Lean Squeeze. Please Help

[amarcil77]

I have a 73 johnson 85 hp. When I try starting the motor it takes 5 starts to get it running. After I get it running I have to continuously bump the choke. Once I get the revs up a little more than idle it is fine. It will propel my boat to 25 mph and run great. Once I bring it back to an idle after about a minute I have to start bumping the choke again. This issue is a real headache when trying to launch and dock the boat because it is always stalling. Any suggestions. Thank you

 

[Tim Frank]

Clean the carbs

 

[emdsapmgr]

Agree. Possible that the idle passages in the upper carb bodys are restricted with dried fuel. That will cause a lean condition, resolved by frequently choking it. This will be a complete carb teardown, some special carb cleaner and carb kits. Pull all the jets out for cleaning and visual inspection.

 

[amarcil77]

I will pull them and try cleaning. This all started after I rebuilt them. I must have dislodged some crap and pushed it somewhere else

 

[Tim Frank]

You can also check fuel filter and make sure that fuel lines are not deteriorated.

 

[F_R]

Trouble started after rebuilding the carbs? That should raise concern. How about the throttle linkage? Both butterfly plates closing completely? Link & sync? Are the screw-plugs in the front of the carburetors tight? (They are NOT adjustment screws). Was it running ok before you messed with it?

 

[amarcil77]

I did set all the linkages. The choke and throttle plates are opening and closing all the way. Before the carb rebuild. It barely ran. It would run on the hose but wouldn't run while submerged. I also have what I think is excessive fuel consumption. I am going thru 11 gallons of fuel pretty quick. If I had to put a mileage on it I would say I am getting about 4 miles to the tank. And my WOT speed is about 25 mph according to gps. It's on a 16 ft bayliner.

 

[Tim Frank]

4 miles per tank? That's nuts.
Must be a major fuel leak.
Did you own this boat from new, and are these new problems or has this boat had issues since you got it 2nd hand?

 

[amarcil77]

I picked the boat in the fall. When I bought the owner told me it needed $1800. Worth of work. What I had found was good compression and a timing advance that was locked up by the goo from a exploded stator. Not knowing anything else I rebuilt the carbs and changed the impeller. Now this is what issues I'm having. I think I'm going to buy 2 carbs from eBay rebuild them and go from there.

 

[Bosunsmate]

what do your plus look like?
I think you should rule out other issues before buying new carbs

 

[amarcil77]

Sorry I thought I replied yesterday. Plugs are normal they have 3 outings on them about 5 hours

 

[amarcil77]

I went to pull the carbs off and clean them. I found two issues. Could this be the cause to my idle issues. I found the silencer to carb gasket was missing a good size chunk missing also the small tube on the back of the silencer that runs to the lower part of the block has a 2 inch split in it. I'm going to the store to buy these parts. I hope this is the fix. Also I read about a decarb. Would that help, I have no idea if it has ever been done. Thank you

 

[racerone]

Check for a torn fuel pump diaphragm.

 

[emdsapmgr]

Good that you resolved the two airbox issues, but it's unlikely they contribute to your running issues.

 

[Tim Frank]

Not knowing anything else I rebuilt the carbs

Any chance you could take the time to give us an accurate history since you picked up the boat last fall?
You say you rebuilt the carbs and water pump....water pump is a no-brainer, but did you do the carbs for giggles, or because of symptoms....i.e. did you run it before doingg the carbs? If so, what was the indication to do the carbs?

Do you have an OEM manual yet?