New Member - 1974 Super Rat (98) Ran for 30 min and then NO SPARK . . .

[mpaar]

Group,

My daughter and I, resurrected a 1974 Super Rat (98), that had been sitting in a open shed for 22 years. We got it running, and drove it for about 30 minutes before it died. Now it has no spark.

Can I use a multimeter to test the Coil? The CDI unit? The Stator (Inner Rotor/CDI Magneto)?

According to the Wiring Schematic the wires are as listed below:

BK - black (Stop wire)
BK/W - black/white stripe (Ground wire)
BK/R - black/red stripe (Exiting wire)
R/W - red/white stripe (Pulse wire)
W/BU - white/blue stripe (Primary wire)

Does this forum have a test procedure? And specs for resistance values? And a source for parts?

Any help will be greatly appreciated.

Best Regards,
mike

[taber hodaka]

Just my guess. I would try a new plug, points and then the rest. Clarence

[Bullfrog]

Model 98 with CDI (no points). To my knowledge, Hodaka/PABATCO never did publish component specs for the CDI. Sooooo . . . when checking/searching for spark . . .
1) Disconnect kill switch (in case it has a fault)
2) Replace spark plug
3) Check spark plug cap and plug wire for faults
4) Check spark coil for primary winding continuity and resistance (should be fairly low resistance), Check secondary winding for continuity and resistance (resistance should be many times higher than primary winding)
5) Check continuity and resistance of stator coil if possible. (I can't remember the unit well enough to know whether or not this can even be done.)
6) (and I know this was a phrase published back in the day) - substitute known good components into the system till the bad one is found.
Ed

[dirty_rat]

You might check to see if there are any test procedures listed for the 1977-1978 Honda CR 125, (check on a Honda site, etc) as it's ignition was very similar to the Hodaka's (I know some people have used both components and the whole ignition from the Honda on their Hodaka's).

Just a thought.

[Bullfrog]

A good thought!
Ed

[mpaar]

Group,

I found this 'Testing For No Spark' topic from 2019.

viewtopic.php?t=3655&sid=3a1f7b6c67ffb2 ... fc5d803da6

It seems very useful and shows a 2 D-Cell battery device that you can use to help in the diagnosis.

Plus I have two more questions using the Super Rat Wiring Schematic (98):
1. Is W/BU to Gnd the Primary?
2. Is the spark plug wire to Gnd the Secondary?

Best Regards,
mike

[mpaar]

group,

Oh, and I know that the Super Rat (98) does not have points, but the above 'Testing For No Spark' procedure still looks like a useful thing.

mike

[Bullfrog]

While I haven't used that technique (3V battery source attached to CDI) for testing . . . I have extreme doubts that it will be useful. A great method for point type ignitions . . . but probably useless on CDI.
Ed

[Bullfrog]

PS: . . . though it might be useful to test the ignition coil mounted under the tank (only). Maybe. Possibly.
Ed

[Dale]

Group,

I found this 'Testing For No Spark' topic from 2019.

viewtopic.php?t=3655&sid=3a1f7b6c67ffb2 ... fc5d803da6

It seems very useful and shows a 2 D-Cell battery device that you can use to help in the diagnosis.

Plus I have two more questions using the Super Rat Wiring Schematic (98):
1. Is W/BU to Gnd the Primary?
2. Is the spark plug wire to Gnd the Secondary?

Best Regards,
mike

Yes, to your questions on the primary and secondary of the coil. You can unplug your connector to isolate the coil from the CDI unit and then pulse the W/BU lead to the coil and generate spark at the plug.

[dirty_rat]

Plus I have two more questions using the Super Rat Wiring Schematic (98):
1. Is W/BU to Gnd the Primary? YES
2. Is the spark plug wire to Gnd the Secondary? YES

[Joe Ormonde]

It may not be your problem BUT check the crank key for the Rotor. I had that problem on my CR500 when the key sheared. It sure is nice when you have spare parts. The main problem we had back in the day was the Spark Plug cap. It had a aluminum pointed screw that would burn up. Your cap should be a better design. Joe

[mpaar]

All,

Right now it is running ok. It wants to stumble and then rev high as you move off of idle. It is difficult to transition smoothly to a moderate speed. It is also touchy to ride a low to mid throttle openings.

mike

[dirty_rat]

Sounds like it could have an air leak. I would suggest that you do a leak down test on the engine (there are instructions on here somewhere if you search, there might also be instructions at hodaka-parts.com). If it is, and it's not corrected, it can quickly lead to a blown engine.

[dirty_rat]

Check out this post for information on how to build/use a leak down tester.

viewtopic.php?p=36722#p36722

At hodaka-parts.com there are a couple of items to watch/read. The first is under the "Library" section, in videos. There is a video on how to perform a leak down test. Then in Library-Articles, there is an article from Dirt Bike magazine on "Tracking the wild air leak".