Sprk timing--E140TXCDC

[Rscardina]

Hey guys,

Just wondering if there is a way to tell if your spark timing is in or out? Meaning, is there a place to look to determine if you are on when cyl 1 is at TDC?

I've read the manual instructions and it calls for test tank or out on the water at high rpms etc... I'd like to get some input from you guys as to what people do who dont have test tanks or special props to adjust all of this stuff.

Ideally i'm looking to see if i am close or on and then be able to take her out and make incrimental adjustment when she is actually running..if that make any sense whatsoever..????

I've also read the sickys that tashasdaddy posted (joe reeves method)..and its in boat jargon so i dont fully understand the procedure..

Thanks

 

[Rscardina]

Re: Sprk timing--E140TXCDC

Anyone....??

 

[Dhadley]

Re: Sprk timing--E140TXCDC

The timimg pointer is at the front of the motor around the intak manifold area. Set the pointer as per the manual and then set the wot timing as per the manual. Do not exceed the recommended timing. Make sure you use the 1986 / 87 book, not the 1985 book for the V4 looper.

 

[Rscardina]

Re: Sprk timing--E140TXCDC

I have the 86 shop manual.. I read front to back and eveything on timing or spark advance talk about actually running the engine at WOT..

So my original question was just to see if there is a way to check the setting without actually running it ...meaning, if i set the 1 cyld at TDC..should the pointer be close or dead on the casting mark TDC?

If I then turn the flywheel by hand to the next cylinder in the order...would I see an indication of where the spark would be ....meaning TDC of 2..and the marker should line up???..

At the end of the day all i am curious to know is if there is any way to tell where spark would be firing if the engine wasnt actually running??..i guess a proof of the timing being on or off..??

 

[fixmyevinrude]

Re: Sprk timing--E140TXCDC

You mention in your last post that ["if i set the 1 cyld at TDC..should the pointer be close or dead on the casting mark TDC?"] It should be dead on TDC assuming you actually have the #1 cylinder at TDC. When you go to the #2 cylinder and set it at TDC ( I am not sure I understand why you want to check the #2 TDC) the pointer should be what ever degrees difference the crankshaft was made at for the firing order for your particular engine. That is not going to tell you where you are firing at. That is going to be determined by where your spark advance is set. By seting your pointer for TDC for the #1 cylinder you are basically calibrating a gage and then you use that gage to set the timing to the proper specification. I am not a mechanic and if I am steering Rscardina wrong please correct me.

 

[Brew2]

Re: Sprk timing--E140TXCDC

Hi,

You'll have to do a search, but somewhere in this forum you will find instructions posted by Joe Reeves on setting time for your looper without having it at WOT.

Used this procedure on my 1986 140hp and it worked perfectly.

If you can't find it, start a new thread titled something like "Looking for Joe Reeves Timing Instructions" and I'm sure someone will have them.

Good Luck.

 

[Rscardina]

Re: Sprk timing--E140TXCDC

thats where i am confused a bit... so, if cyl 1 at TDC matches the TDC stamped on the flywheel does that then mean it is also where sparking should or would occur?..

My second statement about turning the flywheel so the next cylinder (2) goes to top of its stroke.. was to determine if the two will match on the stamped flywheel.. and so on and so on..

assuming each quarter turn sparks 1 cylinder you will have 4 points of spark for each revolution...

so again forgive me if i am asking it incorrectly, but how would you know you are getting spark at a precise moment in the revolution...?? thats the reason for the question.. if there are indications on a flywheel, then I assume they correspond to a position in the firing order...

my hope was that one could manuallt turn the flywheel and see that thing line up a certain way to know if its way off or on...???

I'm sure i am not asking this right...

PS..I found that post and that is what sparked my post...I didnt quite understand the jargon..

 

[fixmyevinrude]

Re: Sprk timing--E140TXCDC

To answer your first question in your last post: no that is not necessarily where spark should our would occur. I believe your are confused on two separate procedures that are integral to each other for correct timing. So first you must be certain that the pointer is at 0 degrees when the #1 cylinder is physically at TDC. Secondly you must correctly set the spark advance. I don't know what the timing is for your motor but I will say for demonstration purposes it is 17 degrees BTDC. ( I did not look this up so check for your specific motor) Then if you follow Joe Reeves procedure I think you will be on the right track. If you want to get an idea of how the mechanism for the timing works remove your motor cover and with the engine off have someone slowly accelerate the throttle. If you watch the carburetor linkage you will see some rods and rollers that move some mechanisms that are under the flywheel. Those mechanisms under the flywheel are what actually advances the timing and tells the spark plug just when to fire. You must also understand that the timing is different at idle than it is at wot. Joes method sets it for wot and the rest of it will take care of itself. His method tells you to set the timing 4 degrees less than stated because you are setting it at cranking speed rather than wot rpms as the timing spec is designed for. His method compensates for this so you can set it at home on your trailer and still be accurate. You also only need to set timing for the #1 cylinder, all the rest will take care of themselves. I hope I have helped clarify this somewhat for you.

Your second statement I cant completely answer because I do not no for certain that it fires every 90 degrees. I would assume it does and yes it will fire four times per rev.

I believe you are on the right track but it might be a good idea if you could find someone familiar with this to help you the first time. Its hard to explain everything in writing since I am not a technical writer. Best of luck and if you have more trouble or questions feel free to ask.

 

[Rscardina]

Re: Sprk timing--E140TXCDC

To answer your first question in your last post: no that is not necessarily where spark should our would occur. I believe your are confused on two separate procedures that are integral to each other for correct timing. So first you must be certain that the pointer is at 0 degrees when the #1 cylinder is physically at TDC. Secondly you must correctly set the spark advance. I don't know what the timing is for your motor but I will say for demonstration purposes it is 17 degrees BTDC. ( I did not look this up so check for your specific motor) Then if you follow Joe Reeves procedure I think you will be on the right track. If you want to get an idea of how the mechanism for the timing works remove your motor cover and with the engine off have someone slowly accelerate the throttle. If you watch the carburetor linkage you will see some rods and rollers that move some mechanisms that are under the flywheel. Those mechanisms under the flywheel are what actually advances the timing and tells the spark plug just when to fire. You must also understand that the timing is different at idle than it is at wot. Joes method sets it for wot and the rest of it will take care of itself. His method tells you to set the timing 4 degrees less than stated because you are setting it at cranking speed rather than wot rpms as the timing spec is designed for. His method compensates for this so you can set it at home on your trailer and still be accurate. You also only need to set timing for the #1 cylinder, all the rest will take care of themselves. I hope I have helped clarify this somewhat for you.

Your second statement I cant completely answer because I do not no for certain that it fires every 90 degrees. I would assume it does and yes it will fire four times per rev.

I believe you are on the right track but it might be a good idea if you could find someone familiar with this to help you the first time. Its hard to explain everything in writing since I am not a technical writer. Best of luck and if you have more trouble or questions feel free to ask.

I apreciate the help..I think i know what you are saying. I think my manual called for 18 degrees +/- 1 ..so based on your explaining joe reeves is saying retard the advance by 4 or set it to 14 degrees..at WOT position.. having the top end set will effectively take care of the bottom by default..

so, if you could help with one other thing..?? the reason for my thinking of 4 spark per revolution was based on the old rotator cap and point setup.. as the rotator spins it engges and disengages each point in a sequential pattern.. so moving to a magneto cdi setup the same principal must exist as you still need a spark for evey cylinder at differnt strike points..having said that I asumed 4 cylinder is equivelant to breaking the flywheel into 4 ..

so if i envision a pie..then at some point in each quadrant you need a spark..this i assume is why you set 1 at TDC to start the pie..(just my way of painting a picture)

so the queston..what is 18 degrees?? is it as I envision as the pie is disected into 4- 90 degree slices and the 18 represents the angle between the center line of the wheel and 14 degrees off center is the spark advance (per joes posts) ??

Thanks a bunch..once i paint the picture i think all will fall into place..and I do have someone who can help as well.

Thanks!

 

[fixmyevinrude]

Re: Sprk timing--E140TXCDC

I believe you are evvisioning it correctly. Perhaps someone else will also chime in here and give us there perspective. In a nutshell the plug fires 18 degrees before the piston reaches TDC.

 

[jonesg]

Re: Sprk timing--E140TXCDC

I apreciate the help..I think i know what you are saying. I think my manual called for 18 degrees +/- 1 ..so based on your explaining joe reeves is saying retard the advance by 4 or set it to 14 degrees..at WOT position.. having the top end set will effectively take care of the bottom by default..

so, if you could help with one other thing..?? the reason for my thinking of 4 spark per revolution was based on the old rotator cap and point setup.. as the rotator spins it engges and disengages each point in a sequential pattern.. so moving to a magneto cdi setup the same principal must exist as you still need a spark for evey cylinder at differnt strike points..having said that I asumed 4 cylinder is equivelant to breaking the flywheel into 4 ..

so if i envision a pie..then at some point in each quadrant you need a spark..this i assume is why you set 1 at TDC to start the pie..(just my way of painting a picture)

so the queston..what is 18 degrees?? is it as I envision as the pie is disected into 4- 90 degree slices and the 18 represents the angle between the center line of the wheel and 14 degrees off center is the spark advance (per joes posts) ??

Thanks a bunch..once i paint the picture i think all will fall into place..and I do have someone who can help as well.

Thanks!

I think the flywheel goes all the way around before firing the next cylinder, its different from a 4 banger distributer cap, it has to generate the juice to fire the next plug, and it doesn't fire until the powerpack tells it to.

Misfire or crossfire is a powerpack problem if timing is set properly and plug wires aren't crossfiring from being too close or worn insulation.
Misfire can happen when components start to break down in the powerpack.
Doing a spark test on all cylinders at the same time will show crossfire.

Anyway, look at this.
It helps when you see it done.
www.themarinedoctor.com/videos/statictiming.wmv