85 limited tachometer seems to be reading low


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airbats801
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85 limited tachometer seems to be reading low

Post by airbats801 » Mon Dec 03, 2018 3:40 am



I recently got my limited dash working with an 86 sei. I noticed the tach seems to be reading a bit low going by sound compared to my 84 aspencade. Seems like it';s idling around 900 and reading 450. Any ideas?



jwebfournow
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Re: 85 limited tachometer seems to be reading low

Post by jwebfournow » Sat Dec 29, 2018 3:06 pm

I have an 86 SEI and mine does the same, haven't been able to figure it yet.

airbats801
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Re: 85 limited tachometer seems to be reading low

Post by airbats801 » Sun Dec 30, 2018 2:48 am

seems like one of my coils was plugged in backwards. This fixed it

jwebfournow
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Re: 85 limited tachometer seems to be reading low

Post by jwebfournow » Sun Dec 30, 2018 11:39 am

You know I had thought of that it could be related to the coils also, but dreading unburying everything to get down in there to check. especially with the SEI's I did a coil pack on a regular Aspy and that was bad enough. Now you just gave me more incentive to get in there and root around!

airbats801
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Re: 85 limited tachometer seems to be reading low

Post by airbats801 » Sun Dec 30, 2018 6:16 pm

It's actually not too horribly bad. If you unbolt the coil bracket, which someone had left mine unbolted. You can slide it over enough to get your hands down in there, it's not fun, buy getting to it doesnt take too much time.

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Rednaxs60
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Re: 85 limited tachometer seems to be reading low

Post by Rednaxs60 » Sun Dec 30, 2018 7:22 pm

You should be able to get at the coil connections without removing the coils - takes patience but is quite doable. Have done this on my '85 LTD many times. In the supplement for my '85, page 7-6, indicates the coil polarity has no effect on performance. This to me is that these coils are not polarity sensitive. Have had mine out and there are no markings on these coils to indicate polarity.
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airbats801
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Re: 85 limited tachometer seems to be reading low

Post by airbats801 » Sun Dec 30, 2018 9:33 pm

interesting One of my coils wasnt even firing, maybe it wasnt connected very well to begin with? I really dont know. I did notice the wires on one coil were swapped opposite of the other, so I assumed that was the issue. It did work afterwards.

From some reading, the coil polarity shouldnt matter, and in more likely hood maybe the wire wasnt connected very good. I had been riding around on 2 cylindersd for a short trip. Dang, that bike came alive when all 4 were firing.

I think the low reading has to do with one coil not firing.

One thing though, I believe reversing polarity of the coil will affect the sparkplug performance. something like 15% less voltage when properly wired to form an arc? I'm not sure how relevant that is to anything, but this is a interesting read
http://www.mossmotoring.com/coil-polarity/

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Re: 85 limited tachometer seems to be reading low

Post by WingAdmin » Mon Dec 31, 2018 12:33 pm

airbats801 wrote:
Sun Dec 30, 2018 9:33 pm
interesting One of my coils wasnt even firing, maybe it wasnt connected very well to begin with? I really dont know. I did notice the wires on one coil were swapped opposite of the other, so I assumed that was the issue. It did work afterwards.

From some reading, the coil polarity shouldnt matter, and in more likely hood maybe the wire wasnt connected very good. I had been riding around on 2 cylindersd for a short trip. Dang, that bike came alive when all 4 were firing.

I think the low reading has to do with one coil not firing.

One thing though, I believe reversing polarity of the coil will affect the sparkplug performance. something like 15% less voltage when properly wired to form an arc? I'm not sure how relevant that is to anything, but this is a interesting read
http://www.mossmotoring.com/coil-polarity/
That may be so, but it will have zero effect on your Goldwing. The Goldwings use wasted spark, where one coil is used to spark two plugs. One plug is connected to one side of the coil, the other plug is connected to the other side of the coil. So one plug is arcing from ground to electrode, the other is arcing from electrode to ground. Reversing the polarity of the coil will make no difference.

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airbats801
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Re: 85 limited tachometer seems to be reading low

Post by airbats801 » Mon Dec 31, 2018 9:21 pm

You can debate it all day long, I just answered the thread to let people know what fixed it.



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