b7evx plug question?

Need some help? Put your question up here. Many years of experience on the board to help you get up and running.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
Eddie
To the on ramp
Posts: 280
Joined: Fri Oct 19, 2012 9:57 am
Country: U.S.
Suzuki 2-Strokes: 1974 gt750, 1963 superhawk

b7evx plug question?

Post by Eddie »

well, im in the process of putting the newtronics kit on the bike, but before I did that I found a set of ngk b7evx platnum plugs for the bike, before I had put them in I had regular b7es plugs, and i had been adjusting the oil pump to its max to see if the bike was getting oil, well I foulled the plugs so i would say yes its getting oil, so then I put the b7evx plugs in and adjusted the oil pump to the normal setting and now the bike smokes? what the hell? I check the plugs and they are black like they are to rich except the far left plug, its lean? I will check the carbs but it was not like this when i had the b7es plugs in, so the question is,,,,when i got the b7evx it said they were non resistor plugs so I got them ( i have stock plug caps) and now the bike smokes? and plugs look rich? but with the regular b7es the plugs look lean? what the hell? any thoughts? I will look at carbs but like i said it looked lean with b7es and now rich and smokes with the b7evx? and i checked it with both plugs without messing with the carbs, so i guess its the plugs? are they colder than the b7es? I know the 7 is the heat range but this is weird?
Craig380
Expert racer
Posts: 1254
Joined: Mon Dec 01, 2008 2:52 am
Location: Manchester, UK

Re: b7evx plug question?

Post by Craig380 »

It's hard to accurately gauge richness / lean-ness with brand-new plugs, they take a while to get a colour. Also, it will be smoking because it's firing the mixture and cleaning all the oily crap out of the cases, not fouling the plugs ...
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
User avatar
jabcb
Moto GP
Posts: 4311
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: b7evx plug question?

Post by jabcb »

An explanation of the plug names is here: http://www.ngksparkplugs.com/docs/tech/ ... _plugs.pdf

The B7EVX are discontinued. Suggest you buy some spares if you decide you like them.
The B7EV is similar -- might also consider getting some spares of these since they are discontinued.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Eddie
To the on ramp
Posts: 280
Joined: Fri Oct 19, 2012 9:57 am
Country: U.S.
Suzuki 2-Strokes: 1974 gt750, 1963 superhawk

Re: b7evx plug question?

Post by Eddie »

Thanks for the info!, I was wondering if any of you had tried the b7evx and if so did you like them? i ran the bike for a few miles and she started running funny then i pulled the plugs and they were black, very black so maybe theres another issue going on?, well when I finish the newtronics kit and test run i will report back, thanks for the help.
pearljam724
AMA Superbike
Posts: 1681
Joined: Tue Jul 24, 2012 11:45 pm
Country: U.S.
Suzuki 2-Strokes: 75- GT 550 / 76- GT 750
Location: SW PA

Re: b7evx plug question?

Post by pearljam724 »

I tried the fine wire plugs. I do not like them, they foul very easily.
Image Image
User avatar
tz375
Moto GP
Posts: 6211
Joined: Mon Nov 03, 2008 10:47 am
Location: Illinois

Re: b7evx plug question?

Post by tz375 »

Interesting results. the advantage of a fine wire plug is that it is less likely to foul than a standard wide electrode. I use BR9EIX Iridium plugs with a slightly non-standard set up. Mine runs very high compression and a DYNA S ignition and a relay to make sure that no volts are lost going through the stock wiring and connectors.

Big fat blue sparks and no hint of a misfire even when the cases were half full of oil from leaking check valves. Maybe a stock ignition system cannot generate sufficient voltage to fire a fine wire plug consistently.
pearljam724
AMA Superbike
Posts: 1681
Joined: Tue Jul 24, 2012 11:45 pm
Country: U.S.
Suzuki 2-Strokes: 75- GT 550 / 76- GT 750
Location: SW PA

Re: b7evx plug question?

Post by pearljam724 »

That may be true, Richard. I noticed much easier starts, better idle, etc. On my bike though, it's very hard to keep them clean and my pump is turned down very far. Im going to try them on the 750 being I will have aftermarket coils on it and see how they act.
Image Image
Post Reply