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  1. #1
    Alan Thomas's Avatar
    Alan Thomas Guest

    Default " My engine starts fine when c

    " My engine starts fine when cold. Then it idles rough and stalls. When hot ,sometimes it it won't start. Any help? "

  2. #2
    Join Date
    Feb 2001
    Location
    Central West Florida
    Posts
    11,708

    Default "Alan.... You don't say wh

    "Alan.... You don't say what year that 120hp is, something that we should know. However, first things first, check the compression on all cylinders. Then check the spark (with the spark plugs out). The spark should jump a 7/16" gap on all cylinders. Let us know what readings you get.

    Has the engine been sitting for any length of time? Can you hear the Primer Solenoid (choke) click in when you press the ignition key in? What do the spark plugs look like, and what kind are they? What charging system does you engine have (low/regular amps or 35amp)?

    Joe[img][/img]"
    Our questions require answers. If you refuse to answer our questions, how can we answer yours?

  3. #3
    Alan Thomas's Avatar
    Alan Thomas Guest

    Default The engine is a 1987. Compres

    The engine is a 1987. Compression is fairly equal on all cyl. 105 to 115.
    Engine was stored over winter and winterized.
    Choke solenoid is working properly. New L77JC4's just put in after winterizing was run out. Not sure which charing system this engine has but don't think it is the 35 Amp.
    Have not checked the spark gap on plugs out of engine.
    Alan

  4. #4
    Join Date
    Feb 2001
    Location
    Central West Florida
    Posts
    11,708

    Default "Alan.... It would be a good i

    "Alan.... It would be a good idea to check the compression again, making a note of what cylinder has what reading. A 10 psi difference between cylinders could be the start of something unpleasant. The spark check (s/plugs must be removed) is also important. If the spark doesn't jump a 7/16" gap on all cylinders at cranking speed, that would indicate a problem with the ignition. Keep in mind that a carburetor(s), even though a engine was winterized, could be fouled (it happens).

    Even though your engine has a low amp charging system, it is possible that the stator assy (under the flywheel) which is the beginning of the ignition system, is cracked, and leaking a substance out of its coils which would affect the ignition. Usually when that happens, the ignition may be fine when cold, but as the engine warms up, especially in the flywheel area, the stator encounters a voltage drop, and power to the pack drops off resulting in faulty ignition.

    Joe[img][/img]"
    Our questions require answers. If you refuse to answer our questions, how can we answer yours?

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