my 1972 18 hp evinrude

I

irod

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i feel i got everything working right carb is clean points are set right new plugs and wires but it won't idle oh and it will run better with choke on all the way i feel i got a vacum leak but i got the gasket sealed up good for the carb and it pops alot if i try to get to idle with out choke what should i do
 
samo_ott

samo_ott

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Re: my 1972 18 hp evinrude

If it runs better with the choke on it's a carb issue. It is not getting enough fuel in it's regular running condition. Take it apart and make sure every passage is clean. Did you put a new carb kit on it? Did you take the high speed jet out and clean behind it?
 
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F_R

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Re: my 1972 18 hp evinrude

Agreed, assuming you actually have fuel in the carb, it is plugged up. (Remove the drain plug to verify that there is fuel in there). I'll lay you odds that the high speed orfice plug is gummed up. It is deep in the hole behind the drain plug and requires a special screwdriver to get it out. It has a precision sized hole in it and will simply not tolerate any modification, including gum or dirt.
 
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R.Johnson

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Re: my 1972 18 hp evinrude

You do have the float in, upside right?, I've run into that a couple of times.
 
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irod

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Re: my 1972 18 hp evinrude

i have took the carb apart and made sure everything is clean with carb cleaner and using a aircompresser using the carb spray i made sure all the gallerys are open to i think i forgot to put in my message each piston average about 70lb compression so i am stumped
 
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F_R

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Re: my 1972 18 hp evinrude

OK, after re-reading the original problem, let's re-visit this thing. Is the problem only at slow idle speed? Will it run fast without the choke?

If this is true, then did you put a new "bearing" in the hole where the idle needle goes? Do you even know there is a "bearing" in there? Actually, it is a plastic funnel shaped seal that keeps from sucking air in through the needle threads. Comes with a carb kit.

Did you remove the core plug from the top of the carb body and check for dirt in the tiny holes beneath it?

Lastly, it is possible that the lower crankshaft seal has broken or fallen off, admiting air into the case. Powerhead removal is required to find out.
 
samo_ott

samo_ott

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Re: my 1972 18 hp evinrude

70 psi is low but it should still run. Once you get it going you should try a decarb.
 
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irod

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Re: my 1972 18 hp evinrude

thanks for ur reply the carb is fully clean but i have no idea what u mean about bearing in carb

F_R said:
OK, after re-reading the original problem, let's re-visit this thing. Is the problem only at slow idle speed? Will it run fast without the choke?

If this is true, then did you put a new "bearing" in the hole where the idle needle goes? Do you even know there is a "bearing" in there? Actually, it is a plastic funnel shaped seal that keeps from sucking air in through the needle threads. Comes with a carb kit.

Did you remove the core plug from the top of the carb body and check for dirt in the tiny holes beneath it?

Lastly, it is possible that the lower crankshaft seal has broken or fallen off, admiting air into the case. Powerhead removal is required to find out.
Click to expand...
 
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F_R

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Re: my 1972 18 hp evinrude

Look at the parts list for your motor. You will see the slow speed needle, a retainer which is for friction, and the bearing part number 314166. The bearing is way deep in the hole and you can't even see it, but it is in there. I made myself a hook tool to get it out, but some people use a drywall screw -- I haven't tried that method. Once you get the old one out, simply push the new one in with a suitable rod or punch.

If you don't have a parts list there is one at http://shop.evinrude.com/
 
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