Author Topic: Misfires above 4,500  (Read 6713 times)

Offline jon stead

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Re: Misfires above 4,500
« Reply #45 on: September 29, 2017, 04:50:30 PM »
i would also remove valves on the affected cylinder in case one is bent or not seated properly

The head was fully rebuilt, new valves, guides, recut seats, skimmed and all checked before reassembly. The fault was there before the head rebuild and still there afterwards.

Worth saying here, although I'm trying to forget about it, the head was only rebuilt because my fist made out of hams bent all eight valves and cracked the guides putting the cylinder cover on wrongly after checking the valve timing.
2015 Triumph Bonneville T100 Newchurch

Offline kevski

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Re: Misfires above 4,500
« Reply #46 on: September 29, 2017, 05:24:51 PM »
Are you getting a constant 12v at the coils, Boyer say 9v, if no the ignition will play up, frankly you need to start at the beginning when put back together, a few years ago i had Z thou that would do this, everything was as it should have been apart from exhaust, i put an original system on, problem solved, still puzzled as to why it happened like that.

Offline jon stead

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Re: Misfires above 4,500
« Reply #47 on: September 29, 2017, 05:35:32 PM »
Are you getting a constant 12v at the coils, Boyer say 9v, if no the ignition will play up, frankly you need to start at the beginning when put back together, a few years ago i had Z thou that would do this, everything was as it should have been apart from exhaust, i put an original system on, problem solved, still puzzled as to why it happened like that.

I haven't measured the voltage at the coils but I will, good idea.
2015 Triumph Bonneville T100 Newchurch

Offline Rob62

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Re: Misfires above 4,500
« Reply #48 on: September 29, 2017, 10:15:42 PM »
Just a simple thought but have you checked the fuel tank vent.... does the problem occurr immediately or after a few mins of running? Blocked or partially blocked vent wouldn't slow the fuel flow down immediately so a flow test might show up ok... but the flow would reduce after a while..

Offline jon stead

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Re: Misfires above 4,500
« Reply #49 on: September 30, 2017, 07:59:44 AM »
Just a simple thought but have you checked the fuel tank vent.... does the problem occurr immediately or after a few mins of running? Blocked or partially blocked vent wouldn't slow the fuel flow down immediately so a flow test might show up ok... but the flow would reduce after a while..

Yes I did that. I took the cap apart and proved all clear, spring free etc. I even drove the bike with the filler cap open,  no difference.
2015 Triumph Bonneville T100 Newchurch

Offline Johnwebley

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Re: Misfires above 4,500
« Reply #50 on: September 30, 2017, 10:58:41 AM »
just a thought,

  I once had a faulty coil,worked ok on start up,but after a mile or so it stopped ,when it warmed up,

 that took ages to sort out
lifelong motorcycle rider,and fan

Offline jon stead

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Re: Misfires above 4,500
« Reply #51 on: September 30, 2017, 01:47:02 PM »
just a thought,

  I once had a faulty coil,worked ok on start up,but after a mile or so it stopped ,when it warmed up,

 that took ages to sort out

Yes, I'm hoping it's a coil thing. I've swapped the coils but waiting now on the head coming back. If the sooty plug problem moves to 1 or 4 then it's the coil.
2015 Triumph Bonneville T100 Newchurch

Offline jon stead

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Re: Misfires above 4,500
« Reply #52 on: October 04, 2017, 06:44:16 PM »
Got my cylinder head back with four steel plug inserts now installed. Hopefully get it back on and running tomorrow before I go away again.

Watch this space!
2015 Triumph Bonneville T100 Newchurch

Offline Johnwebley

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Re: Misfires above 4,500
« Reply #53 on: October 04, 2017, 08:17:10 PM »
Got my cylinder head back with four steel plug inserts now installed. Hopefully get it back on and running tomorrow before I go away again.

Watch this space!


  fingers crossed !!
lifelong motorcycle rider,and fan

Offline jon stead

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Re: Misfires above 4,500
« Reply #54 on: October 06, 2017, 10:31:38 AM »
Got it all back together, again, fired up no problem. Misfire still there but didn’t have time to ride it long enough to see if sooty plug has moved since coil swap. I’m away again so fault finding will continue upon my return.
2015 Triumph Bonneville T100 Newchurch

Offline jon stead

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Re: Misfires above 4,500
« Reply #55 on: October 11, 2017, 02:32:53 PM »
Removed Boyer ignition and coils. Fitted Dyna S back plate and the coils that came with the bike when I first bought it.
Fired up first time, dynamically set timing and away we went. Seemed better but still not right. Removed plugs, #3 sooty, but this could’ve been from before ignition swap. Cleaned plugs and regapped to 35 thou from 25 thou.
I also swapped my live and ground wires on the coils as I don’t know which terminal is positive or negative and even if it really matters?
Went out on it again and pulls much better. Going to keep using it and see how it goes. Rained off at present.
2015 Triumph Bonneville T100 Newchurch

Offline jon stead

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Re: Misfires above 4,500
« Reply #56 on: October 11, 2017, 03:08:59 PM »
2015 Triumph Bonneville T100 Newchurch

Offline Rob62

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Re: Misfires above 4,500
« Reply #57 on: October 11, 2017, 07:09:44 PM »
Wow!! Very nice  8) 8)

Offline Johnwebley

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Re: Misfires above 4,500
« Reply #58 on: October 11, 2017, 08:02:11 PM »


   the plug gap should be 27 thou,

  non resistor plugs, and resistor plug caps ,

   

 
lifelong motorcycle rider,and fan

Offline jon stead

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Re: Misfires above 4,500
« Reply #59 on: October 11, 2017, 11:01:27 PM »


   the plug gap should be 27 thou,

  non resistor plugs, and resistor plug caps ,

   

 

I’m using non resistor plugs and 5kohm resistor plug caps. I’m sure I read somewhere on Dynatek site, to set plug gaps between 0.035 and 0.040”
2015 Triumph Bonneville T100 Newchurch

 

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