stalls in fwd or rev Idle

niknik57

Cadet
Joined
May 31, 2004
Messages
8
Im having a problem with stalling on my right engine. I have twin 1996 yam 200 hps. I cleaned the carbs and reinstalled twice for the same problem. Much better the second time around. Now the engine stalls in fwd or rev idle only. I notice after a good run when im back at the marina and trying to dock the boat, my right eng will drop to 500 rpm then slightly below, cough then stall. My idle in neutral is 750. Ive changed the spark plugs, fuel filters, removed fuel pumps and checked for fuel out of hole in back for diaphram problems, my squeeze balls are less the a year old, fuel screens on engines are new. The only thing i did see, when I had the carbs apart, the bowl gaskets on 2 carbs were rubber and the other 1 was paper. I dont see where that should make a difference but who knows. the yamaha dealer told me the the fuel air mixture should be 1-1/8 on both sides instead of 1-1/8 and 5/8. is that so? Ive set them at 1-1/8 and 5/8. carb link adj. was also done. thanks for your help.
 

Ray Neudecker

Lieutenant Commander
Joined
May 25, 2004
Messages
1,656
Re: stalls in fwd or rev Idle

If you did not replace the bowl gaskets, they could be coming apart and undoing your cleaning. You will see the fine steel threads in the gaskets many times when this is the problem. The dealer is likely closer to right with the air adjustments.
 

Arnold96

Petty Officer 3rd Class
Joined
Jul 29, 2002
Messages
75
Re: stalls in fwd or rev Idle

Are they both supplied off of the same fuel connection to the tank? Where does the fuel supply split?
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: stalls in fwd or rev Idle

the cough and die tells me something is causing the intake mixture to go lean. thus the cough. its actually a backfire but the reeds contain it.<br /> do the cxarbs again. pay closer attention to the idle fuel and idle air circuits. the mix screws do not alter the ratio of air to fuel, just how much of the ratio can pass the needle<br /> good luck and keep posting
 

Osprey

Petty Officer 2nd Class
Joined
Jun 19, 2004
Messages
128
Re: stalls in fwd or rev Idle

I am currently working on a 1995 175 with the same issue. Just purchased engine had not been run in a couple years. Taking it in this week to have carbs gone through. I'll let you know how it goes and what is done.
 

niknik57

Cadet
Joined
May 31, 2004
Messages
8
Re: stalls in fwd or rev Idle

I did not redo to carbs, but I opened the fuel air mixture a little more (1/8 of a turn). I ran the boat all day. In and out of fwd and rev idle and it only coughed twice all day but never stalled, so I think Im on the right track...any thoughts....thanks...nick
 
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