[JFNStuart]

Dear All, Following a previous post regarding the lack of power on this engine (S/No. 5731713) at WOT, does anybody know how the throttle linkage on the engine should perform.I asked previously about the low RPM I had found when trying the engine for the first time. It runs and revs fine in neutral, but does not develop power when run in forward. People suggested that it might be the spark plugs not firing on all cylinders or the carbs gummed up or the fuel pump/lines.Before I start stripping the carbs or fuel pump I would like to check what the proper arrangement of the twist grip throttle linkage should be.I had another look at the engine tonight and discovered that although the twist grip advanced the throttle, when I looked at the actual movement of the throttle lever on the carb, the throttle lever did not advance more than about half of its travel potential. I do not know if this is correct but it would seem to me that the twist grip linkage is only advancing the throttle about 50% of the possible travel. The linkage has an adjustment screw which is set almost to its minimum, however, I do not want to mess with this until I find out just where it should be set at. Would this upset the idle speed?It reminds me of revving a car engine manually at the carb rather than using the accelerator.Does anybody know or have a diagram of how the throttle linkage should be set. The seloc manual is useless!I am going to check the plugs, fuel system and clean the carbs over the weekend but if anybody can tell me how the linkage should operate I would be very grateful as I may end up stripping a carb or fuel pump that do not need any attention. Best regardsStuart

[eurolarva]

Just guessing here but when you have the throttle wide open the throttle shutter on the carb should be wide open or at 90 degrees to the carb. You do not want the shutter to advance beyond wide open.

[sonar4]

On most of my outboards, the throttle would only go part way in neutral. This is a good precautionary measure to prevent launching engine internals caused by eratic harmonics from no-load on the engine. Motors with oil pumps dampen this harmonic potential with oil pressure. Two strokes = no oil pump to crankshaft bearings. I'd say, check your throttle movement with the shift in forward and wide open (engine off) and see what you have. If you get 3/4 towards full, good enough for long life. A mechanical guess on your issue would be a vacuum leak, intake blockage moving forward or maybe float level in carb. Hard to tell without being there...