Author Topic: Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey  (Read 7124 times)

3car fan

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« on: February 02, 2011, 02:55:52 AM »
New to Odysseys and to this site....Very cool forum!  My son just traded his Zooma Ty Rod 2 Kart for an FL250 Odyssey that needs engine work.  Just beginning to dig into it, but right off the bat I'm not understanding the reason for the "Sealing Bolt" hole next to the spark plug hole..??  And why would they make it the exact same size and threads as the spark plug hole if it wasn't meant for another spark plug?  The motor has compression but I haven't tested it yet.  It has the system with points and the wires from the magneto are not connected to the coil, so testing for spark is my first challenge.  Thanx in advance for any help.  We live near beaches with dunes so we can't wait to get it going!

hoodlum

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Re: Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #1 on: February 02, 2011, 08:48:00 AM »
Quote from: "3car fan"
New to Odysseys and to this site....Very cool forum!  My son just traded his Zooma Ty Rod 2 Kart for an FL250 Odyssey that needs engine work.  Just beginning to dig into it, but right off the bat I'm not understanding the reason for the "Sealing Bolt" hole next to the spark plug hole..??  And why would they make it the exact same size and threads as the spark plug hole if it wasn't meant for another spark plug?  The motor has compression but I haven't tested it yet.  It has the system with points and the wires from the magneto are not connected to the coil, so testing for spark is my first challenge.  Thanx in advance for any help.  We live near beaches with dunes so we can't wait to get it going!


Not up to par on the 250,but if i'm not mistaken,the head was used on another machine produced by Honda that incorporated the other hole....When used on the 250,it was not needed so it was plugged......
Hoodlum

3car fan

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #2 on: February 02, 2011, 12:31:48 PM »
Thanx Hood, that makes sense!

1982fl250c

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #3 on: February 03, 2011, 09:29:27 PM »
Quote from: "3car fan"
Thanx Hood, that makes sense!
hi the head is of a 2 stroke motorcycle engine from 1970s some people do add a douple wire coils and add 2 spark plugs it will give more spark..! but will not give you more power :lol:

1982fl250c

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #4 on: February 03, 2011, 09:29:55 PM »
Quote from: "1982fl250c"
Quote from: "3car fan"
Thanx Hood, that makes sense!
hi the head is off a 2 stroke motorcycle engine from 1970s some people do add a douple wire coils and add 2 spark plugs it will give more spark..! but will not give you more power :lol:

3car fan

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #5 on: February 03, 2011, 10:22:20 PM »
Thanx '82...Cool to know the history.  Yeah, from what I understand running 2 plugs is more of a emission control thing, allowing for a more complete burn in extremely lean or rich mixtures.  As for higher performance they say you would need separate the timing for each spark plug....sounds like more than I'm willing to deal with right now.  What I would really like to know is if I can check for spark off the 2 wires coming off the magneto.  In my situation they are not connected to anything.  I assume they connect directly to the coil but not sure at this point.

hoodlum

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #6 on: February 04, 2011, 08:07:05 AM »
Maybe this will help.....

http://aftershockmotorsports.com/manuals/Honda/FL250-Odyssey/Honda-FL250-Odyssey-Manual.pdf

Looks like the black wire goes to the black wire on the coil,and the yellow wire goes to the light switch to provide power to the head light....

Hoodlum

3car fan

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Reason for "Sealing Bolt" or 2nd spark plug on FL250 Odyssey
« Reply #7 on: February 04, 2011, 04:19:31 PM »
Wow....thanx Hood, that's a Huge Help!  A shop manual...freakin awesome!