mercruiser wont idle

[king474]

ok i got a mcm 260 with a quadrajet 4bb that will idle for about 5-10 mins then sputter and lose rpm then die it will idle at 1000 rpm and i cant get it any lower trying to get it to 650-700 that the manual says to have it at. just rebuilt the carb to see if it would help but didnt change athing also missing the petcocks on the exhaust manifolds that are shown on the manual on page 7a-22 but have a feeling they have nothing to do with my problem. any help would be great

 

[cr2k]

Re: mercruiser wont idle

How are your points and condenser? Most carburetor problems are electrical in nature. (ign sys)

 

[king474]

Re: mercruiser wont idle

havent looked there but ill give it a try tomarrow and let u know thanks

 

[king474]

Re: mercruiser wont idle

To update I just now got around to checking out the ing system took the coil off to test it out and found out some how it got full of water so I'll replace it sometime this week and hope that's all it was

 

[Gary H NC]

Re: mercruiser wont idle

If the points and condensor have not been changed and a full tune up with timing and dwell set then that would be the starting point.

It would help to post the year,serial numbers,ect. so we know what ignition system you have.

 

[Bifflefan]

Re: mercruiser wont idle

Could also have a vacum leak.
Are you adjusting the idle with the throttle cable on or off the carb?