Hello this is my first posting and I hope someone can help me out. I have a 1975 230.6 with a M180 engine in a 114 chassis. Yes this is a gray market car. It has the dual zenith carb setup. I have rebuilt the carbs and put on a new fuel pump. Prior to installing the new parts I had a gradual loss of power. Now the car will not idle or run unless I advance the ignition timing to 50+ degrees? My first thought is that perhaps the chain has jumped a cog or two. I should also mention that the car has about 80,000 miles on it and it has been converted to an electronic ignition via Allison. I look forward to any help.

Try disconnecting the throttle linkage to each carb and see if the power is the same, both times.

One aspect often missed on the Zenith carb is the diaphram that pulls off the secondaries.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I appreciate your reply. I did replace the diaphrams during the rebuild. It spits back through both carbs and is very rough. It's hard to get it to run enough to tell anything. I thought that maybe it had jumped time(chain) and by advancing the ignition timing so much that it some how is compensating. Is there any markings on the camshaft to help check alignment? I look forward to your reply.

There is a "V" notch in the washer behind the cam gear and a cast pointer on the first cam support.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician