Smokin' A-4

[Melody Miller]

Hi Guys and Gals:My Atomic 4 is smokin' occassionally and I can't figure the reason.The engine temp and oil pressure (at start- up - 35) seems O.K. The smoke comes out of the exhaust. The only thing I'm a little unsure of is the oil level. I'ts very hard to read the stick since the oil is clean and almost transparent on the stick.One time it occurred soon after I started the engine and the second time after motoring for about 30 minutes. Anyone have any ideas?Thanks,Melody

 

[Ray]

Over full on oil can make a very smokey mess.

If you have bad oil control rings on the pistons the motor would smoke all the time. If you have bad valve guides the motor will smoke upon start up. I don't know if the atomic 4 is over head valve or not. If it is a flat head then valve guides are not the problem.Gas dulution of the crankcase oil from very, very excessive fuel use or leakage in the carb into the intake manifold can also cause oil burning and is a very explosive condition. I advise you accuratly determine your oil level first off as all other causes are secondary to the overfull problem. Ray

 

[Larry]

Smokin' A-bomb

Melody; Have you done a compression test to check the rings and valves? You may need a top-end job, which can be done with the engine in place. To see your oil level better, wipe the stick, apply masking tape to it, re-insert and check the reading. Good luck.Larry W.

 

[Rob Rich]

Idling

Hi Melody, Enjoy reading your posts on the A-4, they are right on the money.I have noticed that my A-4 will smoke after it has been idling (barely turning) for 3 or four minutes. The reason is that it runs slightly under-temp, and low rpms cause a slight build up of carbon and MMO. When you crank up the rpms again, the accumulated gunk burns under the higher pressure/temperature, and the result is greyish smoke which goes away in a few seconds. Are you using Marvel Mystery Oil in your fuel, like Don Moyer suggests? He recommends putting enough of this into the gas to cause a trace of smoke in the exhaust from time to time. This is also what causes my engine to smoke at higher rpms after idling for a while.Is there anything that seems to preceed or occurr along with the smoke, like high load, headwinds, topping off the fuel tank, long periods of inactivity, etc..? There is a great e-mail list full of A-4 motorheads at sailnet. You can sign up on their list, ask your question, and get some great responses. A couple of the guys are actual marine mechanics.Good Luck, and keep us posted.Rob

 

[Melody Miller]

A-OK

Hi Larry, Rob, and Ray:Thanks for all the input fellas. I motored about 1 hour today and after 30 minutes I noticed smoke which disappeared after about 5 minutes. No problems thereafter.I used to put MMO in my car all the time until I read that it might interfere with other additives. I do not use in my boat, but I will start if that's what the A-4 guru says.I'm going to conclude that some gunk was just burning off and things are O.K. I generally do not run my motor very hard and maybe there's some build up somewhere that burns off when I power up.I will try the masking tape idea to better read my oil level.Thanks again,Melody Millers/v Spice of Life

 

[Rob Rich]

For More info on engine oil....

I am going to write a post on engine oil analysis tonight under Ask All Sailors. It has to do with companies that analyze engine oil and can tell what is going on with your engine by analyzing its oil chemically...You might want to check into this. I am going to do it just for peice of mind.Rob