1974 mercruiser 120 carb issue

[kjmacke]

Hello all here is my problem. The idle cam on the carb seems to flip over from time to time. When this happens and I throttle the boat back to idle the engine will die due to the difference in idle travel with the cam flipped over. What is causing the cam to flip over and how do I fix it. Thanks Kelly

 

[Fishermark]

Your picture is not coming through. Is this a Mercarb or Rochester? I recently rebuilt my Mercarb and took some pictures. (Always handy when it comes time to put it back together! ). Here's some pics I took which may help make sure yours is correct. (Assuming it is a similar carb).

 

[kjmacke]

Thanks fishermark for your help. The carb has not been rebuilt it has a problem that I described in my post. The cam keeps flipping over while I am driving the boat. This affects the idle since there is no cam to rest on. I flip the cam back over and everything is good for awhile until it flips back the wrong way again. Whats up????

 

[Fishermark]

Is this a "new to you" boat? How long has it been doing this? I cannot imagine this problem simply coming out of nowhere. You mention the carb has not been rebuilt. Does that mean ever? If it has ever been rebuilt there is no guarantee that it was put back together correctly. Just saying...