'85 Maxim X (700) CDI

Hi folks,

First, what is a CDI?

Second, what CDI's from other bikes would be compatible with the CDI of a 700 Maxim X from '85?

Thanks,

 

CDI = Capacitive Discharge Ignition.

Our bikes use TCI, or Transistor Controlled Ignition. Two completely different animals, apparently, as one can see here.

As for your original question, I don't know what, if any, other TCI modules would be compatible with the X, but hey... we learned something today, right?

 

Great article. Thanks! After posting I kind of concluded doing further reading that what was being called the CDI had to be the TCI as the manual doesn't even list anything about a CDI and one search result seemed to use the terms interchangeably. This article makes it much clearer showing the difference in the two.

Now if I can just find out if there is any compatibility with other models ...

 

Is yors bad?

 

You have to define "compatibility".........there are probably some other units that will fit and plug into the harness, and probably even allow the bike to operate, but the advance curves, etc. for the 700-X TCI is going to be different than any others (otherwise, the other bike TCI unit would carry the same factory part number). The question is.....how much different are those perhaps-compatible-other TCI units (I don't have the slightest idea whether such anmals exist, or if they do, what any differences may be). And even if they are somewhat "the same" in terms of advance curves, how does that difference translate into real-world performance on an X? Are the pick-up coil impedances the same or tolerant of each other? Coil primary resistances? Etc.

You are blazing the path where no mere mortals have gone before. Good luck with your mission Jim. Should you fail, the secretary will disavow any knowledge of your task. And this message will self-destruct in 5 seconds.........


Here is the correct one for an X:

HCP417
OEM TCI Ignitor Unit
1AA-82305-10-00
large golden/yellow label reads:
IC IGNITOR
TID14-35
1AA-10 (date code)
Hitachi, Ltd. Tokyo Japan
NOTE: this TCI unit has a different size case and orientation than all others XJ-series TCI units.

Fits:
700 all X models
750 all X models

 

It was "diagnosed" by someone as being bad - a bike shop - but, the fact that there is no way to do a fault diagnosis without opening it and manually inspecting the board with magnification and circuit testing has me suspect. They certainly didn't swap a known good one in to test (given their availability), and there are other problems as well that are not associated with the TCI. Additionally, the shop told the PO that he needed a new CDI rather than a TCI. I would certainly expect a shop that has done that sort of work on the bike to know the difference and that it doesn't have a CDI ... In the meantime, I am trying to explore to find out if there is something I can swap in to at least test.

A quick search of google showed me two places listing the above TCI (thanks Chacal). One wants $400 and the other just a bit over $200. I suppose it is worth it if it gets the bike going, but at the same time that's a great deal to invest if you aren't *certain* that yours is bad.

 

there is a post somewhere on here from not too long ago where an X owner found a different tci unit in his bike. It wasn't more than a month but I don't remember who. I believe he said the bike ran with the other tci in it. Even if it isn't the "proper" one if you could find one of hte types he had in his for a cheap price it could at least tell you if you are on the right track. I assume the X does not run at all right now correct? But there are thousands of reasons that could be. One would assume if you tested for spark and had spark at all cylinders that the tci is working somewhat.

 

My opinion is you should find a running X and swap the TCI to test it.

If his bike runs with your TCI....then it's not the problem.
There's no way I would drop that kind of $ when the shop didn't even know what they were looking at.

 

A known working TCI would be ideal, but I'd have to find one to do that. Any volunteers <grin>

85MaximXX, I tried looking for that thread, but I couldn't find it. Can you remember any details to help me search?

I am not at all certain that it is the TCI, just that the shop said the CDI which it doesn't have ... I won't be able to work on it until Sat or Sun.

 

From what I understand, it cannot be an issue with the TCI, which is what I expected since the shop didn't know the difference between a CDI and a TCI;. When I picked the bike up on Sat, the PO was able to start it, but it wouldn't keep running for long and once stopped it would not restart for a while. If there was a TCI problem, it wouldn't start at all, right?

No air box, no filters, exposed carb intaks ...

Previously had pods, but no idea if properly jetted or synced.

I have found a number of electrical irregularities, starting with the coils hanging loose on each side of the bikes, obvious cable modifications, etc. Hopefully it won't be too hard to track down all the alterations.

Does anyone have an idea as to how to calculate how much diameter restriction there should be at the air intake port of the carb in order to reduce the air flow on pods down to what it should be for a normal airbox and path?

I am thinking I should be able to make some discs the same size as the carb opening and make a hole in it to allow just the proper amount of air from the pod. I lack the knowledge as to how to calculate it though. I anticipate a "donut" disk with the right sized hole in the middle.

 

Knee-jerk reaction: sounds like fuel starvation. Something's preventing the bowls on the carbs from refilling. Lemme tell you about an incident I had.

Went to ride my X into work one day. With almost a full tank, I got a few miles down the road, then it started acting like it was running on empty. Pulled over, had a hell of a time starting. Once it did, the process repeated itself.

Long story short, the tank on the bike had been replaced by a PO; they moved the existing gas cap over. Problem was, the cap wasn't vented, and the tank they used required a vented cap. Fuel couldn't flow because of the vacuum developing inside the tank.

How to test: run the fuel hose from the tank to a gas can. Put the selector on PRI. With the cap closed, see if the fuel flow starts to slow down. If so, open the cap and see if the flow increases.

If this is the case, you can try running the bike on the center stand with the cap open just to see how long it'll go.