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  1. #1

    GP 1200r wont start after week of storage&will start with dropping fuel into cylinder

    Hi all ; ive got a
    GP 1200r wont start after week of storage & will start with dropping fuel into cylinders and will run & start fine all day- bring it home flush etc.. then store and repeat process.

    I recently bought it and owner said he had got the carb done but don't think there is much truth in that.

    Any advise?

    Last edited by mozzy; 12-02-2013 at 11:18 PM.

  2. #2

    Join Date
    Jan 2006
    Texas City, Texas
    Your problem is not uncommon. If you have the stock carburetion system still in place, you have the accellerator pump and the choke to help you start.

    The accellerator pump acts as a primer when starting: pull the throttle as many as ten times to inject fuel into 2 of the 3 carbs (prime). Usually you only have to pull the trigger 3 or 4 times. You should be able to hear fuel squirting into the carbs when you are in a very quiet environment (like a garage).

    You also choke the carbs 100% and then crank.

    Once it starts, do not over rev, just stop chokeing it.

    Sometimes it is hard to pull fuel from the tank after the boat has been down for a long time. These Mikuni carbs do not have bowels for fuel storage like in 4 strokes, and sometimes the fuel seems to evaporate from the carbs. You are just chargeing the whole fuel system back up.

    If you ever begin to have trouble starting the engine after an hour or two being down, then I suggest that you have someone look at your carbs.

  3. #3
    thanks salty- so pull throttle first a number of times and then choke it? in that order or does it matter?

  4. #4
    I started a thread about this a little while ago, but since it was end-of-season noone really had the chance to fully test this out. One caution to you though is; you must have already done the oSide carb dill mod with a 95 restrictor jet on the return line, and you really need a pressure gauge to monitor things. DO NOT do this if you have not yet drilled your carb return passages - I wouldnt trust a previous owners word on this either. For you, it may be an interesting read and something to get your mod/bug going.

    Fuel regulator in-line return

  5. #5

    Join Date
    Jan 2006
    Texas City, Texas
    Quote Originally Posted by mozzy View Post
    thanks salty- so pull throttle first a number of times and then choke it? in that order or does it matter?
    It doesn't matter.

    When you pull the throttle, whatever fuel that is still in the carbs is squirted into #1 & #3 cylinders. To choke it is like putting your hand over the carb intake. When you crank the engine, the pistons each go down and the negative pressure created to pull air into the cylinder also pulls in fuel from the fuel line through the carbs and into the crankase..

    Just remember to put the choke back or else the engine will run rich. There is also such a thing as chokeing it to much. If you try to crank it for a long time without it getting started, and then you start to smell a strong gasoline smell, then you flooded the engine. You then just crank it with no choke and no throttle. Most people do not run into this problem very often, but it can happen. All you have to do is get one of the three cylinders to fire off, and eventually the other two will come around.

    Once again, I am assumeing that you are running with a stock engine and no aftermarket primer.

  6. #6
    hey salty, ZeroClient & green hulk ive been away the last few weeks but back to this tread;

    as I recently bought it I don't know what mods the previous owner has done ; is there anyway of telling what mods have been done to the carb?

    that way it may become clearer why it wont start without manually dropping petrol in cylinder!??

    also salty I notice u mentioned carb squirted into #1 & #3 cylinders- that's a help as ive just been dropping it into #2 & #3 but still work but good info!

    ive tried trigger 3 or 4 times then choke as recommended above with no luck!

    thanks for all the help - Moz

  7. #7
    Out of all my skis, my GP1200r is the most difficult to start. SUCKS.

    Verify your battery is good.
    Try full choke, crank for 15 seconds max at a time, pump the throttle while cranking, rest for 30 seconds, and repeat. It should go after 2~3 times of doing this.

    To the link I posted above, it sounded like I possibly stabbed a decent solution - only the winter season everyones hibernating and only one person tried it out (With what seemed like great success).

  8. #8
    Thanks ZeroClient

    So in simple terms what is the oSide carb dill mod and how is it done? ; I assume drilling / opening up carb to allow more fuel/air mixture.

    Which in result increased performance but lowered the fuel pressure / fuel ran back to tank when is stopped?

    did you install a fuel pressure regulator & is there any way of telling if the above mod as been done besides that it wont start afer been sitting for a while

    thanks for the info

  9. #9
    Yamaha xl1200 Xlt1200 Gp1200r Gpr Xlt Xl 1200...

    Lexington 40504, KY, United States - 1 month ago on
    For sale $495
    ...listing is for a full set of carbs removed from a running freshwater 2001 Yamaha gp1200R. These carbs have been upgraded with the oside bill upgrades including: No accelerator pumpt-handle adjusters for the high and low jetschokes have been removed and smoothedjet in the return lineallen bolts on the diaphram and pump coversplumbed for a primer for cold starts ...

  10. #10
    this guys got a primer for cold starts???

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