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Discussion Starter · #1 ·
Here's a dumb question:

Do 1978 (6 volt) CM185s start only by kick or with the electric starter?

I busted out my multimeter and have tested my electric and traced from the battery to the end of the line and I get good juice throughout. I also get the starter to run and run. I have juice at the points, and I cleaned up the spark plugs so they aren't coated in ancient carbon anymore. I smell fuel when I attempt to get the engine to go and also have taken the air filter out just to ensure I am getting air into the mix. All parts are original from what I can tell.

But the engine just won't rumble on its own. No life at all using the electric start. Should I be kicking this thing or only using electric start? Is there someone I need to pay off to get this thing to go? Any ideas?

Signed,

Frustrated Noob
 

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I have a 1978 CM185T and it will start both with the kick start and the electric starter. These 6v systems are a little temperamental and really like a good fully charged battery, but it should be able to start either way.
You might have to go through the drill. Check compression, spark, timing, fuel/air mixture. One or more of these are wrong if it wont start.

Dave
 

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First thing to check is battery power to the coil......(Is your "kill" switch turned to "RUN"?)
IF yes, do the plugs spark? (Note that BOTH plugs must be grounded for either to spark)
IF Yes again, and still won't run, phone me....540-525-5199.....
 

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Discussion Starter · #4 ·
awesome - thanks!

i'm going to do a compression test tonight. i'll double check the plugs. the kill switch was removed - which i'm going to have to fix after i get the thing to start. the line is soldered closed so power looks to be going to the right place.

i checked the bulbs to make sure that someone didn't put 12v bulbs in the mix and everything looks good.

i'll post up how the compression test goes and go from there.
 

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Discussion Starter · #5 · (Edited)
I just did my compression test and it came in at 120 PSI. This is my first compression test ever. I didn't "crank" the fitting in the spark plug hole but it was hand tight. Figure that should give a good enough reading. The manual says 170. Will the engine attempt to fire even with starting fluid with PSI that low or is that not enough PSI to get some sign of life?

A rerun of the spark test is up next.
 

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Discussion Starter · #7 ·
So it looks like I have a short in the coil. I have a spark, but it's really inconsistent. My best guess is I get spark when there is enough juice to get an arc across the short.

I think it's the coil. I did some continuity testing and when I pop the multimeter positive end in one of the plug wires and the negative in the other, I get nothing. But when I do the same thing right off the coil, things are A-OK. I'll post some pics to show what I mean.
 

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Discussion Starter · #8 ·
So in the first pic, when I disconnected these and tested continuity, all is well.
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image.jpeg

But when tested in these, it's no good:
image.jpeg
 

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Intermittent spark can be anything from weak battery to poor connections, to corrosion within the plug caps resistors, to fouled or dirty points.......
Call me when at bike with meter..... 540-525-5199.....

Pics seem to indicat coil primary is fine (and points, etc.... So it's likely the secondary or caps.....
 

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Discussion Starter · #10 · (Edited)
I'll give you a buzz tomorrow. I had the battery at full charge, checked the gaps on the points and plugs. I think it's the secondary. Didn't think about caps.

Turns out my neighbor has plug wire. It's good to have neighbors with bikes. I'm gonna bypass the old wires and see what happens. I'll call if I am still stumped.
 

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Pull caps off (they "unscrew"), and read plug-wire to plug-wire..... 20K Ohm scale......
There is NO connection from secondary to primary as is usual in "automotive" type coils, these are actually transformers.....
Also check that NEITHER primary NOR secondary show continuity to the metal core strips (ground) (unplugged from points of course)
 

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Discussion Starter · #12 ·
Pull caps off (they "unscrew"), and read plug-wire to plug-wire..... 20K Ohm scale......
There is NO connection from secondary to primary as is usual in "automotive" type coils, these are actually transformers.....
Also check that NEITHER primary NOR secondary show continuity to the metal core strips (ground) (unplugged from points of course)
Did what you said and here are the results.

Got it. I think. Secondary. Wires are good. Caps are good. Wire with cap on left, bare wire on right, good. Wire with cap on left and right, no good. Right cap to wire connection flickers a connection in the beginning, then it goes away. So it's the cap to wire. New plug wires and caps should do it. I think.

Pics: (sorry, the pics came in upside down)

This shows continuity with left cap on, right cap off.
image.jpeg

This shows both caps on. No flow through:
image.jpeg

The interesting thing is I get a quick connection, then it dies away. I recorded a video of that. It's just on, then off. If I wiggle nothing changes. Remove and retouch, flicks again. But the cap is good. So the cap to wire connection must be bunk. Here's the cap continuity:
image.jpeg

I'm going to replace the plug wires and see what happens. Any bad things I can get tripped up with doing that? Will any plug wire work?
 

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Cut 1/4" to 3/8 " off the end of the right wire....rescrew cap on and recheck,,,, I'll bet it's good.....

Phone if instructions not clear.......540-525-5199....Steve
 

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Discussion Starter · #14 ·
so i snipped about 3/8" off, and i still have the same problem. very weird. gonna snip again and remeasure until i can't. are replacing these wires a pain?
 

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Discussion Starter · #15 ·
Same issue. I don't get it. Wires are good. Caps are good. Wires and caps together, I get a quick connection, then it stops. Steve expect a call this weekend!
 

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You need to test the coil for spark off the bike....Until we are SURE it actually fires every time, further diagnostics are at a standstill....
 
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