Chrysler 140 losing power. All comments appreciated

[texman]

I have a Chrysler 140 that is losing power. Shop worked on it explaining to me that it needed both carburetors overhauled as well as new fuel pumps. This work totaled around $400. The boat ran fine for about 1.5 hours. The second day out it ran for about 15 minutes at about 75% throttle, 28mph and then suddenly slowed to about 10mph. Brought it back to the shop. The mechanic calls me after about 3 days and informed me that it needed an ignition overhaul. He said it was "dropping 3 cylinders". He said there is only one place in the U.S. that does this procedure. The cost $350. My question is:
Would this problem be caused by carburetors and fuel pumps? After the overhaul of these components, could the problem continue because of the ignition system? Was the carburetor/fuel pump un-necessary? What is the defect that would cause the boat to not plane out at 75% throttle?

[Guest625101138]

Ignition problems this severe can be usually assessed easily by looking at the plugs. If they are wet, oily or carboned up then it is probably ignition. If they are dry and lighter colored then it is probably a fuel deficiency. So ask to see the plugs so you can assess which one is still firing. I doubt that it would idle on one cyclinder. If it idles OK then misses as it loads up then this is more likely a fuel issue.

If the fuel system was cleaned once and it worked OK then maybe it has been fouled again. I know of an instance where a tank liner started to peel and repeatedly starved the fuel supply. I know of water being in the fuel and causing large loss of power. Do you have an in-line fuel filter? Check if it has water or rubbish in it.

If you have had a fuel supply problem then it can cause overheating in the cyclinders and they burn out but this is more progressive failure mode.

You should ask the service shop how they concluded that the ignition has a problem. I do not know the configuation of the Chrysler ignition but it is most likely a separate coil per plug. Hard to work out how three plugs could be affected at the same time. You should ask for a demonstration to see what plugs aren't sparking. Have the mechanic explain the ignition system to you. There is a web site selling the coils for USD45. (I know the questions can be a pain for the mechanic but it is your money he wants to keep spending)

I would be surprised if there was only one place in the USA that can service the ignition system.

Rick W.

[Frosty]

Sure it was'nt overheating?