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b05 T8 Wonbt IdleRun

dirtyclammer

New member
"I have an '05 Yamaha T8 f

"I have an '05 Yamaha T8 four stroke kicker that I use about 5 days a week. It ran perfect for the first few years up until this past summer. January '07 the boat went down in an ice storm and the motor was submerged for a few hours. I managed to re-build it and it ran well for over a year. Then most recently, this spring I got sugar poured in my gas tank, but the sugar seemingly never made it past the primer bulb. Stupidly, I never ran a filter on this motor for the first 2 years when it ran perfect (only the inline filter contained on the motor). I was told by 3 others who ran the same exact motor that it wasnt neccessary on this motor. Stupid, but moving on...
My problem is lately it's not been running, and/or idling at all. I've rebuilt the carbs 5 or 6 times in the past 2 months, only getting a maybe a few days at the most until the problem would re-occur. I should mention, after the second rebuild, I added a filter, and replaced the entire fuel line (new hoses, primer, connections, including factory lines, and filter on the motor).
However, I just found out the filter I added the second time was only a 40 micron filter.

Also, each time I had done a rebuild, I rebuilt the fuel pump just incase I'd find some particles in there.

Much to no avail, each time I took it apart, I never noticed any dirt whatsoever.

Now, I have read posts on here talking about the idle adjustment screw causing my problem, but I've tried that and it doesnt seem to cause any reaction to the problem.

More recently, I had someone using the wrong screwdriver to take the low speed jet out, and stripped it, so now it's stuck in the carb.
At this point, I'm thinking of trying to get it out with a screw extractor. This might be my only chance at saving this carb before I spend $400 in a new one.

I've also soaked the carb overnight twice: the first time in acetone(all I had), and the second time in carb cleaner(emptied the can).

Even after the soaks, the white oxide corrosion (from the sinking) was still left on certain cavaties of the carb that I couldnt reach with a tool. I don't think the corrosion is my problem though, because it's not anywhere visible on the inside of the carb, and because it ran well for so long just after it sank. The same also goes for the sugar; even if it had reached the carbs when I first noticed it, it ran well. So if it was a suspect, it would have caused problems around the time of the findings.

My current plan is to "hot dip" the carb one last time using one of those professional tanks at the Yamaha dealer. I'm told this method will also remove the oxide.
At the same time, I'm going to try and remove the stipped low speed jet with a screw extractor (anyone have any experience doing this?), and finally add a 10-micron racor filter in the fuel line.

I don't even know what I'm looking for.
Any comments, suggestions, hints would be appreciated!"
 
"Tony,

I have two 2003 Yama


"Tony,

I have two 2003 Yamaha T9's. When removing one of them, the carb got some salt water in it. It then sat in the shop for a couple of weeks before attention, and formed the same white oxide corrosion as you described. Including seizure of the low speed jet.

I have to clean out both carbs about every six months, to keep the motors running at peak performance. I used to disassemble and soak in mineral spirits, and lightly brush with a bronze brush, and reassemble. One of the areas that is easy to overlook are the tiny pinhole jets - someone probably knows the name - under the flat plate with the gasket. My motor is different than yours in that it is an Aussie model, but I suspect everyone is similar in having these holes. Best bet is to take a single wire strand from a wire brush and use it to clean out these small holes. Also, to clean your low speed jet, just get a can of that Gumout Carb cleaner, and use the small plastic hose that comes with it to blast away varnish. This stuff works well on cleaning the whole carb, and I usually carry a full can for when I have to disassemble a carb during a cruise. Keep it away from rubber gaskets and o-rings though, as it will destroy them.

Anyway, make sure you get these small pinholes clear. It will make the difference between a motor that barely starts, and one that runs smoothly."
 
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