Need some education on NGK heat ranges. Need a 3/8" reach GAS NGK plug for the open 101 with a Mc20 head. I'm currently running B8S alky plug. What's the equivalent gasoline plug? Thanks in advance. Ted
Re: NGK gas plugs
Posted: Fri Sep 10, 2010 4:26 pm
by Jeff Campbell
Ted,
I've been running NGK B8S plugs in all my older 3/8" reach head "gas" McCulloch engines.
For what it's worth, at TBO, I ran out of B8S plugs, and only had NGK B8HS plugs left (they are 1/2" reach), luckily I had some of those copper "indexing washers" which are handy to have, two of those under a 1/2" plug converts it to a 3/8".
Jeff
Re: NGK gas plugs
Posted: Fri Sep 10, 2010 4:48 pm
by ted johnson
Thank you, Jeff. Bonbright suggested B7S or even B6S. Need to get both the B*S and the B*HS, as the Mac uses 3/8" reach, and the 610 uses 1/2" reach. I've decided to go with gas and no more purging! Maybe with stock HR carbs, I can get the engines to take fuel on the top end . TJ
Re: NGK gas plugs
Posted: Fri Sep 10, 2010 5:31 pm
by Jeff Campbell
Ted,
Yes, maybe a notch hotter plug (with NGK, the lower the number, the hotter the plug) could work, especially if you aren't pushing the motor to the limit while driving it. I run my motors really hard, and those B8S plugs come out chocolate brown.
Re: NGK gas plugs
Posted: Fri Sep 10, 2010 8:54 pm
by ted johnson
Thanks again, Jeff. I'll get some B7S and B7HS from eBay. That oughta do it. Terry is sending a couple of HR gas carbs when he sends my Mc5 cylinder, so I'll be set. TJ
Re: NGK gas plugs
Posted: Mon Sep 13, 2010 8:32 am
by stan wauthier
Ted,
I think you"ll be very happy with the HR carbs. I ran a HR-181 on my single WB820 for the first time this year (made my own intake manifold for it) and I was surprised with how well it ran throughout the full range at TBO. I ran it on gas at Thompson a few weeks prior to TBO and was running fat. Kept turning the screws in and got a little concerned with the settings to get it tuned in. At TBO I ran E85 and WOW! Just as good as running Methanol. However with E85 I still flushed it out at the end of the day.
Re: NGK gas plugs
Posted: Mon Sep 13, 2010 10:36 am
by ted johnson
Thanks, Stan. Fun time at TBO this year! Funny thing, I've never run an HR Tilly; I started out in the early seventies with a 34mm Mikuni (Burco Supercarb) that Chuck West's father modified for me, and I've had them ever since. Terry is sending a pair of HR's, and we'll try them out. TJ
. TJ