Pick up coil issues

[Jhbox13]

Greetings all. I'm new to the V-Max land but have a decent history with other bikes. Just got a. '85 VMX12, and am having a bit of an issue.

The bike took 24 hours of Marvels Mystery Oil to free up the pistons, no big deal. Turns over well but looks like I am missing fire on the #2 (front left?) cylinder. Tested the coils (all of them) and all are in spec for resistance (primary and secondary both).

I when testing the pick up coils I am getting a big fat ∞ on the W/G the others are all in spec. (picture of offending pickup coil in the attached image)

So here is my question:

I was under the impression that there are only 2 pickup coils, 2 coils per pickup. Soooo, the pickup itself is probably ok because the other ignition coil is getting fire. My issue with coil #2 is most likely ....just a connection issue?

Just trying to see if my logic makes sense here, or if I'm wrong about the number of pickups.

If the pickups need replacing, where do I get the darn things? Can't seem to find them on the net

 

[one2dmax]

The pickup coils on the 85-89 are very stable and usually don't fail (the 90-07 is a different story). The CDI boxes however are prone to failure in your year 85-89 range (the 90-07 is actually durable).

 

[Jhbox13]

Roger that. I guess I'll see if I can diagnose a for sure connection issue on that wire, otherwise I guess I need to find a cdi

 

[Jhbox13]

Actually, don't think it can be the cdi. I'm not getting continuity at the 5 prong plug up by the solenoid, where it does down to the last side cover. Problem has to be down there

 

[one2dmax]

Check the connections but I can tell you from 30 years of experience specifically with this bike that the CDI is most likely the culprit (other possibles are the sidestand safety switch and sidestand diode but those are not as likely). The other main issues these bike have is with carbs.

The CDI's fail in a number of ways.

I do have an electrical loaner program by the way as well to test with. You have the option to buy whatever part(s) fix the issue.

 

[Jhbox13]

I'll let you know what I find. It seems unlikely to be the cdi when it's not in the loop of where the failure is occurring.

How many pickups do these bikes have? Looks like two to me, but perhaps I'm misinformed.

 

[Fire-medic]

I believe the 1985-1989 have two pairs (4 total) while the 1990+ has one.

 

[Jhbox13]

Gotcha, I'll take the cover off today and check out the offending pickup coil. I'll let you guys know how it goes

 

[sdt354]

Gotcha, I'll take the cover off today and check out the offending pickup coil. I'll let you guys know how it goes

There is a mistake in the manual regarding what wire s to check at the pick up harness connector. Usually they work or they don't. +1 on when miss-firing on just one cylinder, it's highly unlikely the ignition pick ups are faulty. Got juice on one side of the 2 wire coil plug, on that bad cylinder, with the key on? If so, I'd swap the TCI out. I'd take Sean's generous offer on the kit, or I'm sure one of us has a box you can borrow. Many of us have upgraded to Ignatech or Dyna digital boxes.
Steve-o

 

[Jhbox13]

Yeah I had read about the mistake in the manual, and checked the pickups with the actual ground wire instead of what the manual suggested.

Coil checks out, so I don't think there is a problem. Like I said, I am getting no continuity from the plug down to the pickups, while out of the loop with the cdi, so I doubt it has anything to do with a failure that it isn't actually plugged up to. That being said, I am sure that the cdi may indeed be bad. But I'm going to run this problem down before I start throwing parts at the problem.

Its probably is just a bad connection, not to mention one important thing that I recalled. The guy I bought it from said he replaced the stator, and quite frankly he didn't seem all that bright. My bet is he managed to mess it up somehow while bumbling around in there, because I agree that pickups rarely just "go bad" with no outside intervention.

 

[93max]

Yeah I had read about the mistake in the manual, and checked the pickups with the actual ground wire instead of what the manual suggested.

Coil checks out, so I don't think there is a problem. Like I said, I am getting no continuity from the plug down to the pickups, while out of the loop with the cdi, so I doubt it has anything to do with a failure that it isn't actually plugged up to. That being said, I am sure that the cdi may indeed be bad. But I'm going to run this problem down before I start throwing parts at the problem.

Its probably is just a bad connection, not to mention one important thing that I recalled. The guy I bought it from said he replaced the stator, and quite frankly he didn't seem all that bright. My bet is he managed to mess it up somehow while bumbling around in there, because I agree that pickups rarely just "go bad" with no outside intervention.

When I had my 2010 KTM SXF 450 the PU would go bad once up to operating temp.
Heat makes resistance. Checked out fine when cold and would fail when warm.
I would crank the piss out of that thing and it wouldn't start when hot.
$25 later all was well. The TPS had to be in the rt spot also otherwise it would advance the timing and slow crank.

 

[Jhbox13]

So gents, do you recall the statement being made by myself and a few others to the tune of "pickups don't usually go bad"? Well it is a good thing that its not a typical day here in Austin, because I got a nice surprise on the 2/4 pair when I pulled the assembly this afternoon (see pics)

So with that out of the way, it looks like I will need at least the 2/4 pair, preferably the whole assembly. Anyone around these parts have a good deal on it? I saw that there a few regular looking types around here that seem to deal in parts. Surely theres a salvage engine around here with a set of pickups for cheap.

 

[one2dmax]

I've got a bucket for that ill sell you as many as a couple of dozen if you want. They don't go bad often so I would guess that was a user error issue.

 

[Jhbox13]

I've got a bucket for that ill sell you as many as a couple of dozen if you want. They don't go bad often so I would guess that was a user error issue.

Sounds great! I messaged you through MorleysMuscle as well today. I would love to get ahold of one, what is the best way to get ahold of you to hash out the details?

 

[one2dmax]

As always the emails are best. [email protected] (your part should go out on Monday)

 

[vmaxed1989]

When I had my 2010 KTM SXF 450 the PU would go bad once up to operating temp.

Heat makes resistance. Checked out fine when cold and would fail when warm.

I would crank the piss out of that thing and it wouldn't start when hot.

$25 later all was well. The TPS had to be in the rt spot also otherwise it would advance the timing and slow crank.

Reading this with interest. I have an 89 max with 23000 on the clock. Can’t seem to solve the erratic tick over when warm. Ht coils are changed, balanced carbs but still get this problem when warm. Starts easy if it should stall goes like stink. Any ideas?
Mike


Sent from my iPhone using Tapatalk

 

[93max]

Reading this with interest. I have an 89 max with 23000 on the clock. Can’t seem to solve the erratic tick over when warm. Ht coils are changed, balanced carbs but still get this problem when warm. Starts easy if it should stall goes like stink. Any ideas?
Mike


Sent from my iPhone using Tapatalk

Have you looked over the starter slow crank when warm thread yet? I'd look there 1st before diving into the pick ups.
On my SXF 450 the PU was 50% of the problem. 25% was the TPS had to be EXACTLY in the right spot and the other 25% was the correct starting procedure.
That bike would not start with choke!
2 twists of the throttle and presto it fired rt up.
You had to keep it running tho till luke warm.
If it was outside in <30* weather DON'T EVEN BOTHER using the E button unless a car was hooked up to it for the 1st start of the day.
I sold it this summer with all the issues resolved but it drove me freaking nuts learning!:biglaugh: