Twin 4.3 mercs with alpha ones throttle issue

[Tcorrell02]

Just bought a used boat, 99 Larson 290 cabrio with twin 4.3s with alpha ones. Starboard idles about 1000 rpm and seems to go right into gear and almost immediate throttle response with lite movement of control. Port idles around 5-600 and SEEMS to go into gear immediately but throttle moves considerably before responding. The throttle issue made me concentrate on it more than gear engagement. I have had boats before but never twins. Shift cable adjustment? Should also say starboard cable new last year, port original as far as I know.

 

[QBhoy]

Your port one is closer to what it should be than the starboard.
does the starboard not seem very harsh going into gear ?
Are the idle speeds you say when at idle in gear or in neutral ?
there is normally a bit of travel in the lever to go into gear from neutral really. A positive and swift enough movement is what’s required. Any slower and it’s likely not too good for the wee alpha. They are simple things with only a dog clutch tooth to tooth engagement

 

[alldodge]

Agree, port is good and starboard needs adjusting.

What is the engine serial number and is it a EFI or MPI?

 

[Tcorrell02]

Your port one is closer to what it should be than the starboard.
does the starboard not seem very harsh going into gear ?
Are the idle speeds you say when at idle in gear or in neutral ?
there is normally a bit of travel in the lever to go into gear from neutral really. A positive and swift enough movement is what’s required. Any slower and it’s likely not too good for the wee alpha. They are simple things with only a dog clutch tooth to tooth engagement

Starboard does seem a little harsh/clunky. Port is actually hard to tell when it engages. Idle Rpm's are in neutral. I have always tried to be easy on shifting when backing into a slip. At wot the starboard lever has to be backed off, I'm guessing an inch plus to synchronize the Rpm's.

 

[QBhoy]

Starboard does seem a little harsh/clunky. Port is actually hard to tell when it engages. Idle Rpm's are in neutral. I have always tried to be easy on shifting when backing into a slip. At wot the starboard lever has to be backed off, I'm guessing an inch plus to synchronize the Rpm's.

Either you need to adjust your idle speed (when warmed up and under way, checking it’s ok when in nuetral after) or you may be drawing air somewhere.