A-4 Engine Racing

[Phil]

I just bought a 1982 C27 with A-4 engine last winter and put it in the water for the first time yesterday. It's my first boat! The engine came to life on the second try after 18 months of being on the hard.As I was testing the engine on the stands, and after using it in the water, it seems that I can only keep the engine from racing at the minimum throttle by using the choke. At minimum throttle and nearly full choke, it does about 5 knots. The RPMs are directly related to the choke position, and it seems to run smoothly at various choke settings.Question: What's wrong? If something's wrong, should this be fixed? I'm shopping for water skis.Phil DeckerS/V "Catmandu"

 

[Brian Ranniger]

Adjustments

The carb is pretty basic on the A-4. You should check the idle speed adjuster screw...actually, first disconnect the throttle cable from the carb, then start the engine making sure the throttle doesn't go wide open. I don't think the carb has a return spring for the butterfly valve. If it idles OK then you need to adjust the linkage to the lever in the cockpit. If the engine still wants to race you might have a vacuum leak (big one) some where. You can check for vacuum leaks by spraying starting fluid where it might be leaking. If the engine bogs down, there's your leak. Be careful to ventilate the area though. Don't want to blow up. I'll bet the first thing is the problem though. You can also check moyermarine.com for their FAQ section. Most of these things have already been asked and answered. Good luck.

 

[Garry @ S/V TASHTEGO]

Throttle Cable

The end of the throttle cable sheath at the back of the throttle lever in the port cockpit locker is held into its base by a little brass clip which is easy to displace when loading the locker. Check to see that it has not come adrift. It happened to me once and after I reconnected it I added a nylon cable tie to make sure that it won't come adrift again. Because there is no throttle return spring, the throttle will no longer respond to movements of the throttle lever if the cable sheath comes adrift. If it comes loose with the throttle full on it will stay that way as moving the throttle lever just raises and lowers the cable and sheath together. Scary in the long channel into TASHTEGO's marina!

 

[Rob Rich]

Hey Phil,,,

Congratulations on owning a fantastic boat and a fantastic engine. I have a 79 C-27 with the Atomic, too.Go to sailnet and subscribe to the A-4 mailing list. There a a bunch of A-4 freaks on that list, and you will learn quick. You can also post your question and get about 10 replies in two days, often from actual marine mechanics.Good Luck, and enjoy your new toy!Rob

 

[Phil Decker]

Problem solved!

I took all of your advice. I found the carb and checked it for leaks, adjusted the idle, and checked the throttle cable. Nothing fixed the problem. When I had the throttle cable disconnected, I noticed that I could move the throttle lever closed with my finger, and then it idled normally. When connected, the cable was just far enough out of alignment to prevent the throttle from going all the way to closed. The distance is a small fraction of an inch. I unwound the fine adjustments a little on each end of the cable, and tighted the lock nuts (which were both loose). I then re-attached the throttle cable. Purrs like a cat now.Thanks!PhilS/V Catmandu