1973 340 Sputtering when Accelerating
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=23731
Printed Date: October-05-2024 at 6:29pm
Topic: 1973 340 Sputtering when Accelerating
Posted By: RedandWhite73
Subject: 1973 340 Sputtering when Accelerating
Date Posted: October-03-2011 at 8:07pm
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Hey guys,
I have been reading the site for a while and this is my first post. I recently bought a 1973 Correct Craft Southwind. She had been sitting in a guys storage unit for many years and I was very happy to remove it for him. I will post a few pictures when I get time later this week. I have been having a problem and was looking for some help. The boat runs great until you get over 2200rpms, then it starts sputtering and backfiring. I replaced the points, fuel filter, fuel screen, condenser, cap, and rotor. I also made sure the timing was where it needed to be. The spark plug wires are fairly new. The boat ran a little better after I installed these parts, but will still bog and backfire at high rpms. The centrifugal advance mechanism under the cap seems to move freely, but I am unsure how to tell exactly. Any ideas would be appreciated. -Dan C. |
Replies:
Posted By: 8122pbrainard
Date Posted: October-03-2011 at 9:20pm
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Dan,
First, welcome to CCfan or at least posting. I'm sure you have found it to be the greatest CC site around.  
Since you have done the ignition related potential problems, I'd have to say go for Fuel issues. The best idea I have is to rebuild the carb. If it's never been done sine 73, it's time!! BTW, what engine is in the 73? It will help. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: RedandWhite73
Date Posted: October-03-2011 at 10:48pm
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Thanks for the reply. That seems like the logical next step. I was hoping it was one of the easy fixes. Oh well, it will be a great way to learn the carb! Its been quite a while since I've taken on of those apart.
I noticed I was getting a bit of water in the bottom. I just replaced the original plug to see if it would fix the problem. Are there any other common culprits? The bottom of the boat is in good condition. By the way it has the MOPAR 340ci engine. The boat has a great sound when wide open. |
Posted By: Luchog
Date Posted: October-03-2011 at 11:10pm
????? We need more details on this facts are not clear. >Wide open throttle should be +/-4500rpms. On the water intrusion, it could be the packing gland on the shaft or the rudder. is this your first inboard? Is it "backfiring" through the carb or the exhaust? did you check total advance or base timing only? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |
RedandWhite73 wrote:Posted By: RedandWhite73
Date Posted: October-04-2011 at 12:54pm
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When I floor the throttle it will stall out and kill. If I ease it forward and goose it a little, I can get it open wide. It will run hard all the way up to 4500 rpm, but after a few seconds it will backfire out of the carb, sputter, and stall out. If I keep the throttle anywhere over 2200 rpms it will eventually result in the same type of behavior. Anywhere below 2200 rpms and it hums along.
I only checked the timing at idle. Could that be the issue? I checked the engine compartment this morning and the plug was not the culprit of the leak. I was planning on taking the boat out this week, I just wanted to get a checklist together of everything I need to work on over the winter. Yes, this is my first inboard. What a difference! I found out reverse is a bit of a diffferent ball game from an i/o. |
Posted By: Bri892001
Date Posted: October-04-2011 at 1:25pm
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If an engine doesn't like to be "floored" from a dead stop, this is often times an issue with the accelerator pump in the Carburetor. Do you have a Holley?
But, the other problem you describe, sounds like more of a fuel flow problem... You mentioned you replaced the fuel filter. I would take a look at the anti-siphon valve, near the fuel tank. Maybe someone can confirm whether or not your boat would have one, but it comes up a lot in later boat fuel delivery issues. Another theory would be junk floating around in your carb float bowls, which would be solved by the rebuild mentioned above. |
Posted By: BuffaloBFN
Date Posted: October-09-2011 at 10:16am
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Maybe the fuel pump diaphrams dried up in storage?
Make friends with the search feature here on the site. It's a fountain of info. One thing you might have found that way is that you can run the engine from a satellite tank to diagnose the fuel system behind the engine. Put simply, run off of a small tank directly to the pump. If that solves your problem, you know where to look or to not waste your time. New to inboards...you'll luv it. Reverse is surely a different animal, but you'll get used to it. I'd also check your raw water pump impeller. It may be on its last leg if you didn't give it the once over already. Are you familiar with running it on the trailer? Inboard tip-keep a spare impeller on board. ------------- http://correctcraftfan.com/diaries/details.asp?ID=2331&sort=&pagenum=12&yrstart=1986&yrend=1990" rel="nofollow - 1988 BFN-sold "It's a Livin' Thing...What a Terrible Thing to Lose" ELO |
Posted By: Luchog
Date Posted: October-09-2011 at 3:45pm
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He probably has a webber carb on the chrysler. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |