cylinder not firing


Information and questions on GL1000 Goldwings (1975-1979)
  • Sponsored Links
MrHill06
Posts: 9
Joined: Fri May 01, 2015 11:01 pm
Location: broken arrow oklahome
Motorcycle: 79 gl1000

cylinder not firing

Postby MrHill06 » Fri Aug 14, 2015 10:24 am



Ok guys I'm at a loss here. The other day I had a buddy over and he said my bike wasn't running as good as it could. I thought it was running great considering I just rebuilt the carbs and it ran 100% better than it did when I got it. Anyways we let the bike run and started pulling plug wires one at a time and when we pulled the last one the idle didn't change. So first thing we did was check for spark. We had spark. Next we checked compression. Had good compression. And we could smell fuel on the plug. So I'm assuming we are getting some sort of fuel so what could be the problem? Ideas what to do next? Any help is appreciated!

It's a 79 gl1000

Thanks



User avatar
virgilmobile
Posts: 7663
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: cylinder not firing

Postby virgilmobile » Fri Aug 14, 2015 6:19 pm

First,swap out the spark plug...start it from dead cold...idle ONLY for 8 seconds... do not Rev the engine...shut it down and lightly tap each header...
cold is a non running cylinder...
Next..does it have points or electronic ignition...A poor spark can fire one side and not the other...Is it a good hot spark?
What does the plug look like compared to the other ones.?Does it look the same.?...Is the compression within 5psi of the other ones.?
Is the ignition timing exactly right.?How bout the valve lash and cam timing marks...
Sorry...so many things to check..

MrHill06
Posts: 9
Joined: Fri May 01, 2015 11:01 pm
Location: broken arrow oklahome
Motorcycle: 79 gl1000

Re: cylinder not firing

Postby MrHill06 » Fri Aug 14, 2015 7:57 pm

Ok so I've done the checking of the headers it's the back cylinder on the left side of the bike (if you sitting on it) that's cold. Spark at the plug (pulled it out and set it on the block while starting) good consistent white/bluish spark. And all cylinders are within 4 psi of each other. Plug is slightly wet with. Nothing terrible but definitely unburned fuel. Bike has a elec. Ignition and had been static timed.

Thanks again for the help!

User avatar
virgilmobile
Posts: 7663
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: cylinder not firing

Postby virgilmobile » Fri Aug 14, 2015 9:32 pm

With what you indicate,you may simply need to replace the plug.I do suggest you increase the gap to 0.035".
Electronic ignition ya know compared to points has a different gap...
Don't use Champion or Delco..Stay with OEM...NGK d8..
I also recommend pulling all 4 plugs out,turn off the fuel,kill the ignition and crank the engine a couple of times to dry out the cylinders.
Scrutinize the plug caps too...they are resistance type and don't last forever...same as the wire..even tho you see a good spark,it can
go pu pu under pressure and demand..
When you finished the carb service,did you sync the carbs....then do the idle down adjustment on the idle valves.?
One last thing....with my 1000,I had issues with the old black composition floats...They were properly set but I found that the entire bike would soon start to run rich...eventually it would puke out and foul the plugs...I did find that the floats would absorb gas and sink in the fuel in just half a day...this raised the fuel level in my carbs by,at least 25%.
I ended up dipping all 4 of them a few times in Polyurethane to seal them...I don't know if this will hold up with the ethanol fuel tho...Never tried.
Fuel level is critical...actually within 1mm and steady..any more and that cylinder runs rich.

MrHill06
Posts: 9
Joined: Fri May 01, 2015 11:01 pm
Location: broken arrow oklahome
Motorcycle: 79 gl1000

Re: cylinder not firing

Postby MrHill06 » Sun Aug 16, 2015 5:58 pm

I did sync the carbs and they were pretty close to one another but what was the other thing the idle down adjustment? I think this is the first time I've ever heard of that. Thanks for all the help

User avatar
virgilmobile
Posts: 7663
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: cylinder not firing

Postby virgilmobile » Sun Aug 16, 2015 8:05 pm

This is a reference to fine tuning the carbs idle circuit...Sometimes called "idle drop procedure"
The idle mixture screw is preset then each one is turned out until the engine drops about 50 rpm then turned back in just in till the rpm picks back up...This sets the idle mixture for each carb..
They can be arbitrarily set at the books starting point and be close enough...however there's the chance one or more may be running rich or lean...The book has the starting point...it varies for each model...I think the 1100 starts at 3 turns out from bottom..
Close on the sync is just that...close....Same thing for the timing...close or exactly right....
If you get everything close....you end up with a engine that runs.....well...close...

MrHill06
Posts: 9
Joined: Fri May 01, 2015 11:01 pm
Location: broken arrow oklahome
Motorcycle: 79 gl1000

Re: cylinder not firing

Postby MrHill06 » Sun Aug 16, 2015 9:31 pm

Nice I will definitely give that a shot. I also ordered new ngk caps and plugs just to be on the safe side!

User avatar
WingAdmin
Site Admin
Posts: 17050
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: cylinder not firing

Postby WingAdmin » Mon Aug 17, 2015 2:47 pm

What about the exhaust? Compare the temperature of the exhaust of that one cylinder to the other three. Start when it's cold, and use your hands, to see how quickly they warm up in comparison to one another. Test both at idle and at higher RPM.

MrHill06
Posts: 9
Joined: Fri May 01, 2015 11:01 pm
Location: broken arrow oklahome
Motorcycle: 79 gl1000

Re: cylinder not firing

Postby MrHill06 » Mon Aug 17, 2015 2:55 pm

The exhaust at that one cylinder is much cooler than the rest




Return to “GL1000 Information & Questions”




Who is online

Users browsing this forum: No registered users and 1 guest