Maximum Spark Advance.

[Basscat 1]

Doing a link and sync. my books says to use a test wheel while checking the maximum spark advance or incorrect timing results may occur.<br />Can anybody explain this? Is there anyway of doing this check without a test wheel?<br />In the search tool, somebody mentioned that Joe Reeves has a method, but I couldnt find what they were talking about.<br />Thanks.

 

[OBJ]

Re: Maximum Spark Advance.

Basscat.....here's what ya' do.<br /><br />Remove the spark plugs and rig a spark tester to give the plug wires a place to spark to.<br /><br />Make sure the battery is up....<br /><br />Go to wide open throttle without shifting into forward....this may require disconnecting the shift cable.<br /><br />Hold the throttle at WOT...wire it up if you have to.<br /><br />Connect the timing light to #1 cylinder and crank. Set the timing for 4* less than what is called for....if it's 28*BTDC...set it at 24*....the pack will take care of the other 4*.<br /><br />First time out you can recheck it with a timing light. Remember, you need to be at WOT with at least 5K rpm on the water.

 

[Basscat 1]

Re: Maximum Spark Advance.

Originally posted by OBJ:<br /> Basscat.....here's what ya' do.<br /><br />Remove the spark plugs and rig a spark tester to give the plug wires a place to spark to.<br /><br />First time out you can recheck it with a timing light. Remember, you need to be at WOT with at least 5K rpm on the water.

Two questions.<br />Only the first plug wire would need to be rigged to spark, correct?<br /><br />If you tested it on the water at the lake, wouldnt it be the same if you tested in a water tank at home?

 

[OBJ]

Re: Maximum Spark Advance.

No....you need a place for all the sparks to go or you risk frying the ignition system.<br /><br />No....it's not the same. In the water (like a lake) the engine is under load....pushing the boat. In a tank at home, there's no load on the motor....just the prop pushing water around. You could probably get 5k rpm with just a little over half throttle in a tank and what you need it WOT...the control all the way forward with the timing base all the way advanced.

 

[ED21]

Re: Maximum Spark Advance.

That's the "Joe Reeves" method I used to time my 40 after a link & synch and it worked like a charm. The motor runs well & even though I've never tested with a light on the water, I'm confident the timing is correct.<br />The test wheel puts to proper load on the engine.<br />I understand they are not cheap. $150 or more, but I never priced one.

 

[Basscat 1]

Re: Maximum Spark Advance.

Thanks a lot, I will give it a try, maybe this weekend.

 

[kirkland]

Re: Maximum Spark Advance.

I'm about to be in the same boat .....but how do you rig a spark tester

 

[ED21]

Re: Maximum Spark Advance.

Do a search on iboats for spark tester & you should find some good descriptions & a nice picture from not to long ago.<br />On my 2 cylinder motor & just took the spark plugs out & wrapped some heavy wire around the base & grounded them.

 

[marinemech1]

Re: Maximum Spark Advance.

the crank method gets timing close<br />the only way to be sure is run engine under load over rpm specified in manual because of electronic advance (its a condition that happens when magnets speed up thats why they give a min rpm)