#4 not firing

Information and questions on GL1000 Goldwings (1975-1979)
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Posts: 1
Joined: Wed Dec 30, 2015 10:52 pm
Location: Tennessee
Motorcycle: 1975 GL1000

#4 not firing

Post by btg »

Hello all, this is new to me. I'm not a mechanic. I have a 1975 GL1000 that #4 is not firing. Here is what I have done so far: when I purchased the bike I had the carbs cleaned and synced. Changed plugs. I rode a couple times, but if I hit big dip or bump in the road I would lose power. I could mess with the plug wires let it sit and it would regain power a few times. Currently it is down power so I changed igition coils, plugs look good. Still no power and down #4 with no fire. Suggestions would be appreciated.
Reminder, I'm not a mechanic, I'm a new rider so please keep the lingo simple.


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Motorcycle: 1999 gl1500 se

Re: #4 not firing

Post by wingman12 »

Good evening big, I wish to welcome you to the worlds best GW site for information and friendly advise and assistance. There are many reasons for your problem. I am also no mechanic, just a back yard mechanic and learn a lot from this site. More experienced persons will add their comments and suggested solutions after me. Have you ran the engine in idle and pulled the plug wires to verify no fire #4? Is the plug fouled and oil soaked? Did you remove the plug and connect to the plug cap, ground to engine, crank engine to see if you have spark? It is possible that who ever rebuild your carbs missed cleaning a jet cleaned properly, could be a stuck slide in the carb? Was the timing belts changed and retimed and valves adjusted before the carbs were synced? Hopefully some of these ideas will help. :D :D
Posts: 219
Joined: Tue Mar 09, 2010 12:53 pm
Location: La Crosse, WI
Motorcycle: 1977 GL1000

Re: #4 not firing

Post by sfruechte »

The weak link in the plug wires is probably the cap, which screws into the plug wires. I've also had a plug cap that did not grip the spark plug tightly.
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Fred Camper
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Location: Metro Detroit, MI
Motorcycle: 1977 GL1000, 1976 LTD GL1000

Re: #4 not firing

Post by Fred Camper »

This is a waste spark ignition system, so two plugs always fire at once. One and two fire at the same time, and 3 and 4 also. So if you hook up the wire for plug 3 to plug 4, it will let you know if it is the cylinder or wiring.

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Joined: Mon Aug 18, 2014 11:47 pm
Location: St. Andrews, Manitoba
Motorcycle: 1977 Gl1000

Re: #4 not firing

Post by Liberaci »

I had the same issue with #3. (right front cylinder?)

I found that this was a timing issue. You will want to read the split timing article on Randakk"s site.

For me, I found that I was using alot of fuel, and the engine had little power under load. I also thought that It would burn more oil.

I used a laser temp pointer gage, and found that #3 was much colder then the other three cylinders. Checked the plug and it was wet.

When I played around with the timing, this fixed this issue for me. It turned the bike into a rocket. Lots of power!

(I also replaced timing belts, cleaned carbs, replaced the spark plug caps, checked Valve clearance)

If anyone has further info regarding timing issues affecting one cylinder I would like to hear your thoughts. Timing these engines with the split the difference technique is a bit confusing. Im a beginner at this, so my comments may be incorrect.

I am also thinking of updating to electronic ignition, as I seem to have pitted points all the time. Forever needing to file them clean.

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