fouling plugs (rm85)

Discussion in 'Pit Bikes & Mini's' started by terrible, Jul 1, 2006.



  1. terrible

    terrible Rookie DRN Member

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    I've been through four plugs in three gallons of fuel. The fuel is mixed 32:1 as I was told. The last plug I bought I used a bp8es insted of the 10. The 8 lasted for quiet a while too. I try not to load the thing up too much as well. Is there anything I can do besides buying plugs by the case?

  2. wayfastwilly

    wayfastwilly Rookie DRN Member

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    plugs

    My sons 04 rm 85 can putt around and idle all day, and has never fouled a plug. How old is your top end? I ran 32-1 but changed to 40-1 because of spooge. Didnt foul plugs on either ratio. 3 :) 2-1 is 4oz oil to 1 gal. gas is that what you are mixing?
  3. terrible

    terrible Rookie DRN Member

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    Yep that's the exact mix I run. My top end is only as old as the gass I've run through it. I bought it two weeks ago and it was a left over. It never had gass in it before I bought it. What plug are you running?
  4. husabutt

    husabutt Rookie DRN Member

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    24NAAF
    24NAAG
    24NAAH-stock
    24NAAJ
    24NAAK
    24NCDF
    24NCDG
    24NCDH
    24NCDJ
    24NCDK

    These are the needles for the RM85. The two above stock are richer and the ones below are leaner.

    I would start with a 24NAAJ needle and the next size smaller main jet to begin your jetting project.

    This is from the Bel Rey website:
    Q: Tech Dude,
    I have a 1998 Kawasaki KDX 200 and I recently switched to your H1R Powervalve Formula and now my bike is dripping black thick oil out of the exhaust pipe. I am mixing it at 40:1. Should I run less oil and mix at 50:1?

    A: Your problem has nothing to do with what ratio you mix your oil at and everything to do with jetting. I recommend you mix Bel-Ray H1R anywhere between 40:1 to 50:1. It is fully synthetic oil and can handle high dilution ratios, no problem. What you are describing seems to be jetting. Somehow your KDX has turned rich and there could be many reasons why: a dirty air filter, warm weather, etc. The oil ratio you mix with fuel will have little to do with changing your jetting that severely. However, by switching from 40:1 ratio to 50:1, you will actually get richer jetting not leaner. More oil in the fuel makes a thicker fuel mixture which will travel through jets slower meaning more air is flowing than fuel mixture, and hence, your jetting will be leaner. Even though this is a slight difference, you will be heading in the wrong direction and worsening your problem. I recommend adjusting your jetting. Have a qualified mechanic help you jet your bike spot on and your dripping problems should disappear. If drooling, dripping and unsightly soiling persist, be aware that these symptoms usually disappear before adolescence. If you reach puberty and find yourself in the same situation, then seek counseling, daily viewing of Oprah and/or support groups. You may find that a group hug and public crying put you in touch with your feelings. It probably won’t help your symptoms, but you’ll feel good about yourself.
  5. j32

    j32 Uhhh...

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    here is a good solution- use klotz oil-40:1
    run for a while check the plug look at the color it should be golden brown,not black or wet
    jetting and depends on how you ride the harder you ride the more lubrication you need
    if the oil isnt burning,changing the jetts to bigger will allow more fuel, and oil-not just fuel
    klotz burns clean
    check you crank case oil level to see if your bike is burning crank oil as well !!!!!
    if so the oil seal is blown and needs to be replaced
    this might be the problem,and is not too hard to fix usually
  6. robwbright

    robwbright Rookie DRN Member

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  7. terrible

    terrible Rookie DRN Member

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    Thanks for the good info guys. I've never messed with re-jetting a bike so this should be fun. I've delt with the two-stroke diesel engines in r/c cars for over 20 years but with them it's only two needles to mess with.

    Thanks again!
  8. yz_rider_30

    yz_rider_30 Rookie DRN Member

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    Try using a b9es spark plug by ngk.
  9. oldguy

    oldguy Always Broken

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    Beware of this experts advice :think: I am personally not sure of the requirements for RM85 plugs but from what little I remember there is a differance in thread lengths between the B9, BR9 and the BP plugs. YZ rider likes to throw out use this plug in threads and it will solve not only fouling and spooge but world hunger as well
  10. terrible

    terrible Rookie DRN Member

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    I've been using a bp8es for a while. It works for a bit but after three -four rides (three hours) I'm still fouling the plugs.
  11. Vic

    Vic ***** freak.

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    FWIW- I used a B9ES in mine. If I remember correctly, I dropped the needle (raised the clip) one or two positions from stock and went one size leaner on the pilot jet. I used the same plug for the two years that I had the bike.

    You can probably go leaner on the main too, but that's not what's causing the fouling.
  12. spuddy

    spuddy Rookie DRN Member

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    i have just had the same problem with my sons 2004 rm 85
    i have a vforce reed block fitted from when i got the bike . when we took it out it was smokey and boggy and it had a splutter like it was to rich . i put differant main jets in but i ran the same . what ever i did it didnt seem to fix the problem
    anyway it ended up in the end being the crank seal on the clutch side replaced that everything was ok smoke had gone and ran great
    40.1 premix
    125 main jet
    50 pilot
    standard needle 3rd grove
    1/12 turns out on mix screw
    hope that helps
  13. terrible

    terrible Rookie DRN Member

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    I changed out the main jet last week but I have yet to have a chance to ride. Hopefully that will help a bit. Since I switched to 40:1 last month it seems a bit better. I also cleaned the air filter. Suzuki must get free filter oil 'cause the use alot of it!
  14. j32

    j32 Uhhh...

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    jetting isnt going to solve -mixing too much oil
    unless it is oil injected
    is it drooling oil?
    what does the plug look like -?
    is it oily?--or wet from too big of jets?
    i have used a lot of different oils,and klotz is the best that i have found-it burns cleaner,and helps remove carbon build up-great for powervalvs.
    and you will see the differance when you rebuild your motor
    change the silencer packing ,it is probbably full of oil,and holding too much back pressure in,and clogging up the cylinder= a fould plug
    i would change the packing ,try diff oil,then worrie about the jetts
  15. j32

    j32 Uhhh...

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    squeeze out the exess oil in the filter !!!-- in need to get air through there
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