No Spark Now? but sooty plugs before?

[Capt.Terry]

Don, I have been changing my plugs because of fouling since I bought my 1969 Irwin 31. Before when I changed the plugs the motor ran great, then the next time I run the engine one would be fouled out. clean and runs great. The plugs are not oily but the engine does smoke after the plugs start fouling. Now after the last time I "tried" to take the boat out. She ran good enough to get me out of the slip, in reverse, but when I put her in forward no power at all!! Almost like running on two cylinders, got as much speed as I could to get back in slip, put in reverse, motor died, well the next event is not pretty, thank goodness for the fender I put on the dock in the front of the slip. Anyway I put in new hotter plugs hoping they might last longer, No gas getting to cylinders, took off carb cleaned put back on, no gas to cylinders. Should not do this but poured fuel in carb. did not start. put gas in cylinders, did not start. Checked spark, no spark, but I had cleaned & set points before I first tried to start engine because after my problem with the motor and the dock, I did leave the Ignition switch on for two weeks??? The points where opened all that time. now the coil?? Thanks Capt. Terry

P.S. When I cleaned the carb the air mixture screw was only out about a half a turn?? I did adjust it to 1 1/2 turns before I tried to start the engine. also the engine did try to start when I first tried (before all the stuff I did after) but died not to hit again??

[rgoff]

You might make sure your exhaust system is not clogged up with carbon. I have problems every few years from this. When you try to rev the engine up, the back pressure causes it to die. Mine would do this in neutral after it really got clogged up.

[Capt.Terry]

thanks

Don't think that is the problem, I can clean or change the plugs and she runs like a top!!?? Only when the plugs start to foul from the soot. capt. Terry

[Don Moyer]

Capt. Terry,

The only part of your report that is easily answerable relates to your last question. If the points were in fact open when you left your ignition switch in the "On" position for two weeks, your coil should not be affected.


Beyond that observation, I can't tell from your report why your plugs are fouling. I'd start by checking the compression. Any compression over 85 psi would be OK and would not easily explain the rate at which your plugs foul, so I'd next recheck to be sure that your timing is correct. Lastly, if you're really not getting fuel to pass through your carburetor you'll have to disassemble the carburetor for cleaning.

I'm attaching a troubleshooting guide for lack of ignition. Here's a link to a guide for disassembling and cleaning your carburetor.

Don

[Capt.Terry]

Thanks

Don, Thanks for all you do for us A4 owners, I think, after owning several diesel engines in sail boats, That the A4 is a great engine. As least if you have problems, like the cars of old, you can fiddle with it and most of the time she will get you back to the slip!! thanks again, Capt. Terry

[Don Moyer]

Capt. Terry,

As per our telephone conversation today, a short check list is attached for troubleshooting for lack of spark.

Don

[Capt.Terry]

Got Spark!!, but plugs still very sooty

Don, I did all the stuff we talked about yesterday, Engine started after I found the points were not closing?? Anyway set air mixture, timing, ect. I ran the engine today for about 1 hr. got back to slip and checked plugs, very sooty. I engine smoked the whole time, blue smoke, not real bad but enough you could see it well. Engine ran top speed of 5.5 N. at 1500 rpm, all it would do. Idyled at 800 rpm doing 2 N. My boat is a 1969 Irwin 31 at around 10000 lbs and 9 foot beam. I put in a set of NKG plugs that are a hotter plug but is listed for the A4. I did put in a lot of MMO in the gas and have added about 10 gals of fuel to the tank since I bought the boat, as it had sat for 1 1/2 years. I am thinking the 2 bladed prop is to big, when I pull the boat this spring, going to put on the three bladed from Indigo.?? The engine is running very good, just the rpms are not where I think they should be. I am going to check the exhast pipe as we talked about. Also the water temp. tops out at around 125-130?? Oil 30-40. Thanks, Terry in Texas

P.S It was 71 yesterday and today out at the lake but getting back down to the 50's tomorrow.

[Don Moyer]

The Indigo prop is a good idea, but did you remember to adjust your ignition timing under power with the engine fully warmed up? This is where you slowly rotate the distributor a slight amount in each direction looking for a higher RPM.

Don

[Capt.Terry]

timing

The timing is done, what do you think about the water temp. that low. I know these are cool running engines but 125 seems to cold??? By the way the alt. is now working ?? Would a hotter thermosat make any difference in the sooting?

[Don Moyer]

Your engine would certainly benefit from a hotter operating temperature in a general way, though whether or not it will necessarily clean up your plugs will depend on whether or not something else is still affecting them. Given the difficulty of exploring some of these other things (elevated exhaust back pressure for example), raising your operating temperature to a more normal level is reasonable intermediate step.

Don

[JimG]

Exactly how much MMO did you put in the tank? Is the fuel in the tank (except for the 10 gallons) from the PO? Maybe he already had an additive in it...