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wadeallen

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"Still on the 73' Mercury

"Still on the 73' Mercury 9.8 outboard thunderbolt ig. I cleaned the carb and put it back on, the carb looked real clean. I made sure the fuel was running to the carb, tried pull starting it in neutral with choke and without, and nothing. I put it in forward gear and full throttle, it fired and ran sounding good for about four seconds and then died and wouldn't fire back up. Please help."
 
"Pull the plugs and see if the

"Pull the plugs and see if they're wet (and check for spark while they're out). If the plus are wet, you might have a perforated fuel pump diaphragm.

Jeff"
 
"wade again I pulled the plugs

"wade again I pulled the plugs the top one was wet the bottom dry,The plugs have fire still wont start in the start position"
 
"This might sound odd, pour so

"This might sound odd, pour some 2 cycle oil down the carb, wait a minute and try and start. If the oil seal is bad on the botoom this might get it going for a bit"
 
"I put the 2-cycle oil in, tip

"I put the 2-cycle oil in, tipped the motor back to let it drip back into the carb, let it set for two min It is starting a little easier (on the first pull), but it is still only starting in forward gear with the throttle in full blast. Won't start at all in neutral, will idle down a little from full throttle but not much and will run now in full throttle without dying. Please continue your help."
 
"The oil trick is a tempory fi

"The oil trick is a tempory fix, it suggests that the lower seal is bad. I would pour some more down the carb, wait an hour and remove the lower unit. Any fresh oil on the shaft or drips would confirm its a bad seal needing repair. I don;t understand why it wouldn't start in neutral unless it doesn't have spark in neutral. Putting it in gear advances the timing which should make it harder to start.
Perhaps Jeff will voice his opinion on this old timer.
With the plugs removed, spin the engine over. Does each cyl go poof?"
 
"Perhaps the reason it will st

"Perhaps the reason it will start in drive is because the throttle will go full throttle, in neutral the throttle won't go all the way up, it has a stopping device so it's only in idle or a little above idle in the neutral position. Both cylinders have a vacuum and a exhale when pulling the rope. I sincerely thank you for your advice, I'll put the oil in the carborator tomorrow, check the lower unit shaft, and get back with you."
 
"Your sure the carb is clean,

"Your sure the carb is clean, you can blow air through the main jet and air into the idle ports behind the carb butterfly plate. Is there fuel in the float bowl after it runs then dies?"
 
"I blew air through the carb,

"I blew air through the carb, everything seems to flow clearly, the inside of the carb looked spotless and shiny. The way they got the carb put in on the front of the motor, you can't get to the float bowl without taking the carb off of the motor. I put some more 2 cycle oil into the front of the carb and have let it set. Hoping it will lubricate the seals, maybe they are dry. How much adjustment is on the needle valve on the carb, the one with the spring, how much do I turn it out? Is it one and a quarter?"
 
"I took the carb off, took the

"I took the carb off, took the brass screw off the bottom, took the needle valve with the spring out, and blew air through all the holes, air seemed to go through well, there was gas in the bowl, but put it back together, hooked the fuel back up and can't get it to fire even in full throttle now. ????????????????????????????"
 
"There is a clear little hose

"There is a clear little hose on the left side of the motor that has some oil in it, it hooks to a fitting on the top and bottom of the side of the motor about the middle do you know what that would be?"
 
That hose allows oil from the

That hose allows oil from the bottom of the crankcase to be circulated back to the top bearing.
 
"The hose was plugged, i took

"The hose was plugged, i took it off, and cleaned it out, pulled the rope until I saw a little oil coming out the bottom, put the hose back on, pulled on the choke, put it back in full throttle and it started third pull, would stay running even throttling up and down with throttle in higher positions. When I took it back to start, it died. I truely appreciate all of your help as that I am a poor man and really don't have the money to take it to the shop. Thank God for people that know."
 
"is this your carb or the one

"is this your carb or the one above
http://www.crowleymarine.com/mercury_parts/458/70.cfm
this one has the fuel pump built into the carb, if you blew into the needle, thats the float and needle, you sent air the wrong way. I don't know what damage it would cause but its not the main jet.
If someone put the carb to engine gasket on backwards the fuel pump won't work.

Did you pump the fuel bulb to re-prime the carb, sorry need to ask. So, which carb...."
 
"The picture on that page look

"The picture on that page looks just like my carb. Also, after cleaning the carb and putting it back together and priming it with the bulb it started in full throttle idled back down almost to the neutral position and then will throttle back up to full blast, it just won't start in neutral, but made great progress"
 
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