spark boxes and pulse generators

[phishfood]

Hey all,
I have a 88 honda hurricane 600 that up until a few weeks ago ran fine. I get home, turn it off and the next day it wont start. The starter works, I can smell gas but it doesn't fire. I've been testing various aspects of the electrical system, changed the battery (it was weak under charge) and the spark plugs.

Now I've narrowed it down to the spark box or the pulse generator. One of the generators falls within speck 512 ohms(? upside-down Uish) but the other gives me 1.8m ohms.

Would one bad pulse generator (out of two) keep the engine from firing?

Any other thoughts or areas I can try? I was thinking of bringing the spark box in to get tested.

Thanks

[stoinkythepig]

One pickup coil would only keep 2 cylinders from firing, either 1 and 4, or 2 and 3. Did you check them all? Most bikes will start on 2 cylinders too, they'll run like crap though. If your bike has resistors in the plug caps, check those. They do fail and you can often get aftermarket plug caps from NGK pretty cheaply.

[phishfood]

I checked resistance at the plug caps and at the ignition coils for 1/4 and 2/3 and they came back with in spec.

Thanks for the info about the pulse generators. Its been an annoying process.

Also, when I pulled the plugs had more of a black carbon buildup which i took to be a weak ignition. Forgot to mention I changed out the air filter as well.

[Doc]

spark box?... Pulse generator?

[stoinkythepig]

spark box?... Pulse generator?

Electronic ignition module and pickup coil (or pulsing coil).

[Doc]

Electronic ignition module and pickup coil (or pulsing coil).

AHHH!!

[phishfood]

An update and a question

I got the bike to start last weekend, took the spark plug out of cylinder one and held it next to the engine while trying to start the bike to see if there was a spark - instead the engine started to come to life. I reinstalled the plug and the motor works again like a champ. Drove it all week without a problem.

After work yesterday, around 6, I go to start the bike and again the starter cranks over but the engine doesn't catch. Bump start it and comes right back to life. Leave it over night and it starts right up this morning.

I'm kinda at a lost what it might be doing and still rather not pay for a mechanic yet. Any ideas? thanks for the help thus far.

[schleppy]

Any of the ground wires thin or corroded?

[stoinkythepig]

Thinking weak battery or poor battery connection. I know it's a new battery, but, assuming there are no bad connections, perhaps the charging system is not working reliably, or you have a parasitic load. Bump start it again and test the voltage at the battery. Should be >14 volts with the engine running at 3000 RPM or more. You service manual will have more specific voltage/RPM requirements.

[phishfood]

thanks, I'll give the grounds another look and check the voltage.


I thought it also might be the connections - its the one area that I haven't cleaned yet - and do so last night. Used some dexoit d5 and find grit sand paper on the contacts and it looked much better when I was done.

We'll see if it gives me problems again. Now just need to flush the front brakes and probably change the pads and hopefully I'll be set.