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  1. #1
    Seaman Apprentice
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    May 2012
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    Default Mercury 150 XR6 hard to start!

    Ok guys here we go again. I had u all help me figure out some trouble on my buddies boat which had a Johnson GT150 a few days ago.

    Well yesterday i went and baught my own bass boat. 1992 Stratos with a Mercury XR6 150. Very nice setup and guy i got it from said it has been a excellent boat.
    Well, i take it out today and had a lil trouble getting her started. Finally did. Figured it was just bc of it being 2 stroke and cold natured. Well, idled along and opened her up to plane out and noticed it hit rev limit twice before it planed out. Took it a lil bit of time to plane also. Like it wasnt making much power. Ok, get where im headed shut her down for maybe 30mins. Went to start again wouldnt start. Ended up taking plugs out and turning it over to clean pistons out. Rrinstalled and took about 4 tries and she fired up. Went a lil ways and shut her down and she done the same thing. I only reached 50mph and a lil above 5k on tach. What do u guys think it could be?

    At the end of the day i had to towed back bc i ran battery dead tryin to start her up. Called ol buddy and he said he has never had a problem with it. Checked compression and got a steady 110psi on all cylinders. When i got back home i changed battery and she started right up. Killed it 6 times and she would fire up every try. Got me puzzled. Read about vapor lock and how they need to be richened up before start.

    My bubble was pumped tight when she started and i noticed when it wouldnt start i could pump it a couple times to tightness. What your thoughts?

    Sorry for all the mummbo gumbo.

  2. #2
    Supreme Mariner
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    Default Re: Mercury 150 XR6 hard to start!

    50 MPH and above 5K RPM is about what you should be getting. It never should hit high RPMs when getting on plane. Likely prop is ventilating. Maybe carbs are allowing motor to flood?

  3. #3
    Seaman Apprentice
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    Default Re: Mercury 150 XR6 hard to start!

    i think it might be the carbs also. It is really smokey when u first fire it up without chokin it. Gonna take carbs off and let them soak in cleaner. It will fire up everytime u pump the bubble and hit the key. think maybe there is a small leak somewhere also. Gonna go check fuel filter in a min.

  4. #4
    Seaman Apprentice
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    Default Re: Mercury 150 XR6 hard to start!

    My motor also has one of those big fins on it that is supposed to help out. Would it be better to take it off? My buddy says it helped his run faster and better without it.

  5. #5
    Seaman Apprentice
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    Default Re: Mercury 150 XR6 hard to start!

    ok guys went out and tried to start it today and she tried but thin wouldnt. Just turned over and over. I eventually took plugs out and turned it over and cleaned it out. Reinstalled and after about 8 tries she stumbled to life. Pretty much everytime it want start i can take plugs out and clean her and she will fire up. Should i just try starting it with out useing the choke? Might be dumping to much fuel.

  6. #6
    Petty Officer 2nd Class bobkyle2's Avatar
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    Default Re: Mercury 150 XR6 hard to start!

    How old are the plugs? I have to choke the crap out of my XR6 if its been sitting a few days...And pump the primer bulb, But once its started that one time it will start the rest of the day and usually the next day without pumping primer bulb..The bulb should stay tight. If its not staying tight after just a few mins.. I'd say your float valves in carb are letting the carbs bleed down into the cylinders.

    If the fuel line and primer bulb look old... I'd suggest changing that.. From the tank all the way into the carb.
    84 Ebbtide dyna trak 176 ...00 Merc XR6 150
    http://forums.iboats.com/boat-restor...ir-599150.html

  7. #7
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    Default Re: Mercury 150 XR6 hard to start!

    i will certainly change plugs. The fuel line and primer bulb from tank to motor are brand new. All the lines on inside are stock black old lines. I may replace them also and put clamps on all of it. Any specific fuel line to look for?

  8. #8
    Petty Officer 2nd Class bobkyle2's Avatar
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    Default Re: Mercury 150 XR6 hard to start!

    I just get fuel line, Since its not EFI you wont need high pressure line. NGK BU8H is the plug number you need :cheers:
    84 Ebbtide dyna trak 176 ...00 Merc XR6 150
    http://forums.iboats.com/boat-restor...ir-599150.html

  9. #9
    Seaman Apprentice
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    Default Re: Mercury 150 XR6 hard to start!

    went out yesterday after work and primed the bubble and she fired up without choking it. I think i might have been flooding it with choking before starting. You could still tell it needed some good spark tho. She was kinda sounding like she was skipping a lil bit. Real smokey when it first starts also.

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