"Green Monster" + Points = Stupid?

[UncleBuck]

I know I have to replace the LHS coil on my '78 Special, but I'm torn on if this is the right time to do the Pamco upgrade while I'm mucking about with the ignition. Cash being king, after all.

If I were to buy any of the high output coils from Mike's how stupid would I be to run it using the stock points?

Also, the LHS coil is cracked, the terminal for the plug wire is nasty with rust, and it gets hotter than all hell when I run the starter. It's clearly pooched. Is there anything I should check into that would fry one coil (but not the other) before I sink some cash into a new coil only to fry that in short order?

 

[pamcopete]

UncleBuck,

The green single output coils are 3.3 Ohms vs the usual 4.9 for points, so they will draw more current and that means a shorter life for the points. Also, they are unsuitable for future upgrade to a PAMCO unless you plan on doing a 277 conversion because the PAMCO uses just one dual output coil on the standard 360 engine.

If you are just trying to get through the riding season, then just buy the Part #17-6805 replacement coil for now and take another look next year.

 

[5twins]

So many people have done the Pamco upgrade that you should be able to get a good used stock coil cheap.

 

[Brian902]

I have 2 original 78 coils and live here in the Maritimes.

Do you want one?

Free, you pay the shipping.

Nothings free is it!

 

[5twins]

If you've found one rusty connection, no doubt there are more. Sounds like your wiring needs a good going over. That will ward off future problems. If that's too much trouble then be prepared for numerous electrical problems, pretty much one right after another. And grab your wallet, you'll need it to replace all those burned out electrical parts, lol.

 

[XSLeo]

You can use a dual output coil by connecting the points wires together and then hooking them to the coil.
Just use a coil with the right ohm primary or add a ballast resister inline with the coil.
I think RG did this until he upgraded his points to a Pamco.
I did this on my 75 till I did the Pamco upgrade.
By doing the coil upgrade now, you can just add the basic Pamco later.
Harley used such a coil for years. They call them dual fire. They used a 4 to 5 ohm coil that in it's newest rendition has a 30k + output and will work without the ballast resister and work with the Pamco. One such as Ebay item # 251304164581 It says electronic ignition but they used a 4ohm coil for the points and early electronic ignitions.
Search Harley coil then sort by price + shipping low to high then scroll down. Most coils used from he mid 80's up used a low ohm coil for the electronic ignitions. There are some used coil that may work but the sellers don't list the primary ohms. You can contact them and ask for the ohms.
Some have found that Honda used a similar coil and can be found for around $10.
Leo

 

[UncleBuck]

pamcopete: I was thinking about doing something like XSLeo describes. You make an excellent point about the lowered life. I think I'll follow (most of) your advice and grab Brian902's almost freebies. My concern is mainly getting things on the road.

5twins: Yea, you're on the money with the electrical. There are more than a few "after-market" wires on there. Along with a yard or twenty of electrical tape and some corrugated plastic flex tube for style. The PO had some flair; the fuel lines and oil lines have been wrapped in braided stainless and held in place with zip ties.

Brian902: You're awesome. See your PMs.

XSLeo: I'll have to hunt around eBay for those, as well as the few sources I know of for old bike parts.

General feedback: thanks for confirming just how great resources like this board are. I love working on this bike, but every now and again, my engineering background throws a wrench in demanding if "I'm sure this will work." Also, I live in fear of letting out the magic smoke. I keep asking PCB suppliers if they can sell me a can, but they won't...

 

[pamcopete]

UncleBuck,

OK. If you do XSLeos idea, you will only need one of the condensers. Later, when you switch to a PAMCO, remove that one condenser as well as the ballast resistor.

One of the advantages to an electronic ignition is the ability to use low Ohm coils, like 2.5 Ohms, so don't short change yourself now if you plan on a PAMCO in the future.

 

[UncleBuck]

So, I've now got Brian902's coil (again, thanks kindly).

My good coil is a Hitachi CM11-54.

My bad coil is a Hitachi CM11-55.

Brian902's coil is a Hitachi CM11-50.

I'm going to take the coils to work tomorrow to check them out on a Fluke meter, as opposed to my POS Motomaster meter.

Any suggestions on why all the part numbers are different?

 

[Brian902]

The two I had measured 8.4K / 4.3 and 8.3K / 4.1 on my MasterCraft meter. Interested to see what you get.

And it's from a 1978 XS650 SE.

 

[UncleBuck]

Brian: The Fluke meter at work says I've got your 8.4k / 4.3. My good coil is 8.2k / 3.7. My bad coil is 17 M / 4.

So, as the man says; "There's yer problem!"

 

[5twins]

Yamaha used that same coil for over 10 years on various models .....

http://www.boats.net/parts/detail/yamaha/Y-254-82310-60-00.html

It wouldn't surprise me if the numbers on the side were just different production versions or runs. The ones on my '78 Standard were 11-50s like Brian's.