Still fouling plugs...

[jblalock]

I have a 2002 KDX 220 with airbox mods, twin air filter, FMF Rev pipe and Turbine Core II silencer. It is jetted per CD's recommendations with 145 main, 42 pilot, needle in second position from top and air screw 1.5 out. I am running premium pump gas with PJ1 Goldfire mixed at 32:1.

The bike bogs a little down low. I do a fair amount of slow riding with my boys who are 7 and 4.

I have fouled plug the last three trips out. and have alot of spooge.

Any suggestions? I have read the carb runing article.

Thanks in advance.

 

[BradFrost]

You can lean that mix out slowly up to 40:1 with safety. Put a performance plug in it too... might seem like alota cash for a tiny bit but it's worth it. Just don't go too lean and remember to check your carb settings when the conditions change or bang! goes the weasel :ride:

 

[John Harris]

Riding slow a lot of the time--it seems to me that you are one or two sizes rich on the primary jet. Do as above and go to 40 to 1 mix with all synthetic motorcycle oil and try a leaner primary jet. You did not say what plug you are using, but go to an NGK BR8ES. This seems to be the standard that most KDX's use. 8 is the heat range number--9 is colder and more likely to foul especially at slow speeds. 7 range would be hotter plug and could cause engine problems if you chose to ride the bike hard. You are close make a few more adjustments and really enjoy! Cheers John

 

[jblalock]

John, I am using a BR8ES (actually several of them). When you say "primary jet" do you mean the main jet or pilot?

One other item I for got to mention, The bike will sometimes leak fuel from the overflow (peeing), but does not do it all of the time. Will this cause a rich condition or is it just a nusance/waste of fuel? It has not done this since I pulled the card apart to check the jets and cleaned everything, but I suspect my float need to be adjusted.

Thanks

 

[oldmanmike]

This sounds like the same problem that I'm having on my '85 KDX200. It's done this since I bought it 10 years ago. Let me know what you find out. oldmanmike.

 

[Green Hornet]

For slow riding go to a BR7ES that should help. If not lower the needle One notch and try if. You can also go smaller on the pilot jet. Try in this order. Remember the needle adjustment will have an effect on the entire range. BR8ES is the Standard plug and as per service manuel it states to go to the BR7 if fouling occurs

 

[jblalock]

Green Hornet-- Thanks for the info. My clip is in the 2nd from top position on the needle. Do you think that placing in the third position is the way to go? That is what the FMF website says.. neddle in third position from the top.

Thanks

 

[Rhodester]

Fix the peeing by dropping your fuel level (ie. float level) 2mm. That'll take care of it assuming that your needle and seat are seating properly.

 

[Braahp]

Try a BR8EG plug. Won't foul.

 

[jblalock]

I thought that changing the ratio from 32:1 to 40:1 would make my rich condition worse?

Braahp, shouldn't I be able to get it to run w/o fouling using a BR8ES? Or am I asking too much considering the amout of slow riding I do?

 

[Knetman]

I had exactly the same problem... every time the bike fouled, I would remove the plug and it would be caked in oil and stink of fuel... and that's running 50:1 Motorex synthetic. Adjusting your ratio isn't where you're problem's at... I'd say as above to go with a leaner jetting setup. Or as I did, try winding your airscrew out a turn or so... just make sure you stay on the rich side of things. Much better to run a little richer and know you're looking after your engines internals, than to run lean and be lacking sufficient lubrication.

Hope this helps...
Tony

 

[John Harris]

Yes, the primary and pilot jets are the same jet. You should be able to run the BR8ES wo fouling in my opinion, IF your set up is correct. The high float can cause flooding and fouling--fix it. Next to the top clip ring on the needle is usually the correct position--the middle clip position will raise the needle in the main jet and make your bike run richer.
As far as fouling is concerned the main thing is synthetic oil not whether it is 32 or 40 to one. Yes 40 to one is richer than 32 to one, but contains less oil per fuel fed. This one has been discussed many times--read some of the old posts.
A 7 plug is hotter than an 8 plug=fact. A 7 plug will be harder to foul than an 8. I don't think you are likely to damage your engine with a 7 unless you plan to run hard for a long time like full bore on a paved road in a hurry to get in before the storm or the like. That is why I suggest to get your bike running correctly on an 8 plug--you or another rider cannot forget a 7 is in it and possibly damage your engine.
You will enjoy your project--Cheers John

 

[jblalock]

Thanks fpr the info. I am guessing ,my issues are with the air screw adjustment and/or float level. I will start with float level then get the air adjusted.

Of course, any other suggestions are welcome.

 

[Green Hornet]

JB-What altitude r u. The J U S T K D X Carb Tuning has a graph on the bottom showing altitude n Temp.Use your stock jetting for this calculation to give you your approximate jetting. Then change any jetting as per manufact's instructions as per your pipe setup or reeds, ETC. But they are recommendations. You should do your plug chops and judge for yourself. Its a bit of a pain but its a helluva lot cheaper than a re-build. Try changing your needle position first before anything else, may be your answer

 

[CZ511]

Hello, just a thought.... How much oil are you using on the air filter? To much oil will cause the motor to run rich. Also, check out Golden Spectros' site for a great oil mixing guide. www.goldenspectro.com. I have been using Golden Spectro at 40:1 and never had a problem.

 

[jblalock]

Green hornet, I'm in cent4ral MS so pretty much sea level.

CZ511, That was my thought too. I have only had the bike a few weeks. I cleaned the filter and swiched to NoToil. I removed the excess oil so I don't think that I uses too much oil. I will give that a check though.

 

[CZ511]

Ok, to avoid plug fouling, try this...... Put the bike in second, let the clutch out just as it starts to catch, hold the throttle to the stop and stare at the left side of the starting gate mechanism, where the little pin is holding up the gate to your front wheel. Continue to hold the throttle to the stop, I mean wide open, when you see the pin drop let the clutch out, slide your ass a bit to the rear and race into the first corner, remember, hold on as long as possible and dive into the turn!

No, No, just kidding, I just had a flash back to the late 70's & 80's when I was racing 125 & 250 class! Yes, I'm old & slow now at the age of 43 but still love to ride.

You know, if the plug is really black and there is a lot of exhaust drip maybe the right side crankcase seal is bad. Let's hope not.

 

[BradFrost]

I thought that changing the ratio from 32:1 to 40:1 would make my rich condition worse?

Braahp, shouldn't I be able to get it to run w/o fouling using a BR8ES? Or am I asking too much considering the amout of slow riding I do?

How does that math work.. ?
30:1 = 33.3ml oil for 1ltr
50:1 = 20ml oil for 1ltr

1000/30= 33.3333

 

[G. Gearloose]

uhm, Less oil will make a rich condition worse, lookit up.

 

[BradFrost]

Wow I gotta stop using my hammer and credit card to fix things and read more threads.

 

[jblalock]

CZ511, thanks for the lesson on holeshots. If I rode a little faster I probably wouldn't be having this problem. When I get out by myself (without the kids) and can go a little faster, the bike runs great. Not much smike or spooge. But riding without the liuttle guys is a rare occasion. (BTW, that is not a complaint I'd much rather ride with my boys and go slow than go fast without them anyday.)

And I'm just going to pretend you did not say that about the crankcase seal for now.

Brad, The idea is that the term Rich/Lean applies to the amount of fuel, not the amount of oil. So if you reduce the amount of oil per liter of fuel then you will in effect be passing more fuel. (assuming for a particular jetting setup that the same amount of premix enters the combustion chamber no matter what the ratio) From what I understand from reading other posts, it is unburned fuel that causes problems, not necessarily too much oil. Someone please correct me if I misspoke.

 

[BradFrost]

Yeah I just dug this up..

"To avoid confusion, it may be best to use the terms "rich" and "lean" only in reference to air/fuel ratios. Not sure how to differentiate oil/gas ratios other than maybe heavy vs. light.

More oil in fuel mix will result in a leaner burn due to less fuel
being metered. The difference between 32:1 and 40:1, in respect to A/F ratio effect, is not very great and will not likely harm an engine unless it was on the edge of too lean to begin with."

See what happens when you start on a 4stroke :)
I love this place.

 

[G. Gearloose]

Yup, perhaps 85% of new topics have already been well answered, developed, researched and tested. Ignoring the archives is equivelent to dismissing very smart people that we likely won't hear from again on a new, but beat into submission topic. Its been a while since something truely new has shown up.

There's usually 2-3 active spooge/jetting threads going at a time [sigh]

 

[CZ511]

jblalock, I apologize, I hope my little starting procedures was not takin the wrong way. At the age of 43 I'm having a tough time dealing with getting old and not being able to ride like I use to, actually, not being able to do a lot of things! So, again, I apologize, I honestly was dreaming of the old days. Also, as a side note, I don't ride with my kids 5 & 8 year old girls, but I do ride them on my bike and it's absolutely priceless moments. A 50cc bike may be in the near future. :)

 

[jblalock]

CZ511, Not taken the wrong way at all. I though it was pretty funny actually.