Super Jet Timing guns + Msd enhancers ???

[hydrostyler]

Ok, so I am trying to take every measurable step to get my motor to last more than an hour on this rebuild. I am now venturing into setting/verifying timing. I have a 61x/62t, b-pipe, single 44(for now) 6m6 ebox with enhancer + 61x stator + Zero lightened flywheel. I've read all the threads on here and built a tdc gauge, cut the top off an old f/w cover, built an indicator on the case and marked the tdc on the f/w. I am using an old Craftsman adjustable timing light and started with the stator at 3* advance that most guys run. At 3k rpm I was running at almost 40* according to the light. The engine runs a bit rough at idle but seems very responsive and clean off idle. (haven't been in the water yet) I adjusted the stator back to a couple mm behind the oem arrow to get closer to the 21-24* target. It didn't want to start very easily and ran quite rough. The marks lines up at around 30*. I didn't try to go any further as I would be waaaaay off of the oem marks.

My questions are:
1. How can I verify that my timing light is accurate?
2. Could my Msd be faulty and cause a this timing advance?
p.s. I dont have an oem ignition or I would swap it out. Any help would be much appreciated.

 

[#ZERO]

I would not use the advance feature on your timing light because your rpm advance will be increased early due to the ignition coil firing at every 180-degrees.

Ignition Timing Marks:

In order to mark the coupler in the correct spot, you'll need to use a TDC dial indicator tool through the spark plug hole. Once installed, you'll want to rotate the engine forward & back a few times zeroing the indicator and take some small readings around 0.10mm or 0.20mm in each direction. Then you'll need to mark the engine coupler with a fine line pen in relation to a fixed point attached to the case at each measurement and locate the equal distance between them to find the true top dead center. Then use the piston travel calculation tool below to find the distance for each degree of rotation to create your timing marks. If you have a stock stroke Yamaha engine, just enter 68mm for the stroke and 125mm for the stock length rods with the increments set to five or ten degrees apart to calculate your measurements in millimeters for the dial indicator. Then just use your measurements to mark the coupler or flywheel with the timing line for each five or ten degree increments.

Piston Travel Calculation Tool: http://john.rushworth.com/Pics/Piston/

Here's an inexpensive homemade dial indicator holding tool made from a spark plug with a thumb screw attachment in the pictures.

You can also use the degree wheel method to transfer the marks to your engine coupler but it requires removing the front cover.

 

[hydrostyler]

Here is what I have so far. So you're saying I need to make degree marks on my flywheel based on piston movement/crank rotation, then use my light set at 0 advance to see where I'm at? I can use my standard flaming river light to double check my craftsman light at that point. Have you ever seen a case or stator mark off more than a couple degrees?

 

[#ZERO]

Looks good so far... now you just need to make some more timing degree marks on the flywheel or coupler.

Also you'll have to covert the metric depth measurements from the piston travel calculator to SAE if your dial indicator is in inches.

Yes the stator case timing marks can be off slightly for numerous reasons.

 

[#ZERO]

To be honest with you most people with the MSD enhancer for the yamaha engines just set the stator a few millimeters counterclockwise advanced because the retard rate is only around three degrees total.

If you had a programmable ignition such as the Epic or Advent this method and marking the coupler with degree marks would be more beneficial IMO.

 

[hydrostyler]

Ok, thanks for the info. I'm gonna put a few more marks on the flywheel and see what I come up with using my standard timing light.

 

[Proformance1]

One other thing you can do is measure the diameter of the flywheel, or coupler and put a piece of tape or a sticker on it. Take the total length and divide it into 360 degrees, mark in 5 deg increments. I just do the ones around the 25 deg mark