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Discussion Starter · #1 ·
My daughter has had two sudden engine failures while riding. Starts right up again and runs fine. Anybody had similar problems? Haven't really spent much time trouble shooting. As long as it is running fine it is pretty hard to find a problem.
alex
 

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Alex, it is hard to say. But if it is running fine, then suddenly stops, I would first look at safety switches (neutral switch, kickstand switch). Of course, first check all connections first such as switch plugs, battery, etc.

another possibility, I had an electronic control module in a car that would quit suddenly when it got hot. Do our bikes have an ECM or anything like that?

How long is it running before it quits?
Dan
 

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Hi,

I have an 84 VT700c, they are fun to ride but have their moments when they can be frustrating.

The two things that cause an engine to stall are lack of fuel or lack of fire, a complete lack of fire for this engine is rare you usually loose one cylinder or the other not both, I doubt it is fuel related because once the carb's fuel bowls are dry it takes a lot of cranking to get them full again before the engine fires up again it doesn't just start right up again.

I would start with the electrical system, what both cylinders have in common is that the RUN/KILL switch supplies power to both ignition coils (they are both directly below the gas tank and in front of the carbs) and both ignition modules (they are both under the back seat).

The clam shell that the RUN/KILL switch is in comes apart fairly easy, the switch sometimes becomes oxidized and causes problems just like this one and needs to be cleaned out.

Does she have the 84 VT500c or the VT700c?


 

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Discussion Starter · #4 ·
Alex, it is hard to say. But if it is running fine, then suddenly stops, I would first look at safety switches (neutral switch, kickstand switch). Of course, first check all connections first such as switch plugs, battery, etc.

another possibility, I had an electronic control module in a car that would quit suddenly when it got hot. Do our bikes have an ECM or anything like that?

How long is it running before it quits?

Dan
I suspect electrical problem, I think I will bypass one switch at a time and monitor the result. The problem is that is has only happened twice. Once when she was on a relatively long trip and once on a very short trip. Both times it fired right up again. There is no ecm.
 

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Discussion Starter · #5 ·
Hi,

I have an 84 VT700c, they are fun to ride but have their moments when they can be frustrating.

The two things that cause an engine to stall are lack of fuel or lack of fire, a complete lack of fire for this engine is rare you usually loose one cylinder or the other not both, I doubt it is fuel related because once the carb's fuel bowls are dry it takes a lot of cranking to get them full again before the engine fires up again it doesn't just start right up again.

I would start with the electrical system, what both cylinders have in common is that the RUN/KILL switch supplies power to both ignition coils (they are both directly below the gas tank and in front of the carbs) and both ignition modules (they are both under the back seat).

The clam shell that the RUN/KILL switch is in comes apart fairly easy, the switch sometimes becomes oxidized and causes problems just like this one and needs to be cleaned out.

Does she have the 84 VT500c or the VT700c?


It is a 750, I think I will check out the kill switch first. It will likely take some time to solve unless I can find something obvious. It has only happened twice. But they occurrences were relatively close in time. It makes her a bit nervous to go very far from home.
alex
 

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Discussion Starter · #6 ·
Hi,

I have an 84 VT700c, they are fun to ride but have their moments when they can be frustrating.

The two things that cause an engine to stall are lack of fuel or lack of fire, a complete lack of fire for this engine is rare you usually loose one cylinder or the other not both, I doubt it is fuel related because once the carb's fuel bowls are dry it takes a lot of cranking to get them full again before the engine fires up again it doesn't just start right up again.

I would start with the electrical system, what both cylinders have in common is that the RUN/KILL switch supplies power to both ignition coils (they are both directly below the gas tank and in front of the carbs) and both ignition modules (they are both under the back seat).

The clam shell that the RUN/KILL switch is in comes apart fairly easy, the switch sometimes becomes oxidized and causes problems just like this one and needs to be cleaned out.

Does she have the 84 VT500c or the VT700c?


It is a 750, I think I will check out the kill switch first. It will likely take some time to solve unless I can find something obvious. It has only happened twice. But they occurrences were relatively close in time. It makes her a bit nervous to go very far from home.
alex
Perhaps I should have mentioned that this bike was originally a 700 the engine was exchanged for a 750 by the previous owner.
 

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Have had momentary cutouts which I attribute (right or wrong) to a water droplet in the fuel but usually it keeps going but it has not happened at idle. Agree that this sounds more like an electrical issue.

Suggest you analyse it to help locate; when does it happen (left, right, stop, bump, etc), when does it not happen, what is the difference between the two? Run/Stop is a good place to start, then check your battery posts, etc.
 

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Discussion Starter · #8 ·
Have had momentary cutouts which I attribute (right or wrong) to a water droplet in the fuel but usually it keeps going but it has not happened at idle. Agree that this sounds more like an electrical issue.

Suggest you analyse it to help locate; when does it happen (left, right, stop, bump, etc), when does it not happen, what is the difference between the two? Run/Stop is a good place to start, then check your battery posts, etc.
It shuts right down suddenly with no warning. She says there was a "click" just before it stopped. I have no idea what the click may have been. When it stops sher pulls over and It starts right up again. since From the info I get from her it happens while she is just cruising at highway speed on normal paved roads. She thought that the first time it happened it was because she was gong down a fairly steep hill and was low on fuel causing a momentary loss of fuel. This doesn't seem likely. It has only happened twice so it is hard to detect a pattern. I thought that may be some one had had a similar experience with this model and that it may have some quirk but that doesn't seem likely.
alex
 

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I've been having the same problem with my 85 VT1100C. Usually somewhere between 5-10 miles motor just stops. No indication that it is going to happen. Just cruising along and suddenly no more motor sound.

Sometimes it will restart after sitting a bit (I always open the gas cap to rule out a vent thing) with a few cranks and continue running the rest of the ride, sometimes it will happen a couple more times fairly soon after the first occourance, then keep running.

Doesn't happen everytime I ride, but often enough to be annoying.

I've used contact cleaner on my kill and ignition switches and it seemed to help, but it has done it again since the cleaning. I've also checked all the connections I can see and get to without disassembling.

There have been several threads addressing this issue, but the original poster's solution (if they found one) hasn't ever been posted in them. :-?
 

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Not familiar with this generation of Shadow so here is a question for other owners:
  • DOES THE RUN SWITCH GO TO A RELAY WHICH CONTROLS BOTH POWER TO THE STARTER AND MOTOR ENERGY (COILS, ETC)?
  • IF YES, IT POINTS TO YOUR SWITCH OR WIRING TO/FROM BOTH THE SWITCH AND RELAY.

If no, the 'click' she heard might be an arc when the pathway opened.

PS afterthought: you could use a jumper to bypass the run/kill and see if it does it again.
 

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Not familiar with this generation of Shadow so here is a question for other owners:
  • DOES THE RUN SWITCH GO TO A RELAY WHICH CONTROLS BOTH POWER TO THE STARTER AND MOTOR ENERGY (COILS, ETC)?
  • IF YES, IT POINTS TO YOUR SWITCH OR WIRING TO/FROM BOTH THE SWITCH AND RELAY.
If no, the 'click' she heard might be an arc when the pathway opened.

PS afterthought: you could use a jumper to bypass the run/kill and see if it does it again.
I'll have to check mine. When I have the ignition key on and then switch the kill switch to run, I do hear a click sound.
 

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Discussion Starter · #12 ·
Not familiar with this generation of Shadow so here is a question for other owners:
  • DOES THE RUN SWITCH GO TO A RELAY WHICH CONTROLS BOTH POWER TO THE STARTER AND MOTOR ENERGY (COILS, ETC)?
  • IF YES, IT POINTS TO YOUR SWITCH OR WIRING TO/FROM BOTH THE SWITCH AND RELAY.

If no, the 'click' she heard might be an arc when the pathway opened.

PS afterthought: you could use a jumper to bypass the run/kill and see if it does it again.
No click other than the sound of the switch. A jumper is in the plan.
alex
 

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Discussion Starter · #13 ·
I've been having the same problem with my 85 VT1100C. Usually somewhere between 5-10 miles motor just stops. No indication that it is going to happen. Just cruising along and suddenly no more motor sound.

Sometimes it will restart after sitting a bit (I always open the gas cap to rule out a vent thing) with a few cranks and continue running the rest of the ride, sometimes it will happen a couple more times fairly soon after the first occourance, then keep running.

Doesn't happen everytime I ride, but often enough to be annoying.

I've used contact cleaner on my kill and ignition switches and it seemed to help, but it has done it again since the cleaning. I've also checked all the connections I can see and get to without disassembling.

There have been several threads addressing this issue, but the original poster's solution (if they found one) hasn't ever been posted in them. :-?
Interesting.. Her's starts right up, or at least it has up to now. The 5 to 10 miles sounds familiar, I think that is about when she had the stoppage also. I went riding with her tonight and she stalled at a light at least that is what she thought but who knows the distance about matches your findings. She is a good rider so I was a bit surprised that she would stall so I am suspicious that it was the stopping problem.
If I find a solution I will post it but it may be awhile because it will be difficult to say that it is fixed unless something very positive is found so we can say "eureka".
alex
 

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To answer an earlier question: "DOES THE RUN SWITCH GO TO A RELAY WHICH CONTROLS BOTH POWER TO THE STARTER AND MOTOR ENERGY (COILS, ETC)?"

On the 83 - 85 VT700c/VT750c no it does not, the RUN/KILL switch gets its power directly from the ignition switch and then from the RUN/KILL switch the power goes directly to the ignition coils and ignition modules without going through anything else or to anything else, Honda put as few points of failure on this motorcycle as possible.
 
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