gs750 E? LN? EN? igntion coil mounting

[jgomes]

Hi,

I am replacing my ignition coils on my supposedly 1979 gs750. I'm not sure if it's an E/LN or anything like that, but I bought some NOS ignition coils for a 1979 gs750 LN and the mounting wasn't quite right. Is there a frame difference between the different models or years ('78, '79)?

I also wasn't quite sure if NOS meant anything specific. I was thinking it was a brand.

The ignition coil I pulled out says 7Q (which I'm still not sure what that means) 12V and there is maybe a part number: 029700. When I looked up the part number coils for a '78 gs750 came up.

The mounting distance between the center of each hole is about 4in.

Sorry, for all the questions I'm new to this and very frustrated! Thanks!

The Ebay ignition coils I bought were-> (http://www.ebay.com/itm/140725998003...9#ht_500wt_922)

[tom203]

The coils on my 650 have mounting bolt center to center of about 3 5/8 inch. Some 850 coils that I have have center to center of about 4 inch. The 650 coils have spade connectors- 850s have molded in wires.
NOS = new old stock
Some PO might have switch things.

[jgomes]

The ignition coils I bought off of ebay had a mounting distance of a bout 3 5/8. Hmmm. They definitely aren't spade connectors the are the molded wires with the boots. Would I cause my self trouble with putting a 850 coil on a 750? Also do you have any clue about the 7Q that goes along with the voltage? I've seen some others with different letters and numbers. Thanks for the bit of info

[tom203]

I don't know what those numbers mean. Measure the resistance- maybe 4 to 5 ohm on primary side and about 30,000 on secondary side (plug cap to plug cap). Are your old coils bad ? - the originals seem very durable.
I'd bet the 850 coil would be fine- the ignition systems are similar. My understanding was that points system had slightly higher ohm reading on primary side.

[jgomes]

Next time I'm at the farm working on the bike I'll measure the resistance. I THINK the coils are bad. I've been having a lot of trouble keeping the idle speed up so I adjusted the idle screw but the idle kept dropping at the end I had the idle screw cranked really high so next time I started it The rpms shot up. I think I still have the issue when I bring the clutch all the way in it essentially dies. I've also had problems with it hitting about 5k rpm and not going any higher and just kinda chugging right at 5K. A lot of troubles.

[tom203]

None of that sounds like coil problems to me; you should start a new post in Carb, fuel...forum. Before the farm, follow the link to Basscliff's site for a zoo of troubleshooting info.

[jgomes]

My friend discovered that my bike is a gs750 L so at least there is a little progress and It was suggested that I get ACCEL 140404 Universal Super Coil Kit. I'll be sure to check out the carbs/fuel forum section. I agree I also don't think it seems like a coil problem but I'm a newbie. Some of my friends were pretty inclined say that it was though. I know the carbs were cleaned out before I got it about a year ago. Thanks for your help.

[tom203]

Carbs cleaned a year ago,OK, but has bike sat for a while waiting for you? This ethanol fuel is nasty when it hangs around carbs- often causes the very problems you seem to be having, i.e. unsteady idle, poor power, etc. Take advantage of Basscliff's site , before you spend money on anything super.