Wouldn't the bike's performance (running on 3 cylinders) be pretty obvious if the spark plug wire were so loose as to allow that cylinder to get no spark?
Loose spark plug leads
- Thread starter DavidR8
- Start date
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
It was definitely not seated correctly but it was making contact with the plug.
The performance was a bit off as there was a fair degree of vibration above 4000 rpm and starting from a standstill took some throttle to get into the 2000-2200 rpm range. Even then it sounded distinctly ‘rattlely'.
Sent from my iPhone using Tapatalk
Andrew Shadow
Site Supporter
I saw it in Walmart here in Canada.
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
- Joined
- Mar 18, 2006
- Messages
- 2,824
- Age
- 70
- Location
- Ilkley, W Yorkshire, UK
- Bike
- 2013 ST1300 A9
- 2024 Miles
- 000679
- STOC #
- 2570
That plug lead should screw into the plug cap quite a long way. It is difficult to tell how far inside it is seated, but I marked one of mine with felt pen before I took it off a few years ago - it was about an inch. A felt pen mark an inch from the end of the HT lead before you start to screw it in will help to inform you of how far to screw it in. A little silicon lubricant on the end also helps. The HT lead shouldn't normally just come loose - unless the PO tried to just push it on (like you have to at the coil end - but that has a gland to keep it secured), OR the copper core of the wire is corroded. If it is - it is very obvious - there will be visible signs of light green copper oxide - Verdigris - in the core.
Pictures show (1) the marked HT lead and the depth to which it was screwed into the plug cap; (2) the coil end of the HT lead with the glued on grommit, the tiny washer and the gland nut. Again, it goes into the coil a long way - but this end is a push fit.
it is possible to use bog standard copper cored HT lead, but the OEM part comes with an additional outer sheath, and that all important glued-on grommet. An alternative to the grommet needs to be found for a replacement lead which can be secured to the HT lead - as it is only this that keeps the HT lead firmly located in the coil. That tiny washer allows the gland nut to be tightened without twisting the grommet.
Last edited:
STumped
Because I usually am . . . .
I wonder what impact fixing this will have on your (poor) gas mileage. Let us know on your next tank how things (hopefully) improved.
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
Well already today I could tell a difference.I wonder what impact fixing this will have on your (poor) gas mileage. Let us know on your next tank how things (hopefully) improved.
I know the readouts are not considered accurate however we started our ride today with the tank average at 8.8 km/l. We rode around for maybe 60 mins at low speed, two up and by the time we got back home the tank average was at 10.2 km/l.
Previously I could not reach a tank average of more than 9.3 km/l.
So that's going in the right direction
Sent from my iPhone using Tapatalk
Last edited:
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
Thanks, the problem I found was even more simple than this.That plug lead should screw into the plug cap quite a long way. It is difficult to tell how far inside it is seated, but I marked one of mine with felt pen before I took it off a few years ago - it was about an inch. A felt pen mark an inch from the end of the HT lead before you start to screw it in will help to inform you of how far to screw it in. A little silicon lubricant on the end also helps. The HT lead shouldn't normally just come loose - unless the PO tried to just push it on (like you have to at the coil end - but that has a gland to keep it secured), OR the copper core of the wire is corroded. If it is - it is very obvious - there will be visible signs of light green copper oxide - Verdigris - in the core.
Pictures show (1) the marked HT lead and the depth to which it was screwed into the plug cap; (2) the coil end of the HT lead with the glued on grommit, the tiny washer and the gland nut. Again, it goes into the coil a long way - but this end is a push fit.
it is possible to use bog standard copper cored HT lead, but the OEM part comes with an additional outer sheath, and that all important glued-on grommet. An alternative to the grommet needs to be found for a replacement lead which can be secured to the HT lead - as it is only this that keeps the HT lead firmly located in the coil. That tiny washer allows the gland nut to be tightened without twisting the grommet.
The boot part of the assembly was not firmly connected to the spark plug. It was simply resting on it. It took some effort to remove the other three boots but the #3 was just loose.
As an aside, if anyone has a good method of pulling the sparkplug boots off I'm all ears as it was very difficult for me to do with the limited space and cable slack.
- Joined
- Nov 20, 2005
- Messages
- 9,514
- Location
- Cedar City, Utah
- Bike
- 12/04 ST 1300s
- 2024 Miles
- 000148
- STOC #
- 5901
They call those two strokes!
- Joined
- Mar 18, 2006
- Messages
- 2,824
- Age
- 70
- Location
- Ilkley, W Yorkshire, UK
- Bike
- 2013 ST1300 A9
- 2024 Miles
- 000679
- STOC #
- 2570
Ah - me overthinking a problem again. So further down the road when you have a problem that matches my solution, you'll know where to look !
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
Not at all. I wasn't particularly clear on what part of the circuit was loose
Sent from my iPhone using Tapatalk
MajorTom
QuickBlue
So nothing related to fuel additives at all, except maybe a bit mixed with the unburned fuel.
Glad to hear you're making progress on your fuel consumption woes. Did you install that expensive new thermostat yet? Curious if that makes a difference to your fuel economy. I know it did on my '04.
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
New thermostat is in. It did make a difference to warm up time and I was beginning to see the temp waver on cool mornings.So nothing related to fuel additives at all, except maybe a bit mixed with the unburned fuel.
Most importantly was discovering that the bike was intermittently running on three cylinders. On my commute home which is entirely under 60 kmh the average kms/l never dropped below 10 whereas last week it was down in the mid to high 8's. And that was with me being very conservative.
I'll likely fill up tomorrow, reset everything and start calculating again.
Sent from my iPhone using Tapatalk
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
Update: filled up after work today and managed to sneak over the 23 mpg mark!
This is very positive because I was well into this tank when I discovered the loose spark plug lead.
I put two ounces of Marvel Mystery Oil in with the fill tonight.
Feeling hopeful!
Sent from my iPhone using Tapatalk
This is very positive because I was well into this tank when I discovered the loose spark plug lead.
I put two ounces of Marvel Mystery Oil in with the fill tonight.
Feeling hopeful!
Sent from my iPhone using Tapatalk
Last edited:
STumped
Because I usually am . . . .
Looks like you found the cause of your poor mileage. Next tank should confirm.....keep us posted!
OP
OP
DavidR8
Site Supporter
- Joined
- May 31, 2017
- Messages
- 1,221
- Location
- Vancouver Island, British Columbia
- Bike
- 2013 BMW R1200RT
- STOC #
- 8968
Too bad the weather is turning a bit off here today. Though looks to be clearing up through the week.Looks like you found the cause of your poor mileage. Next tank should confirm.....keep us posted!
My desire to ride is huge! Only 1700 kms since we bought her at the beginning of September.
Sent from my iPhone using Tapatalk