Rebuilt Carb Won't Adjust-"Fixed"

jayhawkokie

Petty Officer 3rd Class
Joined
Mar 21, 2008
Messages
92
I just rebuilt the 3 carburetors on my 1987 90 Hp Merc. They looked clean when I pulled them, but I went ahead and soaked them in carb cleaner snd sprayed them with Chemtool and blew out all the passages with compressed air.

I put them back on the engine and ran the engine on the hose muff to make preliminary adjustments before taking it to the lake for final adjustment. The top carb won't do anything when I turn the idle air adjustment screw. I can turn it down all the way into the seat and back it way out and the rpm doesn't change.

What did I do wrong? I didn't touch the jet under the screw with the red sealer.

I'm thinking I should have left them alone. I purchased the boat from my Uncle, it had been 2 years since it ran. He said it ran fine before he quit using itn but I was told by a couple of "experts" that since it had been setting I should pull the carbs.

Jayhwakokie
Grand Lake O the Cherokees, Oklahoma
 

hkeiner

Lieutenant Junior Grade
Joined
Oct 17, 2006
Messages
1,055
Re: Rebuilt Carb Won't Adjust

Re: Rebuilt Carb Won't Adjust

I would confirm that the compression is OK and that the spark is OK on the cylinder that is fed by the carb in question. A bad spark or bad compression would cause the symptoms you describe. Next, I would try spraying some 50:1 fuel mix into the carb throat to see if the motor responds. If it does, then I would conclude that you have a carb problem, such as the float is adjusted wrong or there is an obstruction in a carb passage. Just my thoughts...
 

bullbat

Petty Officer 2nd Class
Joined
Mar 10, 2009
Messages
152
Re: Rebuilt Carb Won't Adjust

Re: Rebuilt Carb Won't Adjust

i agree check spark and compression on top 2 cylinders and if good u may have the float stuck or trash in the main jet
 

jayhawkokie

Petty Officer 3rd Class
Joined
Mar 21, 2008
Messages
92
Re: Rebuilt Carb Won't Adjust

Re: Rebuilt Carb Won't Adjust

I broke down and took the boat to a good Merc mechanic here in town. I will post the results when I find out what his diagnosis is.

The Crappie are biting and I'm wanting to go fishing.

Jayhawkokie
 

jayhawkokie

Petty Officer 3rd Class
Joined
Mar 21, 2008
Messages
92
Re: Rebuilt Carb Won't Adjust-"Fixed"

I got my boat back from the mechanic yesterday, he did a complete Link & Sync and put a can of Seafoam in the tank and ran it for a while, let it set and ran it again, that seemed to fix it. I guess I didn't quite get all the crap blowed out of the one carb. I plan to keep a close watch on it for a while.

I took it out on the lake and it has a hole shot reminicant of my 1966 GTO Convertible I used to own. It performed flawlessly for almost an hour running at different speeds.

Gone Fishing
Jayhawkokie
Grand lake O' the Cherokees, OK
 
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