Confusing spark problem on early 9.8

Hello all, Im Don, and new to this forum as far as posting goes but have read quite a few posts of late and learned a bit just as a observer but alas it seems not quite enough. I have an older (1969) 9.8 With an intermittent spark problem, it has weak spark at idle setting (turning with a drill) then as soon as I advance the throttle the spark quits and doesnt return till I get past the "start" point. Its still weak at that point then gets hotter the further I advance the throttle.
Ive grounded my shut-off wire (orange) and checked my output wire (green) on the CDI showing 550-900V on the AC setting on my multimeter, and the coils show between .990-1.01 ohms from coil output wire to ground, the points and insolator blocks look brand new and have been regapped to .020. Im kinda at a loss as to why my spark varies so much with throttle movement and quits completely in the "shift" area. any help would be greatly appreciated....OCG

Re: Confusing spark problem on early 9.8

Your motor should not have CDI, if it is indeed a 1969. Should have plain old points, coils & condensers. Please verify year with serial number.

Clean the points, even if they "look" clean.

Check spark plug wires for leakage as that is a common area for intermittent spark loss.

Also, condensers can give intermittent spark issues.

Re: Confusing spark problem on early 9.8

You are correct, I just double check the ser # and its a 70, its definitely CDI and I just had a thought, Im wondering if the stator could have be reinstalled wrong when the points and insolator blocks were replaced? could it be clocked 90* out?....ocg

Re: Confusing spark problem on early 9.8

In most cases the position of the stator does not matter but when the spark comes and goes when you move the timer you have a bad wire from the timer to the coil. You can remove the wires from the points to the coils at the coils and hook a jumper wire to the coils 1 at a time have someone pull the engine over and arc the wire to ground, you should have a good blue spark each time it's arced.

Re: Confusing spark problem on early 9.8

Both leads from the points have been replaced (as have the ground wires}, I guess the next step would be to check them for continuity while moving the throttle back and forth. I used automotive wire and it was slightly larger cored and with thinner insulation I wonder if given the high voltage they could somehow have an inductance to ground problem? they do fit very tight where they pass through the points housing...Im kinda grasping at straws here...OCG

Re: Confusing spark problem on early 9.8

The larger wire used could be the trouble, but if the insulation is of a good standard they should be fine. After testing as Chimewalker states you very well might find a spot when the linkage gets to where you lose the ground and it might be that those wires are what is causing the trouble. The points on that ingnition only put ground to the coils and are very touchy about the setting of them. If they are not set just right they could be not opening when they need to be . I try to never move the points and just clean them. The wires where they conect at the small nylon block for the points could be cracked and cause the trouble also. There should be a ground strap wire from the stator plate bottom to the block that is bd and moving when the plate moves. When everything is set correctly those motors run great and are a PITA when something goes wrong. The last on I worked on took me 3 days to get everything set just right as to PO had moved the points and everything was way out of whack.
Oldman570

Re: Confusing spark problem on early 9.8

Ive got new ground wires going from the points housing to the bottom of the stator housing and then directly to the engine block so the points dont have to depend on moving linkage to maintain ground so Im pretty sure that part is good. and the points and insulator block look brand new and theyre gapped at .020. Im wondering if this stator has hi-speed and lo-speed charging coils?...ocg

Re: Confusing spark problem on early 9.8

No I don't belive they do, but not forsure about that. If they do and you have to get a new one you might want to get a few cold one in ya to take the sticker shock. I had to replace the one on the motor I worked on as all the insulation was falling off and therre was a burnt spot in the encapslent that caused one plug not to fire even at idle. The coils for the motor are not cheap neather, around 90$$$ for just one if you can find one new. Otherwise used coils can be as bad for two with a warrenty. There is only two coils# that will work on the motor. Best of luck and I do have a coil if you need one.
Oldman570

Re: Confusing spark problem on early 9.8

Here's the test for your engine from CDI maybe it will help you

Re: Confusing spark problem on early 9.8

Oldcraneguy said:

Im wondering if this stator has hi-speed and lo-speed charging coils?...ocg

Click to expand...

Yes it does. My 71 20 had a bad high speed portion. It would idle ok but would not run at high speed.

Re: Confusing spark problem on early 9.8

I believe my stator has problems but I hate to put another $250 into a $250 motor without knowing for sure, even if it fixes the problem that wont make it a $500 motor and I'll be married to it! It might be time to either part it out which Id hate to do or just put it on the back burner and keep a look out for a used stator....ocg

Re: Confusing spark problem on early 9.8

It's easy to test that stator without any special tools, do the test in the page from CDI labeled No Spark Any Cyl. or my first post and if you don't have spark it's the stator and if you do it's a component of the timer.

Re: Confusing spark problem on early 9.8

Hi Don. How's the wire from the stator? Sounds like it's an issue where the signal to fire is being interrupted ...like a cracked wire somewhere close to ground and then breaking from ground...creating a timing problem. What condition is the stator itself in? Are flywheel magnets all in place and secure and clean and still strong [screwdriver test ---good magnetism at one inch]? Same for the stator coils.