merc 650 kills in idle/shallow setting?

[bill cook]

72 merc 650 thunderbolt runs great wide open, 3/4 1/2 throttle idles ok for a minute or two, then dies have to choke to get started again. also any ideas for a shallow water setting? I am running in a river with a 15' fglass trihull and need to get the motor tilted occasionally

 

[jim dozier]

Re: merc 650 kills in idle/shallow setting?

I believe from your description that you are running too lean on your idle circuits. Not only should it not die but you should not have to choke it to restart it when warm. You have either:<br />1. Idle mixture screw set inappropriately lean, open 1/4 turn<br />2. Gummy deposits in your idle circuit blocking fuel flow, probably requires carb rebuild.<br />3. You have an air leak somewhere.<br />4. You have all or some of the above.

 

[sharkcat]

Re: merc 650 kills in idle/shallow setting?

Sounds like you need to:<br />Buy or borrow a manual,Remove & dismantle carbs,<br /> Clean them,Set float levels,Install them,set the timing/sychronization,Adjust idle mixture.You will need gaskets as the old ones will probably be no good.<br />Probably not what you want to hear but its the only way to know you are not trying to fix something like a blocked carbie by adjusting the idle screw.<br />Theres never enough time to do the job properly..But theres always enough time TO FIX IT!!!<br />You can fit power trim & tilt to this engine.Ive done it on a 1971 650 I think the unit came from an 850.If you go this way make sure you get the bolts tht attach the rams to the centre section & bracket as they were hard to track down in stainless...Good Luck