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1Back to top Go down   Testing coils or HT leads hot Empty Testing coils or HT leads hot Mon Apr 02, 2012 3:35 pm

Moto Smith

Moto Smith
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I have a problem with the engine falling away from idle when it is hot - hotter than average.

Under 80F, I don't have a problem at all. Above 80F, especially if I have been involved in a series of traffic lights or stop and go traffic, the engine want to die. I have to keep blipping the throttle to keep it alive.

I have replaced the fuel pump and filters as part of an ongoing maintenance program. Ditto the spark plugs. I have the fuel pressure regulator and vacuum hose on-hand ready to replace also.

I'm wondering if the coils, when hot, have a break that opens up. The bike runs fine past idle.

Any thoughts??


Cheers, M


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

2Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Mon Apr 02, 2012 6:47 pm

charlie99

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hmm interesting issue moto ....

i wonder if your plugs are the right heat range .

quite a few of us use ngk d7ea ....unfortunatly i dont have a cross reference to other brands

as to the coils having a crack ,,,,,maybe this could be tested in a darkened garage or similar ...undo the coil covers and you should be able to see any high voltage spike arcing over along the high tension path

i recall that there has been made note that the hall effect sensors could become unstable with temperature

there is a testing tecnique in the "efi trouble shooting" thread-weblinks by bert ....found on the "portal page "

i guess a hair dryer could localize heat affects for this testing

i would also check the fuel cap seals and breather tubes for being "open" could heat be affecting the fuel supply by vapour lock issues in or around the tank ?


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OTesting coils or HT leads hot Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

3Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Mon Apr 02, 2012 8:30 pm

Inge K.

Inge K.
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Usually when it`s heat related problems with hall sensors, the engine cuts completly the affected cylinders.

Vapour lock? Could be a idea to try to wrap the fuel lines with some heat isolating stuff?


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

4Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Tue Apr 03, 2012 5:02 am

komandoalicante

komandoalicante
Silver member
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@Inge K. wrote:Usually when it`s heat related problems with hall sensors, the engine cuts completly the affected cylinders.

Vapour lock? Could be a idea to try to wrap the fuel lines with some heat isolating stuff?


+1 (I think the same)


__________________________________________________
SAK3 and komandoalicante is the same person

In March we made a International meeting of BMW motorcycle K in  Spain.

The last meeeting 6ª Editions March 2015

6ª international meeting BMW K
Testing coils or HT leads hot 7cnp
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5Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Tue Apr 03, 2012 12:43 pm

Moto Smith

Moto Smith
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Silver member
[quote="charlie99"]hmm interesting issue moto ....



there is a testing tecnique in the "efi trouble shooting" thread-weblinks by bert ....found on the "portal page "

I looked at Bert's EFI sheet - that was definitely a labor of love. Thank you!

I think that I need to test fuel pressure when the vehicle is hot as my next move.

Cheers, M


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

6Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Tue Apr 03, 2012 5:45 pm

Moto Smith

Moto Smith
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[quote="charlie99"]hmm interesting issue moto ....

i wonder if your plugs are the right heat range .

quite a few of us use ngk d7ea ....unfortunatly i dont have a cross reference to other brands

I removed some Autolite plugs 4153 from the bike last Saturday - not because of heat range, but because I was replacing old with new.
I put in Bosch plugs.

The autolite plugs convert to boschXR4CS

Now I'm going to have to wait for a 80 degree day to see if that solved the problem.

Cheers, Mark


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

7Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Tue Apr 03, 2012 6:14 pm

Inge K.

Inge K.
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@Moto Smith wrote:The autolite plugs convert to boschXR4CS
If you got the genuine HT leads and caps, you should use Bosch X5DC.
If you got non genuine caps w/o resistors, the XR type is correct.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

8Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Tue Apr 03, 2012 6:47 pm

charlie99

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[quote="Moto Smith

I removed some Autolite plugs 4153 from the bike last Saturday - not because of heat range, but because I was replacing old with new.
Cheers, Mark[/quote]

what did the electrodes look like mark ? black white or golden ?

old school mechanics always looked there first ...


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OTesting coils or HT leads hot Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

9Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 12:52 am

Moto Smith

Moto Smith
Silver member
Silver member
@charlie99 wrote:[quote="Moto Smith

I removed some Autolite plugs 4153 from the bike last Saturday - not because of heat range, but because I was replacing old with new.
Cheers, Mark

what did the electrodes look like mark ? black white or golden ?

old school mechanics always looked there first ...[/quote]

The plugs looked great - a nice tan color.

OK, so today I ride 150 miles in 88F with an hour thru a city and not a problem.
The only thing that I've changed in recent history is the spark plugs...

Cheers, M


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

10Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 5:17 am

charlie99

charlie99
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well thats a start ....what about the fuel load whilst doing this ?

did i see in here some one got 3/4 full tank and the issues started .....from memory he solved it with replacing the fuel tank lid seals

just a thought


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OTesting coils or HT leads hot Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

11Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 11:32 am

Moto Smith

Moto Smith
Silver member
Silver member
@charlie99 wrote:well thats a start ....what about the fuel load whilst doing this ?

did i see in here some one got 3/4 full tank and the issues started .....from memory he solved it with replacing the fuel tank lid seals

just a thought

Yes, that was me. I had a perimeter crack around the valve of the cap and replaced the whole cap.

I have the fuel pressure reg that I will change out in the near future - that will make pump, filters and reg all replaced as part of preventative maintenance.

Also, my MPG just increased with the new spark plugs - I don't know what happened there, but I'm getting about 4-5 more MPG.

Cheers, M


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

12Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 2:05 pm

charlie99

charlie99
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hey.... thats a great result ...


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OTesting coils or HT leads hot Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

13Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 4:02 pm

sidecar paul

sidecar paul
Life time member
Life time member
Moto,
Quote:- "Also, my MPG just increased with the new spark plugs - I don't know what happened there, but I'm getting about 4-5 more MPG."

If you change your plugs ten times, will your tank overflow? Testing coils or HT leads hot 652573

Paul.


__________________________________________________
'84 K100RS (0014643) (owned since '85), 86 K100RS (0018891) with Martello sidecar (built as an outfit in '88),
'51 Vincent (since '67),'72 Montesa Cota (from new), '87 Honda RS125R NF4 (bought 2015) 
....No CARS never ever!
    

14Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 4:06 pm

Moto Smith

Moto Smith
Silver member
Silver member
@sidecar paul wrote:Moto,
Quote:- "Also, my MPG just increased with the new spark plugs - I don't know what happened there, but I'm getting about 4-5 more MPG."

If you change your plugs ten times, will your tank overflow? Testing coils or HT leads hot 652573

Paul.

I don't know about the tank overflowing, but I should be near to 70 MPG following that logic.

I wonder what will happen if I change the oil filter again?

Cheers, M


__________________________________________________
87 K100RS - Pichler fairing (PK2)
http://www.markaspery.com
    

15Back to top Go down   Testing coils or HT leads hot Empty Re: Testing coils or HT leads hot Wed Apr 04, 2012 7:00 pm

charlie99

charlie99
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Testing coils or HT leads hot 44271


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OTesting coils or HT leads hot Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

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