225 Yamaha Boggs in Mid range

Bradster941

Petty Officer 1st Class
Joined
Mar 4, 2003
Messages
203
Today at the ramp I came across this elderly gent having problems with his 12 yr. old, looper Yamaha 225. Testing while on the trailer, it started and idled ok, idled well in gear as well. <br />But advancing through the mid range and beyond under load, it would die out.<br />At first I thought the V-6 was dropping a cylinder or two so I ran home and grabbed my tools and a hose with muffs.<br />On dry land I pulled spark plug wires with my grabbers and checked all cylinders for spark – O.K.<br /><br />Pulled each plug to check for lean conditions, -O.K.<br />Sensor on side of carbs for advance, ( I assume ) checked O.K. according to owner. ( a ½ volt on up)<br />He had just rebuilt the carbs and possibly insert the ports backwards, ( left and right), so we switch those around just for grins.<br />Still same result.<br /><br />So, we have Spark, we have Fuel, but under load, it immediately dies through the mid range.<br />I noticed a pick up sensor on the starboard side of the fly wheel and wonder if this was for the electronic advance. <br />Assuming no fuel problem, then wouldn’t the inrush of gas with no advance cause it to choke out like that?<br />Or is there something I’m missing here?<br /> :) :confused: :)
 
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