Won't run in idle. Help.

[mrt214]

Oh yeah Ok guys put on your thinking caps. I cannot get either engine to stay running in neutral unless the rpm is over 1600. Neither engine will idle. I have changed all filters twice and tore starboard carburetor apart and found very little dirt changed needle valves,float all good, idle mixture screw changed, put back together and no change. When I disengage gear lever and start motors they run until I pull back to neutral and they stall. They do start in neutral but won't stay running. Any suggestions. HELP. Oh yeah bravoii s with 350. 1996 3200scr.

[Phillbo]

Take the gas cap off and see if that makes a difference.

[mmwjr]

Did they both start doing this at the same time? Was it shortly after refueling? Remove the fuel filters and pour into glass jars, let settle and look for water.

[mrt214]

Yeah did all that. Even took both fuel lines off tank and put them directly into 5 gal has can. Still no idle. Took off gas cap, cleaned vent hose. I'm starting to believe it may be the linkage somehow.

[mmwjr]

When were they last tuned up? I have heard folks having a similar issue due to a bad distributor cap and rotor. In some of these case these were even new but defective.

[Vroom_vroom]

Lots of “fuel issues” are ignition related when it comes to engines. Read your plugs as well.


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[mrt214]

I'm going to replace wires cap plugs and see what happens. I only have another month or so left before boat comes out.

[Phillbo]

I doubt both engines would have the same electrical failure at the same time. the cause has to be something that is common to both engines....

[mmwjr]

Originally Posted by Phillbo

I doubt both engines would have the same electrical failure at the same time. the cause has to be something that is common to both engines....

My thoughts as well but he did not answer my question asking if they started acting up at the same time. However doesn’t sound like they have been tuned up in some time so no harm

[mrt214]

Sorry I didn't make it clear but yes they both konked out the same day. I did make it back on one engine (port side) with no power steering of course. This all happened when I went to 4500 rpm and one stalled and then the other. This is why I started with fuel issues. Some how I still think it a fuel related problem.

[mmwjr]

Originally Posted by mrt214

Sorry I didn't make it clear but yes they both konked out the same day. I did make it back on one engine (port side) with no power steering of course. This all happened when I went to 4500 rpm and one stalled and then the other. This is why I started with fuel issues. Some how I still think it a fuel related problem.

Does both engines draw from the same fuel tank?

[mrt214]

yes 1 tank 186gallons 3/4 full.

[mmwjr]

Originally Posted by mrt214

yes 1 tank 186gallons 3/4 full.

Did you refuel recently? Sure seems to be the only common item between them. When you ran on an external tank did you first change fuel filters? Water/crude may have hitting into carb bowls so an external tank would not help until carbs are cleaned and new fuel filters. You may need to have the onboard fuel scrubbed.

[mrt214]

I added 40 gallon of 93 octane after problem started. all filters have been changed 3 times. Carb was taken apart and cleaned before running from separate tank. No different.

[mrt214]

Well I finally got my answer yesterday. I pulled the carb off the starboard engine and took it completely apart. I used a welding tip cleaner in every hole and cleaned every orifice in it. The only thing I could not change was the accelerator pump. Wrong pump. Put it back together ( no parts left over) fired it up and bingo. Runs like it's supposed to. I'm guessing something was trapped in there. Anyway now I'm working on port carb. Halleluiah I get to take the boat out for the winter without towing it. Thanks to all for all suggestions and believe me I tried all of them

[mmwjr]

Glad you resolved the issue, thanks for posting your findings.

[Phillbo]

Thanks for the update. Any idea where the sludge in the carbs came from?

What type of fuel tank do you have?

[mrt214]

186gal single tank. I must have stirred up the bottom when going up on plane. I pulled both pickup tubes and measured the length against the tank and the tubes were long enough to lay on the bottom. I cut the tubes so they are an inch off the bottom. oh yeah aluminum tank.