2007 Yamaha 50TLR on Alumnacraft 16 1/2 engine problems

I purchased this boat and engine from cabelas last April (2008) and used it only four times before having it winterized last November. When I went to use the boat this spring I noticed that it started fine but when I moved it from neutral to forward the engine would die. If I let it just move forward slowly for about 2-3 minutes it would eventually start to gain power and i would not have any problem while at higher speed until i would either slow down or stop. I'm new to boating and just guessed that it had to due with the winterizing of the engine. So I changed the gas, oil and plugs and just used the boat last week again and had the same problem. The boat has around 10 hours max of use. It seems that other people are having similar issues with this engine and year (2007) . One last thing , if I put the boat it reverse, it run fine and never stalls.. Any ideas or suggesting would be very much appreciated !!

[99yam40]

My guess is old gas fouled carbs or what ever your fuel system you have. Did you winterize with fuel stableizer and fog the motor?

The boat was winterized for me at a service shop, so I don't really know what they used. But why would the boat run fine in reverse and once it is going at full speed? If the the Carbs were fouled would this still be possible?

[boats.net]

Low speed circuit in carb probably plugged, remove and clean carbs.

Does the low speed circuit only control forward speed and not reverse?

[cranebug]

I have a 96 50TLRU and had similar problems. It was the idle circuits. I never tried reverse but would believe it because you don't have the same "load" conditions as the prop in forward. I took that bank of 4 carbs off 4 times to "blow and clean" out and it still didn't work (as well as full rebuilds). I was told by my local YAMI spe******t that I needed new carbs to the tune of $1800. For 35 bucks I bought a can of Gunk carb cleaner, totally stripped the carbs down, and soaked 1 at time. The first two carbs; nothing noted. Upon dunking the number three, fine threads of %$$%^& were noted disolving into the Gunk. Put the bank back together; and while running more additives than gas (ring free and seafoam) I have not had any problems in two yrs. (please note there may be debates as to whether it is safe to dunk the carb bodies in GUnk but I was desparate) no ill effects. And hey, my local Yami said I needed new carbs. NOT!! The bottom line is that todays gas SUCKS. It would be fine if we were able to run our boats everyday Good luck

Thanks to everyone for your responses !!