1976 Merc 150 hp idles to high....

[ole evinrude]

just bought this motor for my 13' checkmate, and got everything on the motor ready to go now, it idles at a constant rpm, but it just to high. rpm's to high to shift into gear.

is this as simple as adjusting the little brass 'barrel' on the throttle cable? would that change it so when your just sitting there running in neutral it would idle at a lower rpm?

this is the biggest outboard i've ever worked on, with 3 carbs, and don't have a manual jsut yet. i figure since all 3 carbs run off a linkage between them, there's got to be an idle adjustment somewhere prior to the carbs.

any ideas?

Thanks

p.s. the picture shows a merc 110hp, but i decided to bump it up a bit more.

 

[diaric]

Re: 1976 Merc 150 hp idles to high....

wowser, now thats a motor, lol. looks about as big as the boat, might run a little deep in the water.look on the left side of the motor above where the throttle cable feeds in. you should see a idle stop screw. if you can't get it to idle down enough, then disconnect cable and adjust length a bit so it will have a little more travel to idle down.

 

[Scaaty]

Re: 1976 Merc 150 hp idles to high....

Looks like fun..could be a handful though, so watch it (been there, done that, and now a built 135 on a 16 foot flatbottom).
Now, anyway, dont mess with anything but this, or ya screw up the link and sync. Don't touch the carbs. The idle screw will be in front, top, on the right looking at the motor. It work against the distributer. Back it off and see what happens. If nothing, you need to disconnect the throttle cable at the lever and the clip that holds the 2 cables. This a two person job now. Have someone start the motor, while you apply pressure toward the rear at the bottom of the throttle lever, putting pressure against the idle stop screw. See what it does now.
(DON"T LET THAT PUPPY GET AWAY FROM YOU OR YOU WILL GRENADE IT)
Adjust as needed (very little). NOW, set up the throttle cable barrel nut so that when you hook up the throttle again (important)...its applys slight pressure to hold the whole mess tight against the idle screw. If it runs fine, leave it alone. And in the throttle and shift nuts (1/4-28 NyLoks), back off a 1/4 to 1/2 turn..they need a little slack to rotate slightly. I would make sure you are set at NO MORE than 21 degrees timing, and run 89 Mid Grade gas.
And now that I think of it, a different motor huh?. Bet the cables were off.. Just do the cable thing I described first..bet that cures it

 

[OldMercsRule]

Re: 1976 Merc 150 hp idles to high....

Wow, that is gonna fly!! I would see if the anti cavitation plate is even with or up to i" higher then the lowest point of the bottom of the boat. As another said: it looks plenty deep in the water to me too. I would wear a life jacket n' hang onto yer left one. Take it up easy. I had a 1250 short shaft on a 14' Carlson tunnel that looked almost as scarry as that combination does. IT ACTUALLY WAS REAL SCARRY 0-70+ MPH in a very short space. Tunnels do not chine walk as semi v(s) do, but they will grab too much air from time to time and endo on ya, (which usually kills ya). Good luck and be carefull. What's the hull rated for? The Carlson was supposed to have no more then 85hp, (until the Coast Guard tag misteriously dissappered), just is case my kids had to collect on me life insurance!!! JR