Ideal spark plugs for M10 with twin Webers?

[Mike Self]

2 hours ago, NickVyse said:

3 hours ago, KFunk said:

I’ve just been running good ole NGK BP6ES forever, I think. Around 11 years on DCOEs. The 5 is a little hotter and the 7 is a little colder if that’s what you want.  I’ve run the bp6es with stock cam and points, and now 292 with cranecam xr3000 with ps91 coil.  Can’t say if they’re perfect, but never given me any problems.

 

what he said

Me too--I switched to NGKs some years ago after I had a bad run of Bosch plugs, both in my BMWs and in my Nissan pickup truck.  

 

Conventional wisdom is not to use platinum plugs in an M10--and I suspect that's due to the conventional ignition system.  Platinum plug electrodes are tiny and will foul quickly unless you have a high voltage ignition system, which a stock 2002 doesn't have.  I suspect (but haven't confirmed) that using platinum plugs with an aftermarket high energy ign system will work out OK.  Soon as I get one of my old Delta Mk 10B CD systems working again I'll have to test that theory.

 

mike

[zinz]

NGK BP5ES or BP6ES. 

 

Where do you set your ignition timing? Incorrect timing or sloppy dizzy can cause incomplete burn and fouled plugs. Side drafts benefit from more ignition advance early in the curve. 

 

What type of air filter are you using? Make sure the bowl vent is not obstructed (recent thread had that vent blocked by the RamFlo backing plate)

 

Ed

[KFunk]

8 hours ago, antares242 said:

10 hours ago, KFunk said:

I’ve just been running good ole NGK BP6ES forever, I think. Around 11 years on DCOEs. The 5 is a little hotter and the 7 is a little colder if that’s what you want.  I’ve run the bp6es with stock cam and points, and now 292 with cranecam xr3000 with ps91 coil.  Can’t say if they’re perfect, but never given me any problems.

Thanks KFunk, would you say BP5ES would be drastically different if I want hotter?

I can’t remember too much, been some years since I thought about it and tried to tune it.   The 6s just did a decent bit better for me, but the 5s worked ok too.  I run BP7es in my air cooled Yamaha xs400 and those were a bit too cold for the 02.  

[wegweiser]

12 hours ago, antares242 said:

12 hours ago, Chris_B said:

First of all, I believe that the consensus is that 02s run best on the Bosch or NGK copper plugs. The Bosch W8 is already a pretty hot plug. Perhaps you should be looking to your carb tuning for a solution. Do you had a wideband 02 sensor/AFM?

No wideband or any of that. In regards of carb tuning, after lots of trial and error I found out that 65 F8 idle jets are the ones that allow me a wider range of mixture adjustment as I was previously using 55 F8s but those always tended to go on the lean side even if I had the mixture screws almost all the way out.. so long story short, I think I've found my ideal balance (not too lean not too rich) now but still my spark plugs go really black.. I'll attach some pictures soon! Thanks

Think about checking the current / or installing smaller chokes, for smoother transition / easier tuning. I've found 33 chokes to be a pretty good size for 2.0 motors with 9 or 9.5 compression. Add a little timing advance (use an adjustable timing light so you can document / repeat the setting accurately!) . That will lean out the mixture a bit as well. 

 

I no longer use ANY Bosch parts on my tii, unless i have no other option. The stuff is just junk these days. I swear by NGK BP5ES or BP6ES (the higher number denotes a COOLER plug when discussing NGK plugs. On my car, anything cooler makes cold starts / warm up a rough / miserable idle. 

Edited November 23, 2017 by wegweiser

[antares242]

Think about checking the current / or installing smaller chokes, for smoother transition / easier tuning. I've found 33 chokes to be a pretty good size for 2.0 motors with 9 or 9.5 compression. Add a little timing advance (use an adjustable timing light so you can document / repeat the setting accurately!) . That will lean out the mixture a bit as well. 
 
I no longer use ANY Bosch parts on my tii, unless i have no other option. The stuff is just junk these days. I swear by NGK BP5ES or BP6ES (the higher number denotes a COOLER plug when discussing NGK plugs. On my car, anything cooler makes cold starts / warm up a rough / miserable idle. 

Great tip, I'll try that, thank you!

[antares242]

I can’t remember too much, been some years since I thought about it and tried to tune it.   The 6s just did a decent bit better for me, but the 5s worked ok too.  I run BP7es in my air cooled Yamaha xs400 and those were a bit too cold for the 02.  

Thanks again man, I think to play safe I'll give BP6ES a shot

[KFunk]

Now that I’m thinking about it, I think with bp5es the spark plugs were just too whitish after running them a little bit, and cooling system was in good order.  The 6s got them all a nice tan without being too white.

[antares242]

Now that I’m thinking about it, I think with bp5es the spark plugs were just too whitish after running them a little bit, and cooling system was in good order.  The 6s got them all a nice tan without being too white.

That gives me more confidence. I just ordered a set on eBay

[antares242]

NGK BP5ES or BP6ES. 
 
Where do you set your ignition timing? Incorrect timing or sloppy dizzy can cause incomplete burn and fouled plugs. Side drafts benefit from more ignition advance early in the curve. 
 
What type of air filter are you using? Make sure the bowl vent is not obstructed (recent thread had that vent blocked by the RamFlo backing plate)
 
Ed

I did it myself, after tons of trial and error I think I got a sweet spot with a little advance. About the filters I'm using some redline metallic mesh style filters

[antares242]

NGK BP5ES or BP6ES. 
 
Where do you set your ignition timing? Incorrect timing or sloppy dizzy can cause incomplete burn and fouled plugs. Side drafts benefit from more ignition advance early in the curve. 
 
What type of air filter are you using? Make sure the bowl vent is not obstructed (recent thread had that vent blocked by the RamFlo backing plate)
 
Ed

I know it's off topic, but do you mean this style is no good? I was about to install it next week..

[zinz]

That filter is fine. It has a hole in the base plate ( by your thumb) for the bowl vent. They might not fit over the stacks, though. 

 

I take it that you are not using a timing light? ...you should. 

 

Which Webers are those? DCOMs? I see the vacuum lines coming off the back sides. Is your vacuum advance functional?

[antares242]

That filter is fine. It has a hole in the base plate ( by your thumb) for the bowl vent. They might not fit over the stacks, though. 
 
I take it that you are not using a timing light? ...you should. 
 
Which Webers are those? DCOMs? I see the vacuum lines coming off the back sides. Is your vacuum advance functional?

They're DCOE 45s. A while ago someone created a post on how to connect the vacuum lines from the dizzy to the carbs with silicone hose and m5 fittings that go into the vacuum holes of the carbs, so that's what I did and what you see right there. They came originally with those holes covered with screws. In regards to timing, the engine "feels" really fine but I'll get some light and check on that.

[TobyB]

BP6ES, here

 

I have had poor luck with any air strainer that interferes with the trumpets.  Or tries to form a tuned plenum.

 

I also think you're probably running a bit rich, but 'where' is always the tricky bit.  Thus, the wideband, for me...

 

t

[antares242]

BP6ES, here
 
I have had poor luck with any air strainer that interferes with the trumpets.  Or tries to form a tuned plenum.
 
I also think you're probably running a bit rich, but 'where' is always the tricky bit.  Thus, the wideband, for me...
 
t

Thanks Toby

[Oldtimerfahrer]

I have a very similar setup, 10:1 With 300 cam, 45dcoe with 38 chokes, 123 ignition and have been running the bp6es for years with good results. I only had one bad Bosch plug (bad out of the box). Put the Iridium plugs in last year, no comment on them yet. I do run 98 octane, never fouled the plugs despite rich mixtures and too much advance.

Andrew