Difficult starting on AQ130c; ideas?

[DC_Adventure]

Boat is a '73 23' Seabird with twin Aq130c's and 270T's. Fairly new boat to me. Boat has maybe been run once a year for at least the past 5 years. May have been sitting longer without operation. One engine isn't crazy about starting. It will start and run, but only after 10 different tries including pumping the gas (about 8 'pumps' with the control lever) and intermittent shots of ether. Ether will cause it to start immediately although it may not stay running. When I pull the gas line from the carbs and turn the key, gas pours out. Compression test (dry test and not warmed up) is 155, 160, 160 and 145. If I disconnect the front two spark plug wires and shoot a little ether in (with gas turned off), engine runs' 'til out of ether. Same if I switch to rear two plug wires removed. Once it is actually running on gas at idle, if I pull the spark plug wire from cylinder 1 or 2, there is a major stumble. If I pull the spark plug wire from 3 or 4, no real difference in engine smoothness. About 350 hours on very stock engine (conventional carbs, coil, distributor, etc ...). These symptoms seem somewhat anomalous to me. Any direction or ideas on how to diagnose/repair/correct? Thanks, Hans

 

[mfkadz]

When you pull a plug wire you should notice a difference. If no diff then that cylinder is not firing or not getting gas.

Seeing as it will run with ether on both banks I would say the bank with no change is not getting enough or any fuel. So, your could basically be running on one bank which would make it hard to start.

I would verify fuel to that bank, pull the carb bowl drains and see what you get. If you get some crud then you should remove, clean and replace the carbs. Rebuild kits are cheap.

mike

 

[DC_Adventure]

Thanks Mike. TBC ...

 

[DC_Adventure]

Actually, the most obvious test just hit me. To start, I am going to swap carbs from port to starboard. That should provide some quick answers. That said, I did have one symptom I forgot to mention yesterday. Once the hard-start engine is started and idling, the rear carb sounds like it is constantly sucking air. It is much noisier (in terms of air suck sounds) than the front carb. What does that mean?

 

[mfkadz]

Hmmmm, more noise. You can put a white paper a little in front of the carb and see if it's spitting fuel out the front. If so you need to check the reeds under the carb.

Also, is the 145 cylinder the one you have issues with?

mike

 

[DC_Adventure]

So I swapped the carb set over and it started much easier. Not necessarily perfect but that could just be from the replacement carb having no gas in the bowls or something. Letting it sit for the night and, tomorrow, I will try to start it again. It already starts much easier though, so that carb setup from the port engine must need a rebuild (by the way, my previous post was unclear in that I actually took the port side carb set off and placed the starboard side carb set onto the port side engine). As for the 145 cylinder, I am not sure what you are asking only since I thought I had specified those details in the first email. Maybe what I failed to clarify was that the compression readings listed were from #1 to #4. BTW, the starboard side engine, cold/dry test, reads 162, 158,162, 174 respectively.

 

[mfkadz]

Glad you have narrowed it down to the one carb.

I asked about the 145 as part of a problem thought in my head. No matter now.

mike

 

[DC_Adventure]

Thanks. As part of anticipating that rebuild, can anyone clarify as to whether this type of rebuild kit,

http://www.carburetor-parts.com/Solex-44PA1-Volvo-Penta-Marine-Carburetor-Kit_p_59.html

includes parts for an entire AQ130C with Solex carbs? What I am trying to ask is that there are two carbs per engine. So do I need two kits per engine?

Hans

 

[mfkadz]

Yes. Each kit has parts for one carb.

mike

 

[DC_Adventure]

Well today, with the swapped carb, it started immediately, so I think the basic problem is officially solved. Hans

 

[DC_Adventure]

No Title

Just to share, one of my joys in this project is the ease by which to work on these engines ... Once the engine bay cover is removed it's all right there.