93 Sunsetter hard to start but runs perfectly

[nbeihl]

I just picked a 1993 Sunsetter and it has a difficult time starting. In order to start it when it is cold, you have to run the starter for at least 20 to 30 seconds. Pumping the throttle seems to have little effect on how fast it starts. Once it starts, it runs and idles perfectly. It even idles perfectly cold. If the engine has been running, it will start up instantly. If the engine has been off for 15 min or so and I try to start it again, it takes 20 to 30 seconds of the starter even though the block is warm. Another symptom that may or may not be related is that sometimes when the engine is warm and I just got done with a ski run and I shut off the motor, it will continue to run for a few seconds... (my Dad calls it "dieseling") If I let the engine idle for a min or so, it will shut right off rather than running rough for a few seconds on it's own. Once the engine is started, the boat runs perfectly and idles perfectly all day. The guy I got the boat from thinks that the engine is running lean??? Any suggestions? I think this has something to do with the carb settings….

[rugger]

I would adjust the timing first. It's easy to do but requires a timing light. Dieseling is usually a timing issue. You should be to find appropriate settings in your manual... or ask a parts store about timing a motor like yours. (or tweak it in both directions a LITTLE. I haven't had my coffee yet so I can't think right now if dieseling means the timing is too advanced or retarded). After that... see how it runs before you mess with the carb. Timing will also help effect if it runs lean or rich. If it's the carb, check the auto choke, etc., clean it, etc. the actual lean/rich mixture setting is just a simple screw in most cases. You probably have a quadrajet carb (a good one), and not too difficult to adjust.

[martinarcher]

I would adjust the timing first. It's easy to do but requires a timing light. Dieseling is usually a timing issue. You should be to find appropriate settings in your manual... or ask a parts store about timing a motor like yours. (or tweak it in both directions a LITTLE. I haven't had my coffee yet so I can't think right now if dieseling means the timing is too advanced or retarded). After that... see how it runs before you mess with the carb. Timing will also help effect if it runs lean or rich. If it's the carb, check the auto choke, etc., clean it, etc. the actual lean/rich mixture setting is just a simple screw in most cases. You probably have a quadrajet carb (a good one), and not too difficult to adjust.

rugger is right on. I'm betting your timing is just a bit too retarded. This would explain the hard starts as well as the dieseling. If the timing is to retarted, the plug fires a little late and causes a bit of excessive heat in the combustion chamber. When you shut it off theres enough heat buildup in the chamber to cause the mixture to fire without actual spark from the plug. Sounds like it cools enough if you let it idle first to prevent the ignition without spark.

Get yourself a timing light or borrow one. It is super easy to check timing on the 350's. Just go very easy when rotating the distributor. You don't need to move it much to make a difference and if you boat is running goos i isn't too far out. Who knows you might a get a bump in your fuel economy too!

[nbeihl]

Thanks for all of the great info. Now that I think about it, changing the timing makes perfect sense. It has been a few years since I timed an engine and I was doing it with someone who had a little more experience.

Do you know about what the setting should be for this particular engine? I do not have a book for it.

[electricjohn]

Go for 10* BTDC as a starting point if you can immediatly find the spec for your motor.

[beast]

Check the timing 1st. At the end of last season I was having similar problems. Drop the boat in the water & it would take forever to start. Would crank for minutes then finally stumble & start. After that it would start up fine the rest of the day. I noticed when I replaced the cap/rotor the distributor sensor was really corroded (the module that the rotor passes through) I sprayed some contact cleaner on it it & scrubbed it a bit with a wire brush. Still had starting problems. I went to my buddy who is a boat mechanic & told him what I found & what my symptoms were. I told him what I found inside the cap & he said that was the problem. He said the old style on these distributors are a common problem. Handed me one of these http://www.go2marine.com/product.do?no=116368F (That may or may not be the correct part# but it looks exactly the same) I installed it....engine fires right up on the first crank everytime this year

[86malibu]

do you run regular

[nbeihl]

I just got a timing light in the mail and I timed the engine. There were some specs on a sticker on the engine and it said that 8 Deg BTDC (Before Top Dead Center) was correct. Since the engine has 900 hours on it, I timed it to 10 Deg BTDC. It was set at about 4 After Top Dead Center, which was my problem. Timing fixed everything. It is almost like I put in a new engine. It pulls way harder out of the hole and has much quicker throttle response. It also starts instantly with a flick of the wrist. After timing the engine, I did have to readjust the idle which was expected.

This is the second older boat that I have owned, and this is the second engine that the timing was considerably off. The previous owner probably did not notice anything wrong with the boat because things changed over slowly over 16 years. I would recommend to anyone with a few years on their boat to check the timing. It really takes less than 2 min if you are already on the water...