Big bang while trying to start.
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Big bang while trying to start.
I have a 76 LTD that I just got a week or two ago. I have driven it 50 to 75 miles without issues. I tried to start it last night without luck. When I shut off the key it back fired loud. I tired again and it did the same think. This bike has an electronic ignition. This is my first bike so I have little knowledge of what to look for. I have restored several old trucks. Based on that it is my thought that it is loading up with fuel and only getting spark when I tried to shut off the key. Any help would be appreciated.
- rcmatt007
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Re: Big bang while trying to start.
First of all. Have you changed the timing belts?
-Rodger-
all it takes for evil to prosper is the want of a few good men to do nothing-Edmund Burke
The question is not how much time do you have, it is what you do with the time that you have Gandalf
"One of the greatest dignities of humankind is that each successive generation is invested in the welfare of each new generation." Fred Rodgers
"it takes 10,000 hours to become an expert" ancient saying
78 constantly modified/customized since 1978, BOTM June 2015 de-evolving this very moment viewtopic.php?f=30&t=65511
76 Ltd "cookies bike" ALMOST DONE
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'86 1200 (Beth's)(FOR SALE) with motorvation sidecar (sidecar sold) , July 2017 BOTM
'17 HD Road king and 08 HD Heritage softail (Beth's) (FOR SALE). I guess you can say we have MBS
all it takes for evil to prosper is the want of a few good men to do nothing-Edmund Burke
The question is not how much time do you have, it is what you do with the time that you have Gandalf
"One of the greatest dignities of humankind is that each successive generation is invested in the welfare of each new generation." Fred Rodgers
"it takes 10,000 hours to become an expert" ancient saying
78 constantly modified/customized since 1978, BOTM June 2015 de-evolving this very moment viewtopic.php?f=30&t=65511
76 Ltd "cookies bike" ALMOST DONE
79 project, finished, FOR SALE
'86 1200 (Beth's)(FOR SALE) with motorvation sidecar (sidecar sold) , July 2017 BOTM
'17 HD Road king and 08 HD Heritage softail (Beth's) (FOR SALE). I guess you can say we have MBS
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Re: Big bang while trying to start.
I have not. It was changed when the bike was rebuild. It should be almost new.
- dontwantapickle
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Re: Big bang while trying to start.
I have had that happen on a Norton I had with an electronic ignition.
It turned out to be a bad key switch that only worked when in the perfect position or made contact when the key was turned.
It may not be your issue, but it might be worth checking out.
It turned out to be a bad key switch that only worked when in the perfect position or made contact when the key was turned.
It may not be your issue, but it might be worth checking out.
- Sagebrush
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Re: Big bang while trying to start.
Seems to me I remember something about a low voltage situation where the coils didn't have enough juice to fire while the starter was turning over but just as you released the starter button removing the starter amperage the coil fired one time and started the bike. Seems to me it was a classic symptom on a 1500 of a weakening battery. I'm not very clear on what the final cause was but I would check for spark while turning the engine over to see if it there our just too weak to fire.
Dean Spalding
Raleigh, NC
"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe." - Albert Einstein
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Raleigh, NC
"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe." - Albert Einstein
'82 Yellow GL1100
'81 Blue GL1100
My Gallery
My 1100 Build Thread
- ericheath
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Re: Big bang while trying to start.
My 77 will kick back when I turn the key off sometimes, but not a Big Bang, and not when just releasing the starter button. The motor is dead still when switched off. It has Dyna Ignition.
Looking forward to theories.
I have wondered about the Hall effect of the Dyna triggering a signal to a coil as a result of the power drop as the key is switched off. The bike is supposed to fire ahead of TDC and with the piston stopped ahead of TDC, it would have to backfire.
The loud bangs could be from the waste spark touching off unburnt fuel in the opposite cylinder on the exhaust stroke.
Looking forward to theories.
I have wondered about the Hall effect of the Dyna triggering a signal to a coil as a result of the power drop as the key is switched off. The bike is supposed to fire ahead of TDC and with the piston stopped ahead of TDC, it would have to backfire.
The loud bangs could be from the waste spark touching off unburnt fuel in the opposite cylinder on the exhaust stroke.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
- robin1731
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Re: Big bang while trying to start.
First step. Verify if you have spark or not while cranking the engine. Pull all the plug. Place one plug in a plug wire and ground it to the engine. Crank engine over. You should have spark. And yes, installing just one plug will give you spark. You do not need two plugs installed to check spark with a Dyna.K9Sicem wrote:snip...…... thought that it is loading up with fuel and only getting spark when I tried to shut off the key.
Actually do this first. Before doing that turn the engine over with the starter with the run switch in the off position. Just to make sure there is no fuel in the cylinders. Have the fuel petcock turned off too.
.
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
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Re: Big bang while trying to start.
I took the plugs out and checked for spark. No spark while turn over the engine, but after I shut off the key I got one spark. I'm think the bang is coming from the burn off of unburnt fuel. How do I check the switch?
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Re: Big bang while trying to start.
Do you know if it ever ran with the Dyna? This is exactly what a stock ignition does if the ballast resistor gets unplugged. Some Dynas bypass the resistor, I think, but do you know if it was installed correctly?
- robin1731
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Re: Big bang while trying to start.
Shadowjack wrote:Do you know if it ever ran with the Dyna? This is exactly what a stock ignition does if the ballast resistor gets unplugged. Some Dynas bypass the resistor, I think, but do you know if it was installed correctly?
Depending on how it was wired though it should still have spark while cranking. But that is a good thing to check.
And yes, the ballast resistor should be removed if using both Dyna ignition and coils. But if you are still using the stock coils you still need the resistor. A new one comes with the Dyna.
.
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
- gltriker
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Re: Big bang while trying to start.
As this Topic progresses, there are quite a few mentions of Dyna.K9Sicem wrote:I have a 76 LTD that I just got a week or two ago. I have driven it 50 to 75 miles without issues. I tried to start it last night without luck. When I shut off the key it back fired loud. I tired again and it did the same think. This bike has an electronic ignition. This is my first bike so I have little knowledge of what to look for. I have restored several old trucks. Based on that it is my thought that it is loading up with fuel and only getting spark when I tried to shut off the key. Any help would be appreciated.
Has this LTD's 'electronic ignition' actually been visually identified as a Dyna unit?
Cliff (74yrs )
Keep your eyes and ears open and you'll learn something new, everyday.
New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
"Can't see the paint when your looking thru the handlebars..........." -Oldewing
"I'd rather Ride than Shine" -RAT Me Too!!
Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
Keep your eyes and ears open and you'll learn something new, everyday.
New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
"Can't see the paint when your looking thru the handlebars..........." -Oldewing
"I'd rather Ride than Shine" -RAT Me Too!!
Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
- gltriker
- Honored Life Member
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- Joined: Fri Sep 24, 2010 9:11 pm
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Re: Big bang while trying to start.
Two timing belts. Not just a single, It .K9Sicem wrote:I have not. It was changed when the bike was rebuild. It should be almost new.
It's a best practice to remove both timing belts' covers, now, and check for correct camshaft pulleys' static timing alignments.
Timing belts are very inexpensive.
See this Timing Belt Replacement tutorial from NGW Club's Shop Talk.
https://www.ngwclub.com/forum/viewtopic.php?t=3544
Cliff (74yrs )
Keep your eyes and ears open and you'll learn something new, everyday.
New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
"Can't see the paint when your looking thru the handlebars..........." -Oldewing
"I'd rather Ride than Shine" -RAT Me Too!!
Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
Keep your eyes and ears open and you'll learn something new, everyday.
New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
"Can't see the paint when your looking thru the handlebars..........." -Oldewing
"I'd rather Ride than Shine" -RAT Me Too!!
Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
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- Tin Member
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Re: Big bang while trying to start.
Both timing belts are good. Yes, it is a Dyna unit. Ran fine. Next night I wanted to ride and that is when it would not start. I checked for spark. Will not spark while turning over. It will give off one spark when I shut off the key. Battery is near new and has good voltage.
- robin1731
- Membership Admin
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- Joined: Mon May 29, 2006 8:31 am
- Location: Decatur, Indiana
Re: Big bang while trying to start.
Have you done any of the suggested tests/procedures/diagnostics?
.
.
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder
- ericheath
- Honored Life Member
- Posts: 9581
- Joined: Wed Jul 29, 2009 11:20 am
- Location: Winnipeg, Manituba
Re: Big bang while trying to start.
Could be a worn ignition switch. The one of mine that exhibits this had a bad switch and I pulled it apart and tightened up the rivets inside.
Have you probed the wires at the Dyna to see if they are getting power with the switch on?
Have you probed the wires at the Dyna to see if they are getting power with the switch on?
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
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