Help. 1999 Yamaha 40 3 cyl

Discussion in 'Boats, Blinds, & Gadgets Forum' started by BadBowtie, Aug 23, 2009.

  1. BadBowtie

    BadBowtie Elite Refuge Member

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    Got a 1999 Yam 40 2 stroke 3 cyl. Had carbs cleaned early march. Ran/idled fine for few time out. Sat for a while and ran some older gas thru her not too long ago (2-3 month old gas). Made a new tank up today of 50:1 6 gals and she still want to die at idle. Almost like it is missing..... rev a little above idle and its fine. Last time it did this the top (1st?) plug was foulded bad. Also the plugs are new NGK's. Any ideas. No I did not check the plugs when I put it up today. But will check here soon.:z
     
  2. 1995 US1

    1995 US1 Moderator Moderator

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    Change plugs
    Drain carb bowls
    If problem not solved, remove and clean carbs. While you have the carbs off, check reeds. A split reed will make it not want to idle.
    D
     
  3. BadBowtie

    BadBowtie Elite Refuge Member

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    Thanks will look at it
     
  4. kdog

    kdog Elite Refuge Member

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    Cleaned carbs .....as in took the jets out ? take the jets out and clean thoughly
     
  5. BadBowtie

    BadBowtie Elite Refuge Member

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    will find out today
     
  6. 1995 US1

    1995 US1 Moderator Moderator

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    When I say "clean carbs", I mean do it properly. Remove the carbs, completely tear apart, soak all metal parts in carb cleaner, rinse, blow air through all passages in jets, pickup tubes, carb bodies, to include the progression holes in the carbs and tubes.
    D
     
  7. BadBowtie

    BadBowtie Elite Refuge Member

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    So I went and got 3 new plugs. Gaped them at .040 like the manual said. She started and dies that was it. So I put older plug (from march, that were gaped at .020) and she would not start. Made sure fuel was getting from tank all the way thru filter and pump, it was. Next noticed the small red lever on carb number 2 (the emergency enrichment) it was in the normal position and so I put it in the Open position. She fired right off. Next looked online and found that the solenoid from the emergency enrichment should have 2-3 ohms on it and 12 when key on, it did on both. So what the heck is this emergency enrichment deal, i assume it should stay on normal but she wont run. She runs fine and idles down when it is on "Open" fine, but seems to smoke a lot and run rich.
    Danny, or anyone else have any ideas?

    see pics below of "emergency enrichment lever"

    [​IMG]

    [​IMG]
     
  8. blowdown

    blowdown Elite Refuge Member

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    not positive, but the emergency enrichment is for cold starts. It chokes the carbs and pulls more fuel in. The reason it runs right when it is on is because your idle jets are clogged. Pull the carbs, clean'em, put em' back on, and go to the lake.
     
  9. 1995 US1

    1995 US1 Moderator Moderator

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    Yep, what he said>
     
  10. BadBowtie

    BadBowtie Elite Refuge Member

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    Thanks guys will do that, but why would the mechanic i took it to gap the plugs to .020 instead of .040 like stated it should be....?
     

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