Why is Timing Out of Time?

[milkyway]

Merc 5.0 1999 TBV Ignition<br /><br />I set the ignition to base timing by grounding the white nad purple wire. I adjusted the idle mixture and the speed screw until the rpm was the desired 650. Using the digital tachoter which has increments of 10, the rpm fluctuated between 650 and 675. This happened even after removing the base timing. Is this fluctuation acceptable??<br /><br />Now on timing - 10BDTC, using advanced timing light set at 10 degs. I turned the distributor until the rotating mark and reference mark were aligned. There was a slight swing back and forth, but very slight. When I removed the base timing, the swing became more spread, like an inch spread, before and after the reference mark. Tried second time, it did the saem thing. What could be the reason?

 

[Don S]

Re: Why is Timing Out of Time?

Now on timing - 10BDTC, using advanced timing light set at 10 degs. I turned the distributor until the rotating mark and reference mark were aligned. There was a slight swing back and forth, but very slight. When I removed the base timing, the swing became more spread, like an inch spread, before and after the reference mark. Tried second time, it did the saem thing. What could be the reason?

Gee, ya don't suppose they wanted you to put it into base timing mode for adjustments so all that movement would stop do you?<br /><br />Get the Mercruiser service manual for your engine and read it. It eplains WHY all this stuff happens and why and how it works.

 

[milkyway]

Re: Why is Timing Out of Time?

Don --- I am screaaming help! I will be on vacation starting this Thursday. If I read the service manual which I still haven't bought yet (using Seloc and other literature), I will never be able to get out. I know this is engine 123 to you, still, can you please assist me here? I don't want to put this on water on Thursday and make unnecessary damage.

 

[milkyway]

Re: Why is Timing Out of Time?

Anyone not related to Don and willing to give me some pointers? I will still take this boat out on Thursday to relieve me from anxiety. I thought when I have replaced the plugs, wires, separator, filter, done timing, I could proceed to an enjoyable summer. Gotta make some extra money and get one of those striper boats that have twin yamaha 4 stroke outboards.

 

[Don S]

Re: Why is Timing Out of Time?

Yea, them Yams are what 2000 maybe $3000 each right? NOT, can you say close to $15,000 each, and if you think they need no repair, man have you go another thing coming.<br /> Go ahead, put your boat in the water, you won't pay attention to what was said above. It's doing what it should be doing. You take it out of base timing and it will move around. That is why they are put into base timing mode. To lock things in so they can be adjusted without moving around.

 

[milkyway]

Re: Why is Timing Out of Time?

I thought you were just being sarcastic on your first statement "Gee, ya don't suppose they wanted you to put it into base timing mode for adjustments so all that movement would stop do you?". You're The Man. Time to check the trailer and grease and get some fun. My wife squirms at me whenever I have to go to marine store and buy that, buy those, give her all the receipts, and spend a lot of time hugging the engine. My friends have advised me to get outboards coz they're much easier to work on. So I am looking. My wife agrees and my body aches everytime I do something on the engine. You are here in forum because boating and engines are your passion. Thanks again.

 

[pilotkeith2000]

Re: Why is Timing Out of Time?

As usual Don S is right Again. Just wondering??Who moved your base timing anyway? I read alot of posts on here that folks with running condition problems after winter storage think must be base timing. If it was set when you put it up...its still set! I am not a boat tech but am an auto tech. I have several customers a month that when it starts running bad they always want to know How much to set my timin man ? Bout 500.00 bucks dude we'll get running good... lol

 

[pilotkeith2000]

Re: Why is Timing Out of Time?

Yea those outboards are easy..are you kiddin? You find a good outboard tech.. He'll be the guy working in 105 degree weather with 98 percect humidity and not sweating one drop. They are not from this planet!

 

[milkyway]

Re: Why is Timing Out of Time?

No one moved the base timing. Can it be changed? Just to lock the ignition module. I was just asking Don to verify the results of my "fist-time-ever" timing job. And this is exactly why people come here for some help -You charge $500?

 

[Don S]

Re: Why is Timing Out of Time?

Sure you can move the base timing. Just loosen the distributor and turn it either direction and watch your timing mark.<br />No, we don't charge $500 to check timing.

 

[pilotkeith2000]

Re: Why is Timing Out of Time?

I was just kidding about that. Just a lot of people jump to the assumption that timing must be the proplem. Hope you have a great summer and tons of fun on your boat.

 

[rodbolt]

Re: Why is Timing Out of Time?

I am with piolotkeith.<br /> I get it daily.<br /> how much to set the timing orthe classic"all it needs is a little adjustment".<br /> folks once something is set it stays set unless someone physically monkeys with it.<br /> if its broke its broke, tell the tech/service writer all the info. if ya got it hot tell them, they will figgure it out anyway and at 75-100 bucks an hour its cheaper if ya just thell me what ya did to break it.<br /> the reason to lock certian ign systems into base timing is due to the electronic advance curve, as RPM changes timing will change accordingly.<br />with no base lock every time you alter the physical location of the dist body the timing and RPM change resulting in no clue where the spark is actually occuring.<br /> I had a volvo TBI come in last summer with a hole in a piston, the guys had tried to "power" time it at WOT in the water.<br /> best I recall when I checked base timing was about 42* BTDC.<br />even with all the safeguards they managed to destroy the motor. the ECU assumes its information is correct.

 

[I/O WALDO]

Re: Why is Timing Out of Time?

Mercruiser electronic base timing only changes if there has been a mechanical failure such as dist.problem or cam timing change.(on a dist.equipped engine of course!)

 

[bruceb58]

Re: Why is Timing Out of Time?

On my Volvo 7.4L "LK" series. You can't change the timing even if you wanted too. Turning the distributor wouldn't do a thing. Timing is set by the EEM and the timing pickup on the flywheel