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1982 mercury 25hp wont ldle

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66tray

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I have a 25 hp mec . The outboard wont idle I have to turn enricher all the way down to start.when back off the enricher it start to sputter and back fires though the carb. I have change the spark plugs,check compression ,(120 psi for both) took off carb clean and put back on . I just cant figure this out Thanks
 
Ok i ll will give that a try. i did ajust idle mix screw It made no difference .when i do get it to half way idle and give it gas it starts missing and shaking then back fires though the carb, And i smell gas the whole time.
 
If you are getting a backfire/blowback through the carb it sounds like you have a busted/stuck open reed.

At least this one has the reeds right behind the carb.

I would suggest you pull the carb off and the plate located directly behind it then take a look at the reed petals and look for a chip, missing petal etc.

If you shine a flashlight into the intake and can see through to the crankcase that's a bad thing...
 
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I just check out the reeds i have a chip in one. Now could that cause it to backfire and not run correct??


And thanks i never even thought about that
 
Absolutely. The reeds are what stops the crankcase pressure from escaping (keeps it in the crankcase until the piston moves below the intake port and then forces it into the cylinder.

A broken reed will let all/most/part of the gas/oil/air mixture destined for one of the cylinders to blow out through the throat of the carb.

So at best you are running on 1 1/2 cylinders...
 
Yeah that is what it sounded like when i running the engine. Thanks i could not figure what was wrong it I am going to change them out and keep you posted what happens. Thanks Agian Tracy
 
Okay i have replaced the reeds rebuild the carb but no new float. And it still wont idle. I even tryed to advance the timing. Dont know what to do know does anybody have any idea ???? Thanks
 
I dont think i have the wires wrong one? would it back fire ?? I just went and pulled the #2 plug wire while it was runing and it didnt die ?? I did notice it had gas sitting in the carb while i was trying to start it. Would that be the float ???
 
I did rebuild the fuel pump and this morning i did adjust the float 1/4 and check the primer bulb which was good, holds pressure. I put all it back and runs almost the same . I took idle needle and turned all the way down then 1 1/2 turn out and tried to smooth out idle didnt work. Then i tried carb cleaner to spray around looking for leaks ( not in carb) . could not find any leaks . I did notice that one of the needles was seeping. Would this cause it not to idle, Or would be out of time because i messed with it ? Thanks
 
Is this " no idle condition " something that happened suddenly ??------Is this something that slowly got worse ?------How long have you owned it ?
 
i got the engine like this . Thought it was just the carb but the reeds were bad and repaced them. It idles now but not good it has a miss and still smell like gas like it not burning it. I did replace spark plug and check coils
 
Cover the pulse rubber tubes and the tubes out of the engine for operating your carburator pump and run your engine with the hand pump.
 
I finally got the engine to idle and i found carb leaking from the (needle?) in the front of main jet ?? Any help to to try to fix. Thanks
 
How is it leaking? Is fuel dripping to the outside of the carb? The idle screw threads are self sealing. Remove the screw for inspection but count the number of turns it takes to remove it so you can reinstall it to the right setting. Inspect the carb bowl at the screw's theads for a crack.
 
I was going to replaced the float and needle seat and found out they dont make it anymore. Nobody has one. Does anybody know what carb will interchange with an 1982 25hp mercury or what i should do ????

Thanks
 
i did try seaway marine nothing. So i called a mercury in east cost. he said that the needle can fit off a husqvarna chain saw here is the no#RK-23-HS thats in case someone else has this problem. but it has no float
I thank eveyone for helping me. I will update as soon as i get the part to see if it fits
Thanks
 
Try these guys - www.twincityoutboards.com - go to their "contact us" and tell them what you are after - they may have a whole carb or be able to tell you what else might fit.

You have an old Tillotson and yes, parts are getting scarce. The Walbro's that replaced it do not look like they can bolt right on in it's place. I you end up really stuck we can try and see if the mount will match something else, even if it means a bit of jury-riggin'
 
Just called twincityoutboards. They have 18hp carb for $ 350.00 and nothing else . I dont wont to spend 350.00. on this engine . do you know what carb would come closes to this

Thanks
 
Float needles are a fairly common item.---------Visit a shop with your old needle and a $5.00 bill between your fingers.-----They will match it up with something that works.
 
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