Lead shot in my 86 25hp evinrude carburetor

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F_R

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They generally are used to plug a hole where a passage was drilled. Most likely yes in this case an idle passage.
 
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mayorj1227

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F_R said:
They generally are used to plug a hole where a passage was drilled. Most likely yes in this case an idle passage.
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Cold start idles great till it warms up, then start shaking like flooding out. Rebuilt carb. Ck plugs, 1 good burn the other black
 
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F_R

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Don't have an answer for that, but think about it. Plugs seem to indicate one cylinder running richer than the other one. The carburetor feeds both cylinders equally. Have you considered a leaky fuel pump diaphragm? That would flood one cylinder.
 
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mayorj1227

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F_R said:
Don't have an answer for that, but think about it. Plugs seem to indicate one cylinder running richer than the other one. The carburetor feeds both cylinders equally. Have you considered a leaky fuel pump diaphragm? That would flood one cylinder.
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Thanks I'll ck that, that's the cylinder that's running rich that operates the pump
 
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racerone

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Does spark jump a gap of 3/8" ( 1 cm ) on both leads ?----Yes a leaking diaphragm is common.----New diaphragm are easy to get / make .----Easy to install.
 
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mayorj1227

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racerone said:
Does spark jump a gap of 3/8" ( 1 cm ) on both leads ?----Yes a leaking diaphragm is common.----New diaphragm are easy to get / make .----Easy to install.
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Took pump off, notice the hole that feed vacuum to pump was wet
 
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racerone

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The pump operates with PRESSURE pulses not vacuum.-----And there is fuel in the crankcase so you might see some moisture there.-----Does spark jump a gap of 3/8" on both leads ?-----Does your primer PUMP on the hose go hard ?
 
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mayorj1227

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Runs great up on power band, just can't get it to idle hit and missing on one cylinder
 
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racerone

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Does spark jump jump a gap of 3/8" on a test device , yes or no ?-----It will help just you to answer this simple question !----Is the thermostat installed and working properly ?
 
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Crosbyman

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the rear pulse hole of the pump exposes the diaphragm to the fuel-oil mixture routed to the cylinder ports so it is normal to see it " wet "

the inner surface is of course handling the fuel and pushes it to the carb with check valving ...so both surface are ...wet

the important issue here is that fuel does not feed from the pump inside to the outside...(motor side vacum port) causing flooding or increasing the fuel oil mix to be pushed in the matching cyl. and causing a rich mixture.

look for pin holes in the rear diaphragm if you wish (dare) to open the pump you have


pump should only pass air in to out never out to in
 
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Crosbyman

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mayorj1227 said:
What kind of test device
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put 2 gyproc srcews on a wood board 3/8 inch appart (top rims) ...easy as pie :)

wire one to the engine block wire the other to the plug boot clip
see if the spark jumps across. :)

report back !!
 
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F_R

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mayorj1227 said:
Took pump off, notice the hole that feed vacuum to pump was wet
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Easy to check. With pump off and hoses still attached, give the squeezer bulb a squeeze. Fuel should not squirt out the pulse hole. If it does, diaphragm is shot.
 
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mayorj1227

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F_R said:
Easy to check. With pump off and hoses still attached, give the squeezer bulb a squeeze. Fuel should not squirt out the pulse hole. If it does, diaphragm is shot.
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Thanks guys for y'alls help. Problem solved. 2 of 3 pinholes for low speed and idle plugged up. Purrs like kitten now. Thanks again
 
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