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  1. #1

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    97 GP1200 won't fire unless manually primed

    Hey guys, I've been researching threads for weeks and have thoroughly enjoyed the reading. My 97 GP1200 won't crank unless I remove the carb cover caps and pour a little gas in each. Once that's done, it will fire all weekend. If it sits a few days, this must be done again. Fuel pump losing prime? Does this ski have a pump like my 96raider1100? Can't seem to find right thread that helps me. Thanks guys.
    Newbie poster, but scanning threads for months. Hard to put computer down!!! The thirst for knowledge is addictive. Martin


  2. #2
    Yamaha artisan Cutlass's Avatar
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    All three carbs have a fuel pump built in. Is your dad's machine 100% stock or has anything been modified? Typically you can pull the choke closed and crank the starter for a few seconds (maybe a couple times) and the fuel will start flowing in the carbs. If it doesn't that that means maybe the pulse signal is weak (ie cracked/leaking pulse hose or low compression), the fuel pump diaphragm is bad, or the check valve discs in the carbs are creased.
    Most people just install a primer kit. That'll make these things start right up.


  3. #3

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    Quote Originally Posted by Cutlass View Post
    All three carbs have a fuel pump built in. Is your dad's machine 100% stock or has anything been modified? Typically you can pull the choke closed and crank the starter for a few seconds (maybe a couple times) and the fuel will start flowing in the carbs. If it doesn't that that means maybe the pulse signal is weak (ie cracked/leaking pulse hose or low compression), the fuel pump diaphragm is bad, or the check valve discs in the carbs are creased.
    Most people just install a primer kit. That'll make these things start right up.

    Thx cutlass, I will try a couple of times as suggested and then install primer kit anyway.

  4. #4
    Yamaha artisan Cutlass's Avatar
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    Be aware that the instructions that come with most primer kits are incorrect. They want you to tee into the "ON" fuel line, but doing it that way causes a restriction in the fuel system. The tee restricts fuel to the carbs and can cause the engine to run lean...and destroy itself.
    The better way to do it is to install the tee into the return line after the carbs. But by putting it into the return line, that can cause you to have to pump the primer a whole bunch times (if the fuel lines are empty, like 1st time each season or after a carb rebuild.) In that case you have to crank the engine for little bit to get fuel into the return hose. Usually it works just great during the season though. To have it operate better you can buy a longer length of return hose and make a big low hanging loop so there is always plenty of gas in the return line for the primer to work. Mine works pretty good so far without having to do that.
    The other method that work really well is to run the reserve line straight from the tank to the carbs, and use the "on" hose for the primer and bypass the on/reserve/off switch completely.

  5. #5

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    Quote Originally Posted by Cutlass View Post
    Be aware that the instructions that come with most primer kits are incorrect. They want you to tee into the "ON" fuel line, but doing it that way causes a restriction in the fuel system. The tee restricts fuel to the carbs and can cause the engine to run lean...and destroy itself.
    The better way to do it is to install the tee into the return line after the carbs. But by putting it into the return line, that can cause you to have to pump the primer a whole bunch times (if the fuel lines are empty, like 1st time each season or after a carb rebuild.) In that case you have to crank the engine for little bit to get fuel into the return hose. Usually it works just great during the season though. To have it operate better you can buy a longer length of return hose and make a big low hanging loop so there is always plenty of gas in the return line for the primer to work. Mine works pretty good so far without having to do that.
    The other method that work really well is to run the reserve line straight from the tank to the carbs, and use the "on" hose for the primer and bypass the on/reserve/off switch completely.
    Thanks for info, I believe I like the bypassing on/off/reserve switch idea. I appreciate you taking the time to offer that information.

  6. #6
    Resident Coffee Addict Oshawapilot's Avatar
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    FWIW, I know that this is a common GP1200 problem...and I suffered it for a while - but I discovered that during the initial cold start in addition to full choke holding the throttle wide open results in a successfull start after only a few seconds of cranking - the wide open throttle seems to be the trick, as before I used to be like everyone else and crank until the battery was nearly dead before it'd start...if it did - lots of times I ended up doing the "pour gas in the carbs" routine as well.

    Now, full choke, full throttle, crank...and away she goes. Gotta get the choke off RIGHT away (the second it starts) using this method though as otherwise it floods quickly.

  7. #7
    Yamaha artisan Cutlass's Avatar
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    Yep that used to work for me also. I don't remember if I was doing WOT but I was definitely squeezing the throttle (with full choke) to get mine to cold start. I believe its even suggested to do so in the owners manual

  8. #8
    Resident Coffee Addict Oshawapilot's Avatar
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    I just go WOT. As soon as I hear the faintest hint of a fire I let off the throttle and it usually roars to life immediately afterwards without revving up excessively or anything.

    I always cold-start on the trailer as well before even getting near the water - I'll only let it run for about 5 seconds or so, but it's enough time to get everything primed and a touch of heat on the cylinders so that when I'm in the water the next startup is dead easy...and away I go. I also avoid being "that guy" who clogs up the launch with a vessel that won't start, only discovered AFTER launching.

    It works like a charm for me - I don't feel any need (personally) for a primer kit myself anymore.

  9. #9

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    Quote Originally Posted by Oshawapilot View Post
    I just go WOT. As soon as I hear the faintest hint of a fire I let off the throttle and it usually roars to life immediately afterwards without revving up excessively or anything.

    I always cold-start on the trailer as well before even getting near the water - I'll only let it run for about 5 seconds or so, but it's enough time to get everything primed and a touch of heat on the cylinders so that when I'm in the water the next startup is dead easy...and away I go. I also avoid being "that guy" who clogs up the launch with a vessel that won't start, only discovered AFTER launching.

    It works like a charm for me - I don't feel any need (personally) for a primer kit myself anymore.

    Thx guys, I will try all of that before makin any changes

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