mercontrol fast idle lever adjustment? 1974 150 H.P.

timmathis

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Is there a way to adjust the fast idle lever or cable? 1975 150 H.P. 1500 merc with mercontrol box. Last year it would rev good when all the way up 4000 or 5000 rpm's. After we put in a new trigger it will hardly rev to about 1200 rpm's now. Does anybody know what is wrong? It needs to rev more when cold. WOT is fine...Thanks, Tim
 

Silvertip

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Re: mercontrol fast idle lever adjustment? 1974 150 H.P.

Keep reving the engine to 4-5000 rpm in neutral and you'll be looking for more than adjustment help. There is no separate fast-idle cable. You have the throttle and shift cables. You do not adjust the cable for a fast idle problem. With the throttle lever (not fast idle lever) wide open, check the throttle plates in the carbs. They should be horizontal in the bores. If they are the cable is adjusted properly. If you engine revs to 1200 - 1500 with the fast idle lever that's plenty.
 

timmathis

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Re: mercontrol fast idle lever adjustment? 1974 150 H.P.

I know that up in smoke. My son reved it like that one time only. But now It will only increase maybe 50 rpm's it needs a little more when cold. It may only go to 850 now. It did work a lot better before. Link and sync is fine? I don't see why it don't work like before. It runs great.
 

timmathis

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Re: mercontrol fast idle lever adjustment? 1974 150 H.P.

I guess I need to take a look in the box. <br />Thanks, Tim
 

2cycle

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Re: mercontrol fast idle lever adjustment? 1974 150 H.P.

Hey Tim,<br /><br />If I'm not mistaken you can tweak the trunnion/cable/bracket setting to get more warm up RPMs. I think you may be able to undo the bracket and spin the black knob around a few times to take the play out of the warm up. Then you orientate it back into the setting and lock the bracket. It's right there where the cables come into the motor. Of course, it has been awhile. I don't think you have to go into the box to adjust and that is a pain as well.<br />Good luck, and doesn't that motor sound good at 4200 RPMs and above?
 

timmathis

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Re: mercontrol fast idle lever adjustment? 1974 150 H.P.

Thanks 2cycle,<br /> You know come to think of it my son had that cable off last year Playing with it to try to get the idle down; I will bet that is why it is not doing right. I will check it out first thing in the morning; And yes at 4200 and above it sounds like a Tiger! and will run like one to.<br />Super fast for a 150 Just love it.<br />Thanks again, Tim
 
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