I think I need help. Bike Running too rich?

Discussion in 'Motorized Bicycle General Discussion' started by The Motor, Feb 3, 2013.

  1. The Motor

    The Motor New Member

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    I need help. Bike Running too rich?

    Hey Guys

    I just recently installed a flying horse motor which i purchased from Bike Berry. I installed everything thing and she runs and idles(after a lot of tweaking) but it seems the bike is not running right. First off I think the bike is running too rich, below are pictures of the spark plugs I installed on to the bike(Not plug chopped, after normal riding). The bike also sounds "rough" Here is a link to a you tube video of the bike with the motor running. The You Tube Link

    Here are the things that I have done so far to make it run less rich and to smooth things out.

    1. I opened the carb and took the side clip with the C Clip on it and I set it to the leanest mix. Here is the guide that I used Carb Guide

    2. I adjusted the float inside of the carb and lowered it....twice. Not sure if I should lower it any more.

    3. I replaced the stock wire and boot with a new wire and boot. It has a copper core(Stranded wire) with a coil inside the boot.

    4. I gaped the spark plugs to all different sizes. 0.020, 0.025, and 0.030. Setting the spark plug gap to the smaller sizes seemed to help a little(with spark plug color still oily though) but the engine didn't feel as "smooth".

    5. Used different spark plugs namely the NGK BP6HS and the NGK B6HS.

    6. Used a leaner fuel mixture. Instead of the 16:1 in the manual its running on 32:1 fuel mix. So I mixed 4oz( half a cup ) of oil to 1 Gal of gas exactly. I also replaced the plug with a new one afterwards. Included pictures below.

    7. Used different types of oil. At first I used Outboard 2 Cycle oil( I was told this was the best to use). Then I switched to Universal 2 Cycle Engine oil( Currently in the bike). Pictures below.

    8. I messed around with the Idle scew. It seemed to only help the idle though. Which is to be expected I guess. I included a picture of it below anyway.

    I'm not sure what to do next really. I also read that in some article that it's good if the plug is dark and oily. I'm not to sure about that though. I believe its supposed to be a brow/tan color? Let me know what you guys think and any help would be very greatly appreciated. Thanks.

    BP6HS Gap = 0.030

    [​IMG]

    B6HS Gap = 0.025 (I rubbed some of the oil off it on accident)

    [​IMG]

    Idle Screw

    [​IMG]

    Previous Oil

    [​IMG]

    Current Oil

    [​IMG]
     
    #1 The Motor, Feb 3, 2013
    Last edited: Feb 3, 2013
  2. GearNut

    GearNut Active Member

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    1. Never use outboard engine pre-mix oil. Outboard engines are water cooled via the cold lake or ocean water that is pumped through them and operate at much cooler temperatures than air cooled engines and have far different thermal protection needs.
    The universal oil you are using now is much better suited for your engine.
    2. I have one very big issue with that tutorial video by BikeBerry. When doing a plug chop the engine needs to be under a load, ride the bike!
    Just revving the engine at a standstill will not provide the real world conditions that are needed to properly color the spark plug. The engine is not doing any work while at a standstill, just merrily spinning faster.
    Ride the bike for 1/2 mile or so holding the throttle at the position in question then at the same time pull in the clutch lever and hold the kill switch until the engine comes to a complete stop. Do not let the engine idle or run what so ever. Doing so will ruin the color print on the spark plug. Let the engine cool for 20 minutes or more before removing the spark plug. If you remove the spark plug from a hot engine you risk damaging the threads inside the soft aluminum cylinder head.

    3. Most engines run a little rich at idle speeds. If you are checking the color of your spark plug based on just idle speeds expect it to be darker than desired.

    It is supposed to be a cardboard brown to milk chocolate brown color, not black and oily.
     
  3. The Motor

    The Motor New Member

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    Thanks for the reply! I'll do the plug chop straight away. Should I replace the old spark plug with a new one or is it ok to keep the current NGK B6HS in there.

    Also does it sound like the motor is 4 stroking? I'm new to this so I can't really tell.
     
  4. Kioshk

    Kioshk Active Member

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    Yep, that "outboard" 2-stroke caught my eye as well. Who told you it was the best for these engines?

    Is this an NT crarb? What size is your jet?

    Trust me, you'll KNOW if you're 4-stroking, even if you've never felt it 2-stroking. 4-stroking is rhythmically jerky while 2-stroking is smooth. It reminds me of when I was being examined my doctor. He had his hand pushing up between my balls, and told me to "push...like you're giving birth". I did it right apparently.
     
  5. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    I always tell customers to ran about three gallons of gas through their new engine before worrying about trying fine tune the carb, because the engine will keep running better & better the more it breaks in! (& it might not even need any carb changes after it's done breaking in). ;)
     
  6. 2door

    2door Moderator
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    I concure. I never expect an engine to start performing until it has at least two hundred miles on it, and even then I can expect better with 300. All of the symptoms you describe are those of a new engine that isn't broken in yet.

    Also everything Gearnut said should be followed. Do not run outboard oil in an air cooled engine. And do not run the 16:1 oil mix that so many 'instruction books/videos' recommend.

    The idle speed screw on the NT carburetor has no effect on how the engine runs. It is a simply mechanical function that determines how far open or closed the throttle is at the idle position.

    Tom
     
  7. The Motor

    The Motor New Member

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    One of the guys at a local lawn mower repair shop in town. He said he specialized in small motors so I believed him. My bike is currently using the universal oil now.

    Yes it is an NT carb. I have no idea what the jet size. How can I find out? It's whatever came with the carb.

    I think I am 4 stroking then because it is the opposite of smooth sounding atm. I'll do the plug chop first though to make sure that it is really rich. Problem is I need to find 0.5 miles of road that won't force me to stop and idle the bike. I'll post pictures when I accomplish this.

    Also do I need to put in a brand new plug for the plug chop?
     
  8. The Motor

    The Motor New Member

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    I contacted a local motorized bike shop here in town and they said that it would be bad for the motor if it got used too running rich. Would going through 3 gallons of gas with the motor being rich hurt the motor?

    Also the bike is really really hard to start. I usually need several attempts going down hill at high speed to get her started(with choke). Is this typical of a new motor as well? If not, how do I fix this? Could the CDI be going bad? I say this because I tried to start her once but the boot on the spark plug came off with out me noticing. I read somewhere that this could cause the CDI to go bad.
     
  9. GearNut

    GearNut Active Member

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    Using a brand new spark plug when doing a plug chop is a good idea, but not necessary unless you are a tuning purist.
    If the engine is indeed running too rich then using the choke when starting it will make it run waaay too rich and starting will become nearly impossible.
    Try starting it with no choke or at most 1/2 choke.

    Running a CDI ignition without the spark plug in a proper and complete electrical circuit is not good for the CDI, but they usually can tolerate a bit of abuse before giving up.
     
  10. BigBlue

    BigBlue New Member

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    Follow all the above advice from the above posts and you'll be fine.

    Chris
    AKA: BigBlue
     
  11. dodge dude94

    dodge dude94 New Member

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    I think the most problems a 2 stroke will have from running rich is a stopped up exhaust and air filter.

    Mine ran rich and lean until I pulled the vent tube, changed the needle position, and float level. Granted, I DO have a CNS carb, not an NT.
     
  12. The Motor

    The Motor New Member

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    I managed to do an actual plug chop. This is what it looks like. I guess she was really running too lean.

    [​IMG]
     
    #12 The Motor, Feb 5, 2013
    Last edited: Feb 5, 2013
  13. Scott.D.Lang

    Scott.D.Lang Member

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    Ill be keeping a eye on this post because Im sure Im about to run into many of these problems myself lol

    Oh and a question about the cdi would it be possible to use one from something else like a motorcycle or a car? I ask because I've never used a stock coil on anything lol.
     
  14. dodge dude94

    dodge dude94 New Member

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    That's weird.
    If it's running too lean, try richening the mixture up with the needle valve and pulling the bowlvent tube.
    There used to be a 80cc dirt bike coil guys would put on.

    I think Jaguar has something like that...
     
  15. Greg58

    Greg58 Well-Known Member

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    The brown on the plug where the oil has burned off seems to be the right color, one way to check if its rich is to do a test run without the air cleaner on. If it runs better it is probably rich and needing more air or less jet size, but don't run it without the air cleaner for long.
     
  16. The Motor

    The Motor New Member

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    Where is the bowl vent tube located? Here are diagrams of the innards of the NT carb. Carb Diagram I don't see it. Hopefully I didn't overlook it.
     
  17. GearNut

    GearNut Active Member

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    I say that it is running rich and you need a one point hotter spark plug.
    The black on the plug tells that the state of tune is rich, the 1/2 clean 1/2 black tells that the spark plug is too cold to completely keep itself properly clean.
     
  18. Greg58

    Greg58 Well-Known Member

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    The nt does not have the vent tube. The bp5hs is one range hotter with the extended tip, it runs well in my engine.
     
    #18 Greg58, Feb 5, 2013
    Last edited: Feb 5, 2013
  19. Groove

    Groove New Member

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    With my gas RC cars, when they were running too rich they would bog down when throttled, and smoke a lot at idle. They'd also run on the cool side. Just my inexperienced 2 cents..
     
  20. dodge dude94

    dodge dude94 New Member

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    Whoops, my bad. Disregard what I said about the bowl vent, didn't notice you had an NT.
     

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