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I just recently bought a motor from a fellow ifisher, and it had been sitting for a while. I started it up just fine, however it won't idle down without dying. I suspect the carb needs some work from sitting for a few years. I called a local shop to see what they would charge to get it done and they quoted me 200.00 just to clean it. That's more than half of what I paid for it.
It's a 90 merc, 8 horse...
Was wondering if anyone has any suggestions of how I can get it done cheaper or if it is something that I can do myself. I've never had a kicker before so my experience in this area is limited...
thanks!!
 

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First, this is probably not recommended by any manufacturer, but it seems to have worked for me with a few gasoliine engines.

To clean the carburator without taking it apart. Buy some carburator/fuel injection cleaner gasoline additive and add it to the gasoline at much greater than regular strength. I've used as much as 1 pint for 1 gallon of gasoline. Run it for a while at higher speed to cycle the cleaner through the engine. It may take 30-45 minutes or more to start working.

Of course, you may also want to change the plugs and make sure you are using new fresh gas with the correct mixture.
 

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It might just need a bit of adjustment - did you try turning the idle screw a half turn either way?

You can do it yourself, but maybe that's not necessary. New plugs, fresh gas - take it out and run it some.

I removed and overhauled the carbs on my antique Merc last winter, amazingly enough it still runs! Your local library should have some do-it-yourself manuals.
 

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If you don't have a manual, try to find one. I've had trouble on my 89 8-horse Merc with the screw loosening. The trick is to tighten it all the way, then back it off 1 1/2 turns (per the manual). From there, make very tiny adjustments, but remember, the motor isn't warm, so you should let it fully warm up at whatever speed works before fine tuning it.

The one thing you hope you don't find is a "grooved jet", which can happen from running the motor too lean. The symptom for that is that the motor will start with starter fluid, but won't with the choke.

[ 07-09-2003, 04:59 PM: Message edited by: Pete ]
 

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Good advice on the carb adjustment. Don't adjust the screws more than 1/8 turn at a time.
There really isn't much to those little carbs. They're pretty easy to strip and clean.
 

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If the motor runs ok with power but wont idle down without dying you might give this a try before spending money on a carb job.

Disclaimer: some of the terms used here may not be correct as I am not a certified outboard mechanic

Its possible you just have a bit of dirt or grit stuck in the needle n seat. To correct this in the past I have used this method to cure the problem.

With the engine cover removed start the motor and keep it reved up so it stays running. ( if it has the all in one throttle and shift controls in the tiller like mine then you can throttle it up with the lever by the carb with it in neutral)

With the motor revved way up take something ( small piece of cardboard, paper,etc.) and cover the air intake on the carb until it almost chokes itself out then remove it. Do this 3 or 4 times then repeat the process with the adjustment screw ( its the needle and seat I THINK) run all the way in. Next back it way out and repeat the process again. Sometimes this will suck the obstruction out.

Once this process is complete then run the adjustment screw all the way in, then back it out the 1 1/2 turns the owners manual calls for and start the engine. Then its just a matter of fine tuning it like posted earlier.

Its worked for me on my 8 hp merc before and also on my 15.

If you cant figure out what the heck I'm talking about drop me an email and I'll give you my phone # so maybe I can do a better job of explaining it.

Hope it fixes your problem and saves you some money
 
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