Re: What is a sneeze ?
(per manual for 1986 150)
Throttle Valve Synchronization
[NOTE]With the engine idling in Neutral, if loosening the carburetor lever adjustment screws results in a better idle, improper synchronization of the throttle valves is indicated.
At Idle, all throttle valves in each carburetor must be completely closed. If the linkage between carburetors is misadjusted so that one carburetor has the throttle plates slightly open , it will result in poor quality idle.
1 - Remove the air silencer cover to observe the throttle valve action.
2 - loosen the throttle cam follower screw, Push the throttle cam follower away fro mthe throttle cam. The throttle cam follower must not touch the throttle cam during this procedure.
3- loosen uper and lower carburetor lever adjusting screws (D) [CLF - the book shows three cam looking things on the starboard side of each carb, they point to the upper and lower] which allows th ereturn springs on the throttle shafts to fully close the throttle vales.
4 - Partially open the throttle shafts and allow them to snap closed to be certain the throttle vales are closed. Press downward on tabs of the adjusting links to remove backlash.[CLF -the book shows a picture of a dude pushing down on the cams to be sure they vales are closed whilst tightening the screw that was loosend] Tighten the adjusting screws. Adjust the lower carburetor linkage first, then the upper linkage. Move the camm follower and check that all throttle shafts start to rotate at the same time.
Cam follower Pickup Adjustment
1 - Connect a throttleshaft amplifier (E) to the top carburetor throttle shaft, as shown. [CLF - it looks like an aligator clip with a rod/wire sticking straight up, it appears to be clamped onto the upper carburetor shaft, at the cam]
2 - While advancing the throttle cam, the short embossed mark (F) [CLF in the picture it looks like there is a larger cam that is just above the middle carb's cam, the mark should be on the larger cam] on the cam should align with the center of the cam follower (G)[CLF it looks like the cam follower is on the middle carb's cam] as tip of the amplifier begins to move.
3 - With the follower screw loose, align the short embossed mark on the throttle cam with cent of the cam follower. With the throttle vales in the closed position, hold the cam follower against the cam short embossed mark and tighten the cam follower screw.
Cam Follower Pickup Timing
1 - connect a timing light to No1 cylinder spark plug high tension lead.
2 - Advance the throttle by moving the throttle control lever until tip of the amplifier [CLF alligator clip with wire]. Remove the amplifier but do not move the throttle control lever.
[NOTE] On some models, the idle stop adjustment screw may be advanced until center of roller alligns with first mark on cam. AFTER TIMING IS CHECKED, RETURN IDLE STOP ADJUSTMENT SCREW TO ORIGINAL POSITION.
3 - Start the enigne and observer spark advance with timing light. The proper spark advance is listed below.
Throttle Pickup Timing
150 Hp, 175HP 7degrees plus/minus 1 degree BTDC
4 - To adjust the pickup timiing, lossen the jam nut. Rotate the top of the thum wheel toward the crankcase to increase the pickup timing degress and away from the crankcase to decrease the pickup timing degress. [can't tell from the picute what the hell they are talking about it looks like it is above the idle stop screw]
5 - Tighten the jam nut and and repeat steps 1 thru 4. [not sure why they state repeat here???]
Wide Open Throttle Stop Adjustment
1 - with the engine NOT running, manually advance the throttle lever to the wide open position. [CLF looks like an idle stop screw but near the bottom of that same lever that the idle stop screw is attached]
2 - adjust the wide open stop screw (A) [looks like so that the roll pins in the carburetor shafts are vertical. Roll pins must not go past vertical.[CLF no clue what roll pins they are talking about but they are on the carb's shafts]
Maximum Spark Advanced Adjustment
[CLF If you want to mess with that you'll need a test wheel, PM if you really want that info, I'm guess you haven't palyed with the WOT max advance screw]
Some info though
HP Degrees
150 32 plus/minus 1 BTDC
150ST 30 plus/minus 1 BTDC
155, 175 28 plus/minus 1 BTDC
[CLF -I give you this in case your butterflies are cracked open thus letting more air in, and thus idle air bleeds are not metering air properly.]
