1972 Merc 650. Carbs leaking and won't idle.

[steviecops]

Hi<br />I think I already know the answer to this question but I'm not very familiar with Merc engines so I want to be sure.<br /><br />I have a 1972 Merc 650 three cylider. It will start and run, but I have to keep hitting the choke to keep it running. It leaks fuel from both carbs. Alternatively, I can keep it running by squeezing the primer bulb continuosly, but fuel will flood out of the carbs while I'm doing it. When I hit the choke, the engine will rev and sounds really healthy.<br /><br />I have replaced all the fuel lines and taken the carbs off and cleaned them. I could only get gasket kits though, so I didn't replace the float needles and seats. Even after cleaning the carbs, it still needs choke or the primer squeezing and fuel still leaks from both carbs when the primer bulb is squeezed.<br /><br />I have ordered new float needles and seats. Do you think this should do the trick?<br /><br />Thanks<br />Steve

 

[AMD Rules]

Re: 1972 Merc 650. Carbs leaking and won't idle.

Might be worth checking the fuel pump as well.

 

[steviecops]

Re: 1972 Merc 650. Carbs leaking and won't idle.

I thought about that, so I removed it today to inspect it. The check valve is working correctly and the diaphram looks to be in good condition. Before I cleaned the carbs, they were leaking without pumping the primer bulb, so I assume that the pump was delivering enough fuel.<br /><br />I suppose it's worth a fuel pump repair kit to make sure though.<br /><br />Thanks<br />Steve

 

[propwash]

Re: 1972 Merc 650. Carbs leaking and won't idle.

My 68 650 had the same problem,installed new needles and seats and the leak was gone and no more choking to get her running,quite a job to get the carbs off,but a lot cheaper than a shop,also had to take her out after and readjust the idle in forward gear,runs like a dream machine now.<br /><br /> PROPWASH.

 

[steviecops]

Re: 1972 Merc 650. Carbs leaking and won't idle.

Great news propwash.<br /><br />I know all about how much trouble it is to get the carbs off! I just wish I'd installed new needles and seats the first time I had them off. Still, you live and learn ;o)<br /><br />Thanks for the info.<br />Steve