how do I check the timing??

aggiedave98

Petty Officer 1st Class
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Jul 14, 2003
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231
Ok, just replaced the condensor, rotor, plugs, wires, and cap. The points were not in the kit for some reason so I couldn't replace them.<br /><br />Now, I checked the timing. I don't know how to read it. There is a metal piece with 6 "zig-zag arrow tips on it"<br /><br /><br />like:<br /><br />^^^^^^<br /><br />my timing at 600rpm is closest to the 4th arrow tip from the bottom of the boat. What timing is that?? Where is TDC and how many degrees is each mark?<br /><br />Also, my book says to check the centrifugal advance, but there isn't a table in the back which shows what rpm and what the advance should be?<br /><br />Thanks!
 

bigbrownbuku

Master Chief Petty Officer
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Sep 17, 2004
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885
Re: how do I check the timing??

look closer that the tab dave. it should have something to indicate tdc, scratch paint away if you have too. atiming light with an advance function would be useful to help you determine exact timing. it also helps if you post the model of your engine with every post. it helps to better identify your issues.
 

aggiedave98

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Jul 14, 2003
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Re: how do I check the timing??

BenC,<br /><br />Ok, sorry. 3.0L 4-cyl mercruiser in my '88 Invader I/O.<br /><br />I could return the timing light to wal-mart and get one w/ an advance. If I did get one, how would I use that?<br /><br />I'll go back out and look for the TDC mark. Assuming I find it, how many degrees is each of the "arrow tips" and which way is below and above TDC?
 

aggiedave98

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Jul 14, 2003
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Re: how do I check the timing??

BenC,<br /><br />Ok, I'm going to get a bad reputation here...<br /><br />I just wiped all the gunk off that piece and sure enough below it, was all the markings!!!<br /><br />I'm at about 5 degrees BTDC it looks like. The manual says 6 degrees and the light says it's accurate to 2 degrees I believe. So I guess I'm good!<br /><br /><br />One other question... is it ok to put it in gear, when I'm not in the water? I never have b/c I've never been sure, but the manual also says to set the idle speed with it in gear and at idle. Is that right?
 

Boatin Bob

Lieutenant Commander
Joined
Sep 24, 2001
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1,858
Re: how do I check the timing??

It should be in gear in the water (tied to the dock :) )otherwise you won't be putting any load on it. If you set the idle in neutral then in gear it may be too slow and stall.
 

Don S

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Aug 31, 2004
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62,321
Re: how do I check the timing??

In practice, after all your adjustments, set the idle in neutral at 700 to 750 rpm on shore. Then when you go to the water, redo your rpm check and adjust if necessary. It's usually within specs though.<br />Just out of curiosity, what service manual are you using, is it the Mercruiser manual?
 

aggiedave98

Petty Officer 1st Class
Joined
Jul 14, 2003
Messages
231
Re: how do I check the timing??

I'm using the:<br /><br />Seloc<br />Mercruiser Stern Drives 1964-92 Repair manual<br /><br />"covers all type I, MR, Alpha, and Bravo I and II models"<br /><br />Bob, you know, that may be why I've tended to stall when going into reverse when first putting the boat in the water and trying to back it off the trailer...
 
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