES, EG, EGV or iridiums..poor jetting causes fouling and not plug type or oil mixture.