Wombat Ignition Timing

[kitjv]

The ignition timing on Model 94/94A Wombat is 2.4mm BTDC. Is this timing fixed or can it be adjusted?

Thanks.

Kit V.

[Dale]

Kit,
The adjustment is made by setting the point gap. Here is a link to a nice write-up, provided by Max here on the forum, on how to set the gap.

viewtopic.php?f=1&t=1101

[Zyx]

To answer the question asked, it is adjustable although not while running, and there is no advance curve. Timing is static. 2.4mm would be a target if you set timing with a dial indicator. Otherwise set the points to break open when the reference mark on the flywheel is aligned with the right hand reference on the case.

[kitjv]

Thank you, guys. my question was a bit unclear. I should have asked whether there was an adjustable timing advance. I assumed that the only adjustment was the point gap. Question answered. Thanks again.

[RichardMott]

When we were at HD15 setting up Stu Gillard's Wombat, Greg Watkins had a nice little timing light. Worked great to get it spot on.

[Zyx]

Yes he did, and I can't find one like it anywhere. Even with that light it took me ten minutes to zero in the timing. I think it might have been quicker to use a multimeter and set the point break statically. What the light shows is running timing, which takes into account mass in motion, electrical resistances and such that can make timing change slightly while operating. Fastidious timing would be set gap with a feeler to get it roughly right, set with an analog meter to set the break, and verify with a light. I wouldn't have had time to do all that back when I was working on the clock, but now that I am retired, I can piddle with it all day until it suits me.

[RichardMott]

I think this is like the one Greg had;


http://www.amazon.com/Wilmar-W80578-Sel ... ming+light

Amazon is a great site to find almost anything....

[junker2k]

The easiest way for me to set the point gap is to set the gap. I have flywheel cams for both the 100 and 125 that Hodaka sold in the 60's and 70's.
Pull the flywheel off, push the cam on, turn the crank so the cam opens the points to the widest point set the points at .012 to .015 (I set mine at .013)
put the flywheel back on and go ride. For a full out race bike may want to use a dial to get it where you want but most likely if it is a full on racer you are not using point. This can be done without pulling the flywheel by looking through the slot.
Jack K

[bobwhitman]

Jack-

How'd you get the cams? Did you destroy a flywheel?
Bob

[Dale]

Bob,
I do not own one, but I did see where Hodaka-Parts has them listed for sale. Search for "Ignition point gap tool". I have an old flywheel that was clearly marked "bad" when I received it in a box of miscellaneous parts and have considered making one from it.
Dale

[RichardMott]

Pardon my hijack, but I saw the tool posting and had to check it out. Yes, Hodaka-Parts.com has such a tool. $86.00....Ouch!

http://hodaka-parts.com/item.asp?cID=0&PID=3411

[hodakamax]

I found this interesting that Harry Taylor did indeed make the timing adjustable for battery ignition as shown in his road racing bulletin from the past. I went this route for my short tracker of the day but went back to a flywheel for better starts and reliability. The bike produced more power and was quicker reving but it didn't always get to the first corner first. Ah memories!

Max

PS--I still have my 913007R point cam from the era!

[taber hodaka]

Max you must have saved everything. I still have my point cam but ours are the real McCoy and they do not have the holes on the outer edge.======= Clarence

[Zyx]

Setting timing by point gap only sets only approximate timing. That's why the spec is anywhere between 0.012 and 0.015, yet timing is correct at only one point. So which gap is correct, you ask? Whichever gap achieves correct timing is the correct gap. If approximate is good enough for you, its fine by me.

[junker2k]

AZ
I was sure this would come up! The flywheel marks and the case marks are not matched for each motor, they are approximate and that is if you line up the marks the same way each time. The only way to get exact is with a dial in the spark plug hole and a light. But for the 99% of us setting it by the book at .012 and .015 will make the bike start and run fine. I set mine at .013 to allow for some ware so I don't have to set every week. With my flat tracker in the 60's with total loss ignition and a slotted backing plate, Harry had set it with it dial and light then told me what the gap was to be set at. But each to his own.
Jack K

[Zyx]

The gap changes with time due to wear, and changes every time you replace points due to tolerance differences, so no matter what Harry said, setting point gap doesn't set timing, it only gets you running. If that's close enough for you, go for it. And, last time I checked, my flywheel marks coincided with my dial indicator.

[Dale]

Greg,
Your marks coincided with your dial indicator? That must be nice. I have seen a number of cases that were not marked correctly. This has been discussed on earlier posts... I have set several motors up to break at the righthand mark only to be disappointed in the performance. After checking with a dial indicator and finding the mark to be off, I reset the points to my new mark and was good to go. That said, I have never had an issue setting the gap to .013 and as Jack said "go ride". With the tolerances and wear of all of the moving parts, setting the points within a nats eyelash of perfect makes no sense for most riding situations. Yes, to each his own.
Dale

[hodakamax]

A little more info on Harry Taylor's road racing bulletin on adjustable timing. The points were set first at .010" and then the timing was set by rotating the plate to break the points at 25 degrees BTDC. I'm guessing this was to reduce point bounce at high RPMs.

Max