Penton Owners Group

General Discussion => Penton Talk => Topic started by: stumpjumper on June 17, 2016, 05:45:43 AM

Title: plug
Post by: stumpjumper on June 17, 2016, 05:45:43 AM
have my mint 400 completed and put back together.put pvl ignition in it.does anyone know what spark plug to use with that ignition.was told ngk b8ev or its crossreference.cant remember for sure had one in the 70s does it take a long shank or short shank.havin a heck of time getting it started checked spark and is getting gas.wearing me out!


rich skeweris
Title: plug
Post by: 454MRW on June 17, 2016, 08:20:51 AM
Rich,
You should read section 7 about spark plugs in the pvl instructions available on the web. It recommends fine wire or precious metal spark plugs and it requires a higher cranking speed to generate sufficient spark for starting than a Motoplat, and those plugs required less voltage. You should call Penton racing for their recommendations on specific spark plugs which would work best and timing for your Mint 400. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico
Title: plug
Post by: Larry Perkins on June 17, 2016, 09:25:40 AM
If memory serves me right on my Mint 400s I used a B8HV for Cross Country and a B9HV for motocross.  You do not want an E plug as that is long reach and the piston will hit it.  What you want is a short reach or H series in an irridium plug.  But M9ike is right check with Penton Racing to be certain as I am quoting from old memory.  Unfortunately it has been awhile since I had a Mint.

Larry P
Title: plug
Post by: gooddirt on June 17, 2016, 03:19:51 PM
Got to find old stock on the B8HV, its no longer made.Or  get the  NGK 7383 racing or your B8HS standard.
Title: plug
Post by: brian kirby on June 17, 2016, 08:47:10 PM
I seriously doubt the plug is your problem, I use the B8HS thick wire plug in all my bikes, which PVL explicitly says not to use, and my bikes start and run fine. The key with the 400, or any big bore two stroke for that matter, is you cant just kick it where ever it is in the crank rotation. You must inch the crank to just barely past TDC and then recock the kick lever and kick it like you mean it, making sure you get a full complete stroke of the lever. Unless you are a fairly large person you cant just stab at the kicker, you wont generate enough crank speed for it to start.

Brian
Title: plug
Post by: stumpjumper on June 18, 2016, 06:35:11 AM
Thanks brian will try that.

rich skeweris
Title: plug
Post by: brian kirby on June 18, 2016, 07:43:12 AM
The 400 has a compression release on the back of the cylinder also, most bikes just have a block off plug. If your bike does not have one installed see if someone here has the valve, having a functioning compression release makes a big difference on the 400.

Brian
Title: plug
Post by: marsattacks on June 18, 2016, 09:17:00 PM
What Brian said. Plus if you have a Bing carb then flood the snot out of it.  Maybe get on a small step or something for good leverage and give a firm, smooth and non-abusive stroke.  Post a vid when she's running!
Title: plug
Post by: 454MRW on June 17, 2016, 08:20:51 AM
Rich,
You should read section 7 about spark plugs in the pvl instructions available on the web. It recommends fine wire or precious metal spark plugs and it requires a higher cranking speed to generate sufficient spark for starting than a Motoplat, and those plugs required less voltage. You should call Penton racing for their recommendations on specific spark plugs which would work best and timing for your Mint 400. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico
Title: plug
Post by: Larry Perkins on June 17, 2016, 09:25:40 AM
If memory serves me right on my Mint 400s I used a B8HV for Cross Country and a B9HV for motocross.  You do not want an E plug as that is long reach and the piston will hit it.  What you want is a short reach or H series in an irridium plug.  But M9ike is right check with Penton Racing to be certain as I am quoting from old memory.  Unfortunately it has been awhile since I had a Mint.

Larry P
Title: plug
Post by: gooddirt on June 17, 2016, 03:19:51 PM
Got to find old stock on the B8HV, its no longer made.Or  get the  NGK 7383 racing or your B8HS standard.
Title: plug
Post by: brian kirby on June 17, 2016, 08:47:10 PM
I seriously doubt the plug is your problem, I use the B8HS thick wire plug in all my bikes, which PVL explicitly says not to use, and my bikes start and run fine. The key with the 400, or any big bore two stroke for that matter, is you cant just kick it where ever it is in the crank rotation. You must inch the crank to just barely past TDC and then recock the kick lever and kick it like you mean it, making sure you get a full complete stroke of the lever. Unless you are a fairly large person you cant just stab at the kicker, you wont generate enough crank speed for it to start.

Brian
Title: plug
Post by: stumpjumper on June 18, 2016, 06:35:11 AM
Thanks brian will try that.

rich skeweris
Title: plug
Post by: brian kirby on June 18, 2016, 07:43:12 AM
The 400 has a compression release on the back of the cylinder also, most bikes just have a block off plug. If your bike does not have one installed see if someone here has the valve, having a functioning compression release makes a big difference on the 400.

Brian
Title: plug
Post by: marsattacks on June 18, 2016, 09:17:00 PM
What Brian said. Plus if you have a Bing carb then flood the snot out of it.  Maybe get on a small step or something for good leverage and give a firm, smooth and non-abusive stroke.  Post a vid when she's running!
Title: plug
Post by: stumpjumper on June 19, 2016, 07:48:05 PM
really appreciate the help run one of these for 3 years in the 70s.forgot how hard they were to start.havent tried drifting it yet hoping it would start by cranking first fresh motor!gotta stand on a stool to crank it have had a couple knee replacements think he made me shorter!lol.


rich skeweris
Title: plug
Post by: Kip Kern on June 20, 2016, 07:13:24 AM
W3AC standard, W3AS racing Bosch.  Gap at .022
Title: plug
Post by: chicagojerry on June 20, 2016, 02:45:39 PM
rich (stumpjumper) i sent you a private email through this message board. i hope that you get it. chi jer
Title: plug
Post by: 454MRW on June 20, 2016, 03:06:41 PM
What a lot of Penton owners have learned over the years that new or renewed owners may have overlooked, is that Pentons, especially with KTM engines like a lot of fuel too fire off. Those with Bing carbs work best starting by holding the tickler down until fuel runs out the overflow before kicking It. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico
Title: plug
Post by: gooddirt on June 20, 2016, 07:29:00 PM
Got the extra flywheel weights ? hope so ...
Title: plug
Post by: stumpjumper on June 21, 2016, 06:18:58 PM
yea haven't taken time to try it for a few days will get back to it.yea usually tickle carb till gas runs out.dont have no flywheel weights.chicago jerry told me about the head mod should have done that before putting back together.we will see!


rich skeweris
Title: plug
Post by: stumpjumper on July 04, 2016, 06:18:54 PM
well back at it again for a bit.fulled with the timing a little.can get it to fire at one point.but wont take off.had the carb rebuilt just wondering if it might be getting too much gas.tickle it until gas runs out I remember all that from years ago.but wont take off.take plug out its wet.clean it and check spark and when you get a good crank on it pretty blue sparks.tried pulling finally got it to fire a little well it had rained wheel locked up pulled me into slide now got a little road rash and thank god the bike didn't get hurt!lol!just glad I can laugh about it.bout got me wore out!makes me fell like a dummy no there is not to many thing it could be.


rich skeweris
Title: plug
Post by: 454MRW on July 04, 2016, 06:59:57 PM
One thing you might check is that in case of the floats being a little high and it getting gas in the crank case is to pull out the Allen bolt directly below the crankshaft and drain the crank case of fuel. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico
Title: plug
Post by: stumpjumper on July 04, 2016, 08:08:57 PM
Thanks mike!

rich skeweris