Weakish sparks

[BADABING]

Howdy,new to the forum,and hoping someone can point me in the right direction. Decided to take out my Gs 750 (77) for the first time after a few months of a lay up..Spluttered into life after a few attempts,but didnt want to know without full choke,with the odd burst of flame from the exhaust. Then is got weaker,****tered and died,and now wont fire up at all. Took of a lead or two,and although there is a spark,i consider it to be weak,when i replaced the cleaned up items,again no go.and plugs soaked. WHERE DO I START? Im thinking coils but been told they rarely fail. Your ideas gentlemen please.

[BassCliff]

Greetings and Salutations!!

Hi Mr. BADABING,

Weak spark? Check out the coil relay mod, maybe new plugs and plug caps. Also, clean the carbs the right way, service and seal the air intake system properly. Now let me say "Howdy" and give you some more information to get you started....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[chef1366]

What' the voltage at the battery?

[BassCliff]

What' the voltage at the battery?

Yeah, what he said. Go through "The Stator Papers" to check out your charging system. These bikes love clean electrical connections and grounds along the entire harness. A direct ground connection between the regulator/rectifier and the negative terminal of the battery is a good thing.


Thank you for your indulgence,

BassCliff

[BADABING]

What' the voltage at the battery?

New Today,motor spinning normally.

[Big T]

Now, now - whip out the VOM and test what the voltage is at the battery, coils and, dare I say, Points?? And tell us what those voltages are

If there's less than 10.5 V at the coils, you need the relay mod

Voltage drop comes from corroded wires and connectors

If you've still got points I'd start with new condensors (but if it was me I'd toss the points and install a Dyna)

[Larry D]

When was the last time the bike was ridden on a regular basis ? How did it run then ?

[BADABING]

When was the last time the bike was ridden on a regular basis ? How did it run then ?

It hasnt been started for several months.its farfrom standard,its bored out to 844 with a gsf front and rear end,one off alloy tank,none of which is relevant to the starting issue it dosent have an airbox,just bellmouths straight on to the carbs.im getting a spark on all four but it not strong enough to ignite and wets the plugs very easily,prior to the lay up it ran fine,just took a while to warm up.

[BADABING]

what is the relay mod ye all mention????????????

[BADABING]

I dont have access to all these fancy testers,this is Ireland man,where you still use a Rizla to set the points gap

[almarconi]

Measure voltage at the coils. Measure resistance both primary and secondary on both coils. Check plug wires and caps. Plugs clean and dry, fouled plugs won't fire. Check to make sure all your grounds are tight. All fuses intact.

Where was the bike stored? I would check for rodents and chewed wires if stored outdoors.

Do these basic tests and report back.

[almarconi]

I dont have access to all these fancy testers

Without a volt ohm meter it will be difficult to diagnose any electrical issues.

what is the relay mod ye all mention????????????

Do a search for coil mod on this forum.

[BassCliff]

what is the relay mod ye all mention????????????

Hi,

The coil relay modification is an electrical "enhancement" that overcomes the resistance of an old wiring harness (with all of its dirty, corroded connections and brittle wiring) and delivers a full 12 volts to the coils, ensuring a fat spark. I've collected a lot of information about this modification on my website.

Coil Relay Modification
(by Mr. oldryder and Mr. Matchless)

More On Coil Relay Modification

Even a cheap volt/ohm meter (or digital multimeter) will be very helpful in chasing down electrical gremlins.

Thank you for your indulgence,

BassCliff