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Misfire under load? Thoughts?

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  #11  
Old 09-26-2016 | 09:06 AM
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Originally Posted by Mr_Taipan
True but then a dyno tune is static to the bikes set up, which is something I like to keep changing. So the PV is the best option for me.
In which case you could find yourself chasing your tail every time you change something!
 
  #12  
Old 09-27-2016 | 04:26 AM
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I checked the battery terminals were tight and they were although if I pushed hard enough the earth could be moved. I'll put one of those grip or spring washers on there later.

Had a good look round at the various wiring connectors but couldn't see anything amiss. So I decided to check the plugs. They looked okay to me but the gap was too small, so I regapped them.

As I had made soem changes I thought I wont change the ECU map until i've tested it. Rode up the road and it stumbled a bit as I accelerated, so i figured I'd get some fuel and then load up the original map.

By the time I got to the petrol station it seemed to have cleared itself? So I thought i'll leave the map for now and just ride it into work and see how it goes. My commute is about 30 miles door to door and about half of that is highway, so I sat at a near constant 80mph. Once in town I gave it a good full throttle blasts but no misfire at all?

Whilst I'm pleased its fixed I wished I knew exactly what it was? Cant see it being the battery terminal as that was tight really. So maybe the plug gap being slightly too small caused it? I'll use the bike for the rest of the week and just hope that's an end to it?



 
  #13  
Old 09-27-2016 | 06:08 AM
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You mave have shaken a little corrosion from the battery terminal when you repositioned the terminal end.
You don't need a big build up for a bad connection.
 
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  #14  
Old 09-27-2016 | 06:47 AM
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Originally Posted by Guzzi
You mave have shaken a little corrosion from the battery terminal when you repositioned the terminal end.
You don't need a big build up for a bad connection.
Yup. I'm definitely going to have at the battery terminals and lead ends with wire wool and put petroleum jelly on them when they are tightened up again. Just can't work out why it still stumbled/misfired at first but then cleared? As much as I'm pleased its working again, I kinda hate things fixing themselves without me knowing the actual cause. Makes me think it can do it again. Still, its nice to have the old girl running at full steam again!
 
  #15  
Old 09-27-2016 | 07:31 AM
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Is it possible you had a bad batch of gas?
 
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  #16  
Old 09-27-2016 | 09:34 AM
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Originally Posted by Ratwerke
Is it possible you had a bad batch of gas?
Doubtful. Its pretty much unheard of here...
 
  #17  
Old 09-27-2016 | 03:32 PM
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I know on my bikes I often have to tighten the battery terminals. In about 1.5 months of riding they get lose. On my sportie that’s about 1200 miles or so. Less miles on the bagger but they still get lose. Even my INDY told me - hey keep up on your terminals, they get lose. He's been a wrench for over 30+ years...

Batteries are funny sometimes. A lose terminal can put excessive load on things. Terminals are never a tighten and forget thing. Just the nature of HD beast shaking the crap outta everything...less the new M8.

I can usually get about 1/2 turn or more on the terminals if not a bit more when they are lose. Yea that’s with star washers in place under the lugs too. On my bagger I've LEDs installed so I've more things under the battery lug screws. BUT even on my sportie where the lugs are just what the bike called for from the factory - they get lose too.

Hopefully you cured it. However as you say since you like to tinker and change often...you sort of ask for inconsistency a bit IMO. NO problem with that it’s all about fun.

Ride safe!
 
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  #18  
Old 09-28-2016 | 03:52 AM
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Originally Posted by GMRO
I know on my bikes I often have to tighten the battery terminals. In about 1.5 months of riding they get lose. On my sportie that’s about 1200 miles or so. Less miles on the bagger but they still get lose. Even my INDY told me - hey keep up on your terminals, they get lose. He's been a wrench for over 30+ years...

Batteries are funny sometimes. A lose terminal can put excessive load on things. Terminals are never a tighten and forget thing. Just the nature of HD beast shaking the crap outta everything...less the new M8.

I can usually get about 1/2 turn or more on the terminals if not a bit more when they are lose. Yea that’s with star washers in place under the lugs too. On my bagger I've LEDs installed so I've more things under the battery lug screws. BUT even on my sportie where the lugs are just what the bike called for from the factory - they get lose too.

Hopefully you cured it. However as you say since you like to tinker and change often...you sort of ask for inconsistency a bit IMO. NO problem with that it’s all about fun.

Ride safe!

You know I think you're right. The only other time it played up was down to teh earth terminal being, well not loose, but not fully tight. Although this time I didn't get the speedo drop thing, but similar stumble in power delivery. Apart from the plugs being a fraction out, it was the only other change I made and i just cant see it being the plug gap.

I'll do a regular check on the terminals from now as that's is good advice.

Many thanks
 
  #19  
Old 09-28-2016 | 01:16 PM
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With the very reliable Kawasaki Vulcan 1500/1600 series a miss or sputter is normally a sure sign of a bad battery or connection. My Vulcan 1600 started missing at highway speeds, and sure enough it was a bad battery terminal.
 
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  #20  
Old 09-28-2016 | 02:10 PM
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Originally Posted by Mr_Taipan
You know I think you're right. The only other time it played up was down to teh earth terminal being, well not loose, but not fully tight. Although this time I didn't get the speedo drop thing, but similar stumble in power delivery. Apart from the plugs being a fraction out, it was the only other change I made and i just cant see it being the plug gap.

I'll do a regular check on the terminals from now as that's is good advice.

Many thanks
Only once or twice have I had to mess/tighten the red/hot wire going to the starter and the main ground frame negative wire. I've checked them with a wrench...of course HOT...so be careful to not touch red to frame and weld! Mostly it's the 2 lugs at the battery.
 
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