1972 flywheel/stator question!!

[flacker36]

I'm working on a 72 jd 500 KEC 440 engin serial # 4504465 with denso ignition. It appears someone swapped out the original single spring flywheel/ring gear & stator for a two spring flywheel/ring gear and stator (ND 038000-2130 8K and a ring gear # of 36001310 which they used after serial # 5500000)

My questions are:

1. Is it ok to use the system as it is?
2. Is that ring gear the proper one? (reason I ask is that it appears smaller in diameter and my starter motor will not engage it)


Any help would be great!!

Joe

[flacker36]

The ring gear # (36001310) on my flywheel was used on the 1972 KEC 440 REED engine. Would the ring gear and flywheel both be ND? or did John Deere use thier own ring gear?? Also my engine is a piston port, would that cause any issues like the starter motor not engaging the ring gear (its like the ring gear is too small in diameter for E. S. motor to properly engage it).

Do I time the engine according to the manual or could that all be messed up?

I need help on this one.

Joe

[400brian]

I have a 340/5 that I am changing the flywheel on right now because the starter won't engage it.

The early engines used a different starter location than the later /5s, thus the /5s need a larger diameter ring gear. My 340/5 should have a Koukosan ignition, but it has had a Denso swapped in. The flywheel I removed has 77 teeth on the ring gear, the one I'm putting in has 80. The early flywheel has two arms on the advance, the larger one has a single.

All 72s were piston ported.

I would set it to whatever it is; Denso or Koukosan.

I'll let you know, I'm putting this together tonight.

[flacker36]

Thanks Brian. According to the manual, my engine serial # starting with 4500000 is supose to have the larger single arm on the advance. I guess the double arm advance was used after engine serial number 5500000.

Questions:

1.If I change the flywheel to the single arm advanced denso, do I need to change the stator??? (everything on the engine is denso)

2. Am I ok to use this flywheel the way it is as long as I do not want electric start??

3. If I want to install electric start, do I need to install the single arm advanced flywheel (with larger diameter ring gear) or can I buy just the larger diamerter ring gear and install it on my flywheel??

4. As for timing, Does changing the flywheel change any setting such as points and BTDC? Or should I just set it to the 1972 denso setting in the manual??

Joe

[400brian]

Ok, it seems my memory is only about half right. We had this discussion about 6 or 7 years ago, and I've had the 80 tooth flywheel sitting here that long as well.

I was thinking they changed the starter position with the /5 engines...that is apparently incorrect. The starter studs went to the straight up and down design with the /21, certainly with the /22. So now I'm thinking the 80 tooth flywheel is the early one, and the 77 tooth for the later design.
With the studs located on an angle, it is damn near impossible to get the bottom nut started, the later design is much more user friendly.

I replaced the mag side seal tonight, put the end plate, breaker plate, and 80 tooth flywheel on. Then decided to install the starter. That is where the fun started. I have an American Bosch starter motor, bought it off ebay, it was advertised as off a Deere, but I have no idea what model. I cut a hole in the block off plate so I can use it as the shim, but I can't get a socket on the nuts for the studs, they must have used some special small headed nuts, as there is not enough clearance with the nuts that had held the cover on. Ground a bit of clearance into the starter body, and made it work. Getting a little pissed at this point. Got the support bracket bolted on, and decided to try it.

Hooked the booster pack on, and she cranked real nice, everything seems to be doing what it is supposed to do.
I turned the switch on, and no joy, not so much as a pop. Like you, I am wondering if changing flywheels is going to affect things. I pulled the choke and ground til the battery went dead, nothing. I've got spark, but the plugs are bone dry. I rode this thing on Saturday, but I had a devil of a time getting it to start. It may not be pulling fuel.

On this 340/5, the Koukosan ignition has been replaced completely with Denso, and the later 77 tooth flywheel, and it works fine. I imagine it will run with the 80 tooth, but haven't proven that yet. I haven't checked the timing yet, have to get back to you on that.

[400brian]

Thanks Brian. According to the manual, my engine serial # starting with 4500000 is supose to have the larger single arm on the advance. I guess the double arm advance was used after engine serial number 5500000.

Questions:

1.If I change the flywheel to the single arm advanced denso, do I need to change the stator??? (everything on the engine is denso)

I don't think so

2. Am I ok to use this flywheel the way it is as long as I do not want electric start??

I would say yes. My 340/5 has been running for years with the double arm advance

3. If I want to install electric start, do I need to install the single arm advanced flywheel (with larger diameter ring gear) or can I buy just the larger diamerter ring gear and install it on my flywheel??

I'd suggest getting an 80 tooth Denso flywheel

4. As for timing, Does changing the flywheel change any setting such as points and BTDC? Or should I just set it to the 1972 denso setting in the manual??\

At this point I'm guessing it changes nothing. I'd set it to the Denso specs. I'll post if I find out different on my engine.

Joe

[flacker36]

I would agree, the 80 tooth was the early single arm advanced flywheel and the 77 tooth is the later double armed advanced flywheel. I currently have the angled stud pattern and the 77 tooth which is why my starter motor will not engage the ring gear. When they moved the studs to staight up and down that must have changed the distance between the pinion gear and the ring gear or they used a different pinion gear which was larger in diameter.

I wonder if you could just change the pinion gear on the starter or get a different starter from a different machine (arctic cat???)
Or
Change the housing to the straight up and down one and see if that works??

Looks like I will start looking for an 80 tooth denso 440 flywheel.

Joe

[400brian]

Changing the end plate to the straight up and down version might be another option.

I don't know if changing the pinion is possible.

[400brian]

Set the points and timing as per a piston port Denso. .014 on the points, .015 on the timing. Running strong, idling good. Not starting as good as I'd like, But I'm not sure that has anything to do with the ignition. It's possible I have a carb issue, it doesn't seem like there are enough bubbles going back the return line.

I had to put a thin brass shim between the recoil and the engine ( at the bottom bolt ). The recoil was dragging hard enough on the starter cup that it wouldn't retract. This flywheel sits in a little different spot. The 77 tooth was rubbing on the raised edge that closes the gap behind the flywheel.

[flacker36]

I like the idea of swapping out the backing plate, but then would need to swap out the fan cover shroud as well?? Right now I'm thinking I will try and find the original style denso flywheel with 80 tooth ring gear if I want to install the electric start kit. So if anyone has one that they are willing to let go, let me know.

My 77 tooth ring gear is doing the same thing yours was doing (rubbing on the raised edge).

Joe

[400brian]

E-start is in, and so far so good. The fan towers do seem to have different part numbers.

[flacker36]

Would you happen to have the part numbers for the backing plate with straight up and down mounting bolts and the fan tower that would match up to it?? I just think finding a 72 flywheel with 80 teeth may be harder than these items. I will also post for a flywheel in the classified section.

Joe

[TASKY]

Joe send me an email billtasky@hotmail.com At this time it would be easier for me to send you some pics then to try and resize them and post.