What "color" should the spark plug be? Morini Specifically

Discussion in 'Morini Bicycle Engine' started by 2239968, Feb 14, 2012.

  1. 2239968

    2239968 New Member

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    Road my boxer around for the first time last night and today. Starting to run really well. Have not dealt with a 2-stroke in awhile so wanted to get some opinion on my plug. Probably 20-30 minutes total runtime and this is what the plug looks like.

    [​IMG]
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    [​IMG]

    have not really gone past half throttle yet.
     
  2. DaveC

    DaveC Member

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    The tan color is right. White is too lean or too hot. Black is too rich or too cold of a plug range. It looks like your right on the money :)
     
  3. 2239968

    2239968 New Member

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    always a good feeling. Hopefully tomorrow I can get enough runs in that I can get a better idea of its tune. On a side note I am going to check the head bolts tomorrow. The manual says 12-14 nm or 9 ft lbs. Seems low or am I just really tired?
     
  4. DaveC

    DaveC Member

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    If your studs are the 6mm ones that's the right torque. It's actually a fairly small size but it's been used for years on 50cc motors. A lot, mostly really, of the 66's have an 8mm stud.

    Just come up to torque in stages and use some kind of repeating pattern to torque. I use a "Z" shaped pattern or you can use a "X" pattern.
     
  5. 2239968

    2239968 New Member

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    got a lot more riding on the bike today. the plug now looks like this.
    [​IMG]

    Also Can't really go past half throttle once its up to speed. It cuts out. I think it is starving for fuel. I think it might just be because my tank wasn't venting but I ported out the holes in it. Didn't get a chance to test though. My mock shock broke and now I have a booboo on my leg.

    [​IMG]
     
  6. Ibedayank

    Ibedayank New Member

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  7. 2239968

    2239968 New Member

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  8. Ibedayank

    Ibedayank New Member

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    2239968

    post us a pic that shows the middle of the plug
    when you feel the plug it should not feel oily at all but dry
     
  9. 2239968

    2239968 New Member

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    of the electrode? I would definitely say the plug is dry. At first thought that was a bad thing but guess not. Tuesday when my shock comes I will be able to test the engine again. Hopefully the cutting out was the bike just starving for fuel at higher rpms. Everyone that hears the bike says it is pretty quite but when you are on it that is not the case. I can't really judge what the rpms are at by half throttle. rear sprocket is a 55 and the front a 10 with a 24" wheel. Should be capable of a lot faster then I have taken it. Pretty sure the gearing makes it capable of 36 if I am doing the math right but since it cuts out past half throttle I doubt its going faster then 20-25
     
  10. thatsdax

    thatsdax Member

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    That Gray Color is not good. You are way too lean. Gray means you are cooking aluminum and it is becoming deposited on the tip of your plug. You are way hot !! You need to start out safe. That means.. Rich !! And then work your way towards the toasty brown color. Mix 25:1, put in the next fatten up your jetting until you get some 4 stroking.. Once you find this point, then put in the previous jet that had minimal 4 stroking mis firing which ever you want to call the misses. My factory Race Kawasaki recommends never leaner than 32:1. So.. To be safe, work towards this goal of 32:1 if you like. Bottom line here is to be safe and not damage engine. Running too rich you can fix more easily than a hole in the piston. A gray plug is telling you that you are headed towards a hole in the piston !! Fatten up now !! And then work your way towards a cleaner more powerful burn rate.. Enjoy the ride.
     
  11. 2239968

    2239968 New Member

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  12. 2239968

    2239968 New Member

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    ok took a new pic just a bit ago. Didn't run it or anything. This is grey? I feel so worthless .kick2

    [​IMG]

    also the jet in it is a 94. what size jets should I order? was thinking I would order three or four. Probably 96,97,98 unless someone more knowledgeable wouldn't recommend a bigger jump
     
    #12 2239968, Feb 19, 2012
    Last edited: Feb 19, 2012
  13. thatsdax

    thatsdax Member

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    Yes.. Order those jets,, Start out with the largest one and work your way back. Grey color is not good. Toasty Brown is good and what you want. Also.. You can get an infra red Thermometer as checking running temps can also help. Cylinder head temp Ideal should be 375-385 degrees. 410 degrees or higher will burn your engine up. Measure Exhaust temp approximately 3 inches from Ring 1175-1185 is perfect. Enjoy the ride.
     
    #13 thatsdax, Feb 20, 2012
    Last edited: Feb 20, 2012
  14. NunyaBidness

    NunyaBidness Active Member

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    I don't see any grey to that plug. It looks just fine to me.
     
  15. robin

    robin Member

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    Take it to your local small engines guy and show him to get his opinion before spending money --and don't feel worthless were all worthwhile in God's eyes ! Don't belittle youself !
    Mistakenly when i got my engine i left the plastic pin in for a few miles before noticing it -- also i had to vent the tank i got the SCSW BOXER
     
  16. Jumpa

    Jumpa New Member

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    i HAVE A SHOCK THAT JUST MIGHT FIT THAT!!
    it came off an old MB Ihad
     
  17. Jumpa

    Jumpa New Member

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    man you trying to kill yourself anything is better than that wood ever a screen door plunger would be better than that set up lucky you only hurt your leg my shock is too small for that I just dug it out find a straight piece of steel or something stay away from the wood before you end up with it up in your rear end so to speak OUCH " not a pretty thought !! What size rear tire is that Motorcycle tire looks like
     
    #17 Jumpa, Mar 2, 2012
    Last edited: Mar 2, 2012
  18. vachon644

    vachon644 New Member

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    That plug looks on the rich side to me, however since you mentionned power cutouts, the air/fuel mixture might be varying with time which would make it impossible to know if everything is right by checking the plug. If your fuel tank did not vent properly, it is possible that your air/fuel mixtures goes from rich (when the carburetor floatbowl is full) to lean (when the floatbowl empties itself with time as a vacuum creates itself in the tank). That would both cause a rich AND a lean mixture. In case of doubt, open up the carburetor floatbowl and check for the float/valve proper operation : fuel should fill the floatbowl when the float is held down and should stop filling when it's held up. I would do that for my chinagirl so I strongly suggest you doublecheck that since you have a beautiful italian girl!
     
  19. 2239968

    2239968 New Member

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    engine is still running rich. went from a 94 to a 93 and it still isn't running very well. from 1/4 throttle to 3/4 throttle is just dead. Feels and looks like it is loaded up (to much fuel) lots of smoke at this throttle level. If I hold it full throttle it eventually takes off and is fine as long as you keep it 3/4 to full. Leans out when holding full but can go a lot leaner. Still isn't revving up top high enough. Without a speedo I really doubt I am any higher then 25-28 full out. Any ideas?
     
  20. Goat Herder

    Goat Herder Gutter Rider

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    A W7 needle might help your flat spot? I know I am at a much higher altitude myself so I went to a leaner atomiser as well. There for we may not be on the same page? I battled a flat spot that sounds like yours? That drove me batty for a while. I can make these motors totally do my bidding now!

    The W7 needle is much fatter and needs a little bigger main jet. Being that it is a fatter needle the lower throttle range is subsequently leaned out. What it did for me was fix my whole range and let me keep a powerfull high clutch stall with a very nice cruising speed to boot. Somtimes I can go as slow as 5 miles an hour with about a 8000 RPM stall but I am tuned for the best drivability and maximum brute power in my set up.. 24'' wheel 52 tooth sprocket 11 tooth drive.. I can run the lower throttle posistions without any hassle ,no hesitation just a smooth transistion.. My motor will still load up a bit if it is left to Idle for a while but what I have now is sweet,, very managable!

    My experiance in the begining was bucking hesitating etc Untill I put more throttle and waited for it to clear out. But I am at 6000 foot above sea level. Harder to tune when yur practically half way up the himalayas lol.

    Do not lean out your main jet to the extent that there is no occasional 4 stroking with out a load. What I mean to say is on a hill you will want the slight richness for better power. If in its sweet spot on a flat away no real load it should 4 stroke a bit at your full most throttle posistion ''WOT''. ''This is your safty Zone!''

    Get a hot plug in there too. Might help . NGK B10 is what I run with my DH.

    In my experiance the bigger powered Morinis Idle sweet! Just not for long before loading up. This is of course the Morini with the bigger PHBG carbs 19 and 21 mm. They put out way more power with these larger carbs and the 4 peddle reeds tho.
     
    #20 Goat Herder, Mar 13, 2012
    Last edited: Mar 13, 2012

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