[Roeland]

About 500 km ago I changed the standard main Bosch spark plug on my twin spark with the NGK BPR6EIX6637. Initially I felt quite a boost in performance but the map on my PC5 is way to rich for the NGK spark plug to handle. The plug fouls with oil to the stage the bike stops idling. Should I look at a hotter NGK plug or stick with the Bosch plug?

[ace.cafe]

I don't understand why it fouls with oil. Are the valve stem seals compromised or something?

[High On Octane]

Maybe you should attach a pic of the spark plug.  A rich tune can cause a plug to foul but it will be a dry black and sooty.  If the plug is oil fouled, you either have a valve seat problem or bad piston rings.  You A/F ratio has absolutely nothing to do with oil getting on the plug.

Scottie J

[Roeland]

Maybe you should attach a pic of the spark plug.  A rich tune can cause a plug to foul but it will be a dry black and sooty.  If the plug is oil fouled, you either have a valve seat problem or bad piston rings.  You A/F ratio has absolutely nothing to do with oil getting on the plug.

Scottie It's not oil - just rich on petrol. I changed back to the Bosch plug and it is all perfect?

[Roeland]

I don't understand why it fouls with oil. Are the valve stem seals compromised or something?

Ace - it's not oil but petrol - just too much for the NGK? Aboslutly no oil consumption? But the plug is black as go can get black and the power commander Autotune commands less petrol at -5 at most levels (the maximum I allowed it)

[gashousegorilla]

  Roland, What Bosch plug did you pull out vs the NGK plug ?...  Heat range wise ? Is the plug fouling at idle or around town slow speed stuff ?  Or you take it out for a good run and it's fouled ? How is the motor currently modified ?   I don't know amount the twin spark IDM bike's MAP,  But the ones here dump a lot of fuel in at start up and idle... so depending on how your motor has been modified, -5 MAY still be too rich at zero throttle position and say... 500-1250 rpm's. You shooting for a richer start and idle,  but not too rich.  Shoot for a target afr of around 12 to 1 at cold idle and tweak it from there.  You may have to go a little richer or leaner from there. and don't forget... your idle air screw is going to play a roll.  Your looking for the best combination, for the way your bike has been modified, for the plugs heat range, AFR's, idle  across the range from start up to WOT rippin' down the highway. 

[High On Octane]

Roeland - If you're rocking a Power Commander you HAVE to get your bike on a dyno with a sniffer and get your fuel map tuned.  That's the downfall to programmers, auto tune features are only for getting the motor running, it is required to take the info from the auto tune and then tune the motor accordingly.  This usually requires 2-5 different maps before you get it perfect.  At least your extremely rich and not extremely lean.

Scottie J

[gashousegorilla]

Roeland - If you're rocking a Power Commander you HAVE to get your bike on a dyno with a sniffer and get your fuel map tuned.  That's the downfall to programmers, auto tune features are only for getting the motor running, it is required to take the info from the auto tune and then tune the motor accordingly.  This usually requires 2-5 different maps before you get it perfect.  At least your extremely rich and not extremely lean.

Scottie J

  Naaaa.... Not really Scott. You can nail it down in one shot on the Dyno... unless you keep modifying the bike. At idle, you really don't need the Dyno as much as a sniffer. If you know what you afr's are at idle from when you were on the Dyno with the sniffer, you can tweak the numbers from there fatter or leaner. And I believe Rolands auto tune with the wide band 02 sensor is telling him what the afr's are... But if he limits the numbers to a + or -  5 percent fuel correction, he wont be able to hit his target afr numbers.  I believe Dynojet recommends no more then a + or - 5 percent at a time to be cautious, and not so you go crazy lean or rich when your tuning. 

[High On Octane]

Maybe that's just how the turbo boys tune then. 

[gashousegorilla]

Maybe that's just how the turbo boys tune then. 

 LOL !.... Yes , I imagine they would. One for the street and one for the track.  And come on man !  Turbo or supercharging is cheatin'  !       Real men go natural  .   And yes, it is good to have a map switch for the street as well. If you want to use a map for power, or one for economy.   But personally ?.... who cares about economy     

[Roeland]

  Roland, What Bosch plug did you pull out vs the NGK plug ?...  Heat range wise ? Is the plug fouling at idle or around town slow speed stuff ?  Or you take it out for a good run and it's fouled ? How is the motor currently modified ?   I don't know amount the twin spark IDM bike's MAP,  But the ones here dump a lot of fuel in at start up and idle... so depending on how your motor has been modified, -5 MAY still be too rich at zero throttle position and say... 500-1250 rpm's. You shooting for a richer start and idle,  but not too rich.  Shoot for a target afr of around 12 to 1 at cold idle and tweak it from there.  You may have to go a little richer or leaner from there. and don't forget... your idle air screw is going to play a roll.  Your looking for the best combination, for the way your bike has been modified, for the plugs heat range, AFR's, idle  across the range from start up to WOT rippin' down the highway.

I used a WR8DP plug in combination with a UR6DC.  I enriched the fuel in first gear 0 throttle position mapping by +2 at idle and this gives me a fuel ratio of 14 to 1 at idle only. From there I use a AFR ratio of 13.6:1 and richer. The PC5 map was about perfect and only small adjustments took place with the Autotune; usually only 1 and 2's up or down. Maximum fuel demand goes up to about +30 and down to about -30, depending on gear and revs. But after removing the "black" NGK especially 5th gear map was indicating a -5 all over. Perhaps the plug was faulty to start with and I was running on the secondary plug only? I will test the plug tonight.

[gashousegorilla]

 It sounds like you put in a colder NGK plug. The Bosch 8 plug crosses to an NGK 5 plug... not a 6.  And the PC-V  may have picked up a little fatter mix off the colder plug. Then when you changed it back, it started taking a little fuel out. 5 % percent either way is not much.   So you have a hotter primary plug and a little colder secondary plug it looks like. Whatever heat range plug you use , I would stick with it... Personally, I like to stay on the colder side for saftey at WOT. And I might go one heat range hotter in the cold months for easier starting.

 And Auto tune limits changes at minus or plus 30 % ?  Or is that just their recommendation not to exceed ?  I have fuels corrections above 50% in some area's off the Dyno... but my bike is a little different , and I'm a little richer on the mix.

 That 14 to 1 you get at idle, does it does it richen up as the bike warms, or is that your at full temp AFR ? 


 http://www.hotrodders.com/forum/attachment.php?attachmentid=93010&d=1382792281

[Roeland]

It sounds like you put in a colder NGK plug. The Bosch 8 plug crosses to an NGK 5 plug... not a 6.  And the PC-V  may have picked up a little fatter mix off the colder plug. Then when you changed it back, it started taking a little fuel out. 5 % percent either way is not much.   So you have a hotter primary plug and a little colder secondary plug it looks like. Whatever heat range plug you use , I would stick with it... Personally, I like to stay on the colder side for safety at WOT. And I might go one heat range hotter in the cold months for easier starting.

 And Auto tune limits changes at minus or plus 30 % ?  Or is that just their recommendation not to exceed ?  I have fuels corrections above 50% in some area's off the Dyno... but my bike is a little different , and I'm a little richer on the mix.

 That 14 to 1 you get at idle, does it does it richen up as the bike warms, or is that your at full temp AFR ? 


 http://www.hotrodders.com/forum/attachment.php?attachmentid=93010&d=1382792281

Very interesting - the NGK 6 range was recommended by NGK as a replacement for the Bosch plug. I still have this on email somewhere. Maybe I should try the NGK 5 range. Unfortunately it is rather difficult to get hold of these plugs over here. They are not readily available and usually need to be ordered. Yes 5% either way is not much but that's the maximum limit I set the PC5 to auto change the mixture between manually accepting and fine tuning the AFR values. If one does not do this you may get erratic AFR values, especially in the lower gears at low throttle. The +30% fuel correction is in 5th gear at the lower gears it adds more - in first I get instances of +56. Maybe I don't push it hard enough in 5th?
The 14:1 is with a mildly warmed engine +- 40 to 50 degree C. I cannot recall the value when fully warmed up at 80 degree C, but I will check on that next time.

[meph1st0]

The below link contains alternatives for WR8DP
http://www.sparkplug-crossreference.com/convert/BOSCH_PN/WR8DP

[gashousegorilla]

Very interesting - the NGK 6 range was recommended by NGK as a replacement for the Bosch plug. I still have this on email somewhere. Maybe I should try the NGK 5 range. Unfortunately it is rather difficult to get hold of these plugs over here. They are not readily available and usually need to be ordered. Yes 5% either way is not much but that's the maximum limit I set the PC5 to auto change the mixture between manually accepting and fine tuning the AFR values. If one does not do this you may get erratic AFR values, especially in the lower gears at low throttle. The +30% fuel correction is in 5th gear at the lower gears it adds more - in first I get instances of +56. Maybe I don't push it hard enough in 5th?
The 14:1 is with a mildly warmed engine +- 40 to 50 degree C. I cannot recall the value when fully warmed up at 80 degree C, but I will check on that next time.

 I'm thinking that maybe that recommendation was for the single plugged heads.   And no, I don't have any +50 numbers up high either.   A lot of negative numbers , a lot of positive numbers. But nothing as high as the 50's.  I think it might be a little harder to tune it in fifth on the road with the auto tune.... You would need a Looooong straightaway, and hold the throttle at the different positions and try to get it as close the redline as you could. And I guess with the auto tune you would have to tune per gear, or the motor would be lugging without a roller , like on a Dyno loading the bike.

  When I adjust fuel at idle, I have a Thermostat from my multi meter stuck into the slot in the fins on the head, near the plug, to monitor temp. And I put a fan on the motor for safety.  I get it to operating temp and adjust my idle with the screw and or adjusting the AFR's.  Then I let the bike cool down to ambient temperature with the fan. Then I check my cold starts and tweak the numbers up or down from 500-1250, zero throttle.  I might go back and forth a bit till I like it. It helps me to know what the AFR's are at full operating temp and simulating a hot motor sitting in traffic....  I don't want to be too lean in that condition, and it helps to know when I do tweak those numbers at zero throttle.