Timing issue??

I have had a few different issues with my 1999 Bayliner 3.0L that I am trying to figure out if is timing related. I purchased the boat a month ago, so it is new to me. Maybe they are separate issues, but not sure. Here are a few things I have noticed:

1) When I hit the throttle to get up to speed, there is a slight hesitation. After it hesitates, it get's up to speed without any further issue.
2) After I run the boat for a while and turn it off, it will continue to run for a couple of seconds after I turn off the key. Occasionally, it will backfire as well.
3) My top speed is around 35(confirmed with GPS), but the previous owner said he had no problems getting in the high 40's.

Again, not sure if these are separate issues or not, but thought I would assume that they are maybe related until I can start to find some answers.

Re: Timing issue??

1) When I hit the throttle to get up to speed, there is a slight hesitation. After it hesitates, it get's up to speed without any further issue.

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Most likely an idle mixture adjustment. A little too lean or rich can cause the hesitation.

2) After I run the boat for a while and turn it off, it will continue to run for a couple of seconds after I turn off the key. Occasionally, it will backfire as well.

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With the 3.0L engines, this is most likely caused by 1 or 2 things. Idle rpm too high (anything over 700 is suspect) and not allowing the engine to idle for a minute or two to cool off after a good run.

3) My top speed is around 35(confirmed with GPS), but the previous owner said he had no problems getting in the high 40's.

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Do you trim it properly?

Timing could cause the problems, here is info on the ignitions system of your engine.

View attachment 3.0 EST timing.pdf

Proper idle timing depends on the serial number of your engine.

Re: Timing issue??

Don, I was going to post the trim issue on a separate thread, but oh well.....If I trim up the drive a little, the propeller starts to spin out of the water and I lose speed. Not sure if there is another adjustment, but I assume that isn't normal. Basically, I have to trim all the way down to not have any issues with prop losing grip in the water.

Re: Timing issue??

Rico23 said:

Don, I was going to post the trim issue on a separate thread,

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Good idea. With a title like Timing Issues, you wouldn't expect to find trim problems.

Re: Timing issue??

Well, on a hunch, I pulled the spark plugs to check the gap. They were all over-gapped by .005. Not sure how much of a difference it will make in my issues, but it can only help.

Re: Timing issue??

Rico23 said:

Well, on a hunch, I pulled the spark plugs to check the gap. They were all over-gapped by .005. Not sure how much of a difference it will make in my issues, but it can only help.

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If you really mean .005, then that will make no difference at all. What brand of spark plugs? It is probably a good idea to simply replace them with new AC Delco or NGK plugs.