How to set ignition timing? 1978 Cyclone 340??

[pjr]

Hopefully someone can help me out here..

I just finished replacing the crankshaft seals on a 728-mile 1978 JD Cyclone 340 (KEC-340/22 engine) I've been working on and now I need to re-set the ignition timing via the stator positioning. I see that the stator mounting holes are slotted, where the stator body can be pisitioned on either side of the mounting hole's centerline, so how do I know where to set this thing at statically to make sure the timing is correct?

I don't want to just "put it where it was", as I'd rather make sure the timing is set correctly before it goes back together and the engine is put back into the chassis. I've never done one of these before, but I did stay at a Holiday Inn Express last night...

Thanks for the help in advance!


PJ

[harleysportster]

Here is a good case for needing and using a service manual, but this is covered in the FAQ section of this forum.
http://home.comcast.net/~psshd/cditiming1.jpg
You will need a timing light and a dial indicator to measure the position of the piston in relation to top-dead-center, the timing is 0.096 BTDC
For a starting point, when reassembling the stator to the engine, align the stator in such a manor so the mounting screws are back in their orignal location in the slots. This will at least allow the engine to run.

[ICCSF 108]

PJ, As long as you stayed at a HIE last night the rest will be a cinch..

When your all set up give me a call I'll walk you through it.. By the way are you saying you didn't ck the timing on the Sportfire?

Kenny

[pjr]

Here is a good case for needing and using a service manual, but this is covered in the FAQ section of this forum.
http://home.comcast.net/~psshd/cditiming1.jpg
You will need a timing light and a dial indicator to measure the position of the piston in relation to top-dead-center, the timing is 0.096 BTDC
For a starting point, when reassembling the stator to the engine, align the stator in such a manor so the mounting screws are back in their orignal location in the slots. This will at least allow the engine to run.

Thanks for the info.

PJ

[pjr]

PJ, As long as you stayed at a HIE last night the rest will be a cinch..

When your all set up give me a call I'll walk you through it.. By the way are you saying you didn't ck the timing on the Sportfire?

Kenny

You mis-understood me and you certainly know me better than that... I don't "guess" on anything.....

I said I've never timed a Kioritz engine like this before, NOT that I've never timed a 2-stroke engine in general before- i.e. the Sporty Kawi engine. The Kawi "B" 440 engine has a slot that you align the stator with for the correct timing to be set and then I verified that with my Snap-On dial-back timing light while it was running on our test run-in stand we built. I even added 2* additional advance to crispen up that engine's throttle response, give it a bit more power and to make it easier to start hot or cold. Worked great!

On a side note: My Snap-On dial-back timing light has the capability to pick up the high secondary voltage inductive signal on the leading cylinder to fire the strobe (great for 4-stroke engines, but not so good for erratic 2-stroker's) AND it has an optional feature of a lead to pick up the low primary voltage signal pulse between the stator and CDI. (great for 2-stroke engines or 4-stroker's with magneto's)

I won't have to use the dial indicater method entirely with my high-end light, since it can pick up either signal to fire the strobe to time the engine while it's actually running. Although, setting the timing statically with a dial indicater would be a good starting point to get the engine "running". I guess it's $427 price tag (6 years ago) now made it worth-while to have that extra feature, as it's a pretty trick little piece!


PJ

[ICCSF 108]

Relax, I was just mess'n with you, I didn't misunderstand you, I was just checking being you stayed at the HIE, if you'd pick up on the fact that the Deere Service Manuals for the Kawi engines doesn't give actual timing specs, they just tell you to alien the timing marks..

Kenny

[pjr]

You're right, they don't provide actual timing degree numbers for specs, but when you align the timing slots to get to the static setting, start the engine to obtain the running initial advance at a 2000 RPM idle, (about 18* BTDC if I recall) you can get a reference point to work from. There's more than one way to skin a cat and as I said before, I don't like to "guess" and I want to actually know what I'm working with more accurately other than just using stock "static", mechanical set-points. As a professional auto racing engine builder in this business, it's just my way I guess...

PJ

[harleysportster]

I said I've never timed a Kioritz engine like this before, NOT that I've never timed a 2-stroke engine in general before- i.e. the Sporty Kawi engine. The Kawi "B" 440 engine has a slot that you align the stator with for the correct timing to be set and then I verified that with my Snap-On dial-back timing light while it was running on our test run-in stand we built. I even added 2* additional advance to crispen up that engine's throttle response, give it a bit more power and to make it easier to start hot or cold. Worked great!

On a side note: My Snap-On dial-back timing light has the capability to pick up the high secondary voltage inductive signal on the leading cylinder to fire the strobe (great for 4-stroke engines, but not so good for erratic 2-stroker's) AND it has an optional feature of a lead to pick up the low primary voltage signal pulse between the stator and CDI. (great for 2-stroke engines or 4-stroker's with magneto's)

I won't have to use the dial indicater method entirely with my high-end light, since it can pick up either signal to fire the strobe to time the engine while it's actually running. Although, setting the timing statically with a dial indicater would be a good starting point to get the engine "running". I guess it's $427 price tag (6 years ago) now made it worth-while to have that extra feature, as it's a pretty trick little piece!
PJ

PJ,
From the sounds of things your are familiar with the task but just need some guidance. I suggest checking out this service manual on-line.
http://www.vintagesnow.com/John_Deere_f ... yclone.pdf
Instead of removing the recoil and rigging up a pointer to the flywheel, you could do the same on the clutch side, making a mark on the sheave once you have found 0.096 BTDC. I have successfully used an inductive timing light but you will need a 12 volt battery source if your sled does not have electric start. I had also grounded the negative post of the battery to the sled frame.
Good Luck,

[ICCSF 108]

PJ, That's good info to remember " Sportfire timing 18 Deg BTDC " If I remember right the 80 & 81 Liquifires were also pre-set at 18 Deg BTDC ( at the timing marks ) but ran better at 20 to 22 Deg BTDC ( this is where the Kawasaki sleds were factory set )
I wish that the Kioritz engine specs were in Deg rather than 0.096 as I always use a Deg wheel when I check the timing, & someone once told me that there isn't a working formula to figure one to the other, Maybe because of having something to do with the engine stroke?? I really don't remember what the reason was now??

Kenny

[pjr]

I finished up the '78 Cyclone winterizing project I was working on yesterday, taking the advice from "harleysportster" and marking the primary clutch inner shieve as a reference point to set static timing per JD specs. I found that by marking the shieve as he said, made any re-checking results much more repeatable if the engine's flywheel had to be removed again to make any adjustments, rather than marking the flywheel itself- since things move around to slightly different locations when re-installing all the front engine parts again.

I added 3* more to the final timing setting to sharpen/crispen up the engine and WOWWWW, did that minor adjustment make a HUGE positive difference in increased performance and acceleration!! It starts with just a half-pull on the starter rope and the throttle response is razor-sharp, which is very good for an old-school, vintage engine like this thing has. I think the owner will be very happy with the new results!

Thanks for all the help everyone- I learned something new this weekend!


PJ

[400brian]

PJ

Do you know what that 3* translates to .000" wise?

[pjr]

I have no idea, as I didn't time this engine with that method.

Instead, I brought the #1 piston to the JD spec. of .096" BTDC, marked the inner primary clutch shieve as described by "harleysportster" and ran the engine to get a baseline timing reading using my digital timing light I spoke of earlier. Then I brought the engine to absolute TDC using my dial indicater, scribed another small index line on the inner primary clutch shieve again that indicated 0* TDC and then referenced that mark to a another corrosponding stamping dot I put on the air shroud tin. I used those two permanant marks to now represent 0* (zero degrees) TDC.

Then, while the engine was running again, I dialed-back the strobe pulse to my new marks of 0* (zero degrees) with the timing light to show me what the total timing was at any RPM, as indicated on the digital read-out of the timing light. Once you know where "zero" is, you can now make any adjustment you want, fast or slow, by simply turning the stator counter-clockwise of engine rotation for advance and clock-wise of engine rotation for retard.

In other words, I took JD's odd way of timing this engine and converted it to the much simpler method used in the automotive industry with auto engines. With this much easier (and trackable) method of timing these engines, it will always be dead accurate, no matter if you're performing it on a single-cylinder or multi-cylinder engine- (they're all the same really) as long as you know where the lead #1 cylinder is located and you can establish a true TDC 0* mark to reference from.

Hope that helps.


pj

[400brian]

Thanks PJ.

That is pretty much what I have done in the past, but with a very basic timing light.
Right now, I have a dial back light, but I'll have to figure out how to use it. I don't think it has all the capabilities of yours.
I do have a dial indicator, so that is no problem.

The timing marks you put on your clutch are permanent, as long as you don't remove the clutch.

[pjr]

The timing marks you put on your clutch are permanent, as long as you don't remove the clutch.

That's right, but even if the clutch is removed, the timing adjustment will always remain as long as the stator, nor the air shroud tin isn't messed with that would otherwise screw up the adjustments and move your index marks. Also, it would be very easy to re-mark the clutch to the index mark on the air shroud tin simply by working the procedure in reverse. Any dial-back timing light should work too.

pj

[WinnipegStPaul9]

I have no idea as to anything you're talking about. That's why I don't mess with the engines!!!!