Spark plugs foul every time

WillP · Full Member Joined: Dec 22, 2008 Posts: 46

I have a 71 xs650. Every time I ride it the plugs foul completely: I am using NGK B7es and the chilton suggests running a hotter plug.
I have to clean the plugs every time I want to ride and sometime it is up to a month between rides. Why so much oil in the engine and what can I do?

yamaman · Posted: April 26, 2009, 4:39 pm Post subject: Re: Spark plugs foul every time

I would have thought a BP8ES would be the correct plug for your bike, thats one colder than a B7ES.

Not sure who chilton is, isn't that a town in Victoria?

kingwj · Posted: April 26, 2009, 5:32 pm Post subject: Re: Spark plugs foul every time

Chilton is a repair manual similar to Haynes. Isn't that a rotten English cheese? No, that is Stilton.

To the OP- does the bike belch white smoke? I would think smoke would be present to foul plugs so quickly. It might be gas fouling, a much better problem to face.

xsjohn · Posted: April 26, 2009, 5:34 pm Post subject: Re: Spark plugs foul every time

Maybe the PO richened the carbs or moved the needle clip from it's recommended position.........7's would be right.........8's could take miles to clean off after a cold start if ever.....xsjohn

Needle position 4 (Down from the top) factory setting
130MJ
pilot jet 45
mix screw one turn out
float 25MM

jayel · Posted: April 26, 2009, 5:39 pm Post subject: Re: Spark plugs foul every time

I run BP8ES's in my 74TX650 but then again I'm not running a 8:1 loafer meter maid motor

pumps · Posted: April 26, 2009, 5:47 pm Post subject: Re: Spark plugs foul every time

Check compression would be a good place to start I would think. Only two place I can think of that you could get oil on the plugs. Past the rings or past the valves.

kingwj · Posted: April 26, 2009, 6:11 pm Post subject: Re: Spark plugs foul every time

jayel wrote:

I run BP8ES's in my 74TX650 but then again I'm not running a 8:1 loafer meter maid motor

slap. I await John's reply, should be any second now.

WillP · Full Member Joined: Dec 22, 2008 Posts: 46

If it is compression, what then? Rebuild the entire engine?

jayel · Posted: April 26, 2009, 7:32 pm Post subject: Re: Spark plugs foul every time

depends if it's rings or valves, best thing to do is have a leak down test done, maybe 20 bucks to have it checked, that will check the compression holding ability of the rings or valves but it won't tell you any thing about the valve guides which is where the oil could be coming from

xsjohn · Posted: April 26, 2009, 8:04 pm Post subject: Re: Spark plugs foul every time

"""""""I'm not running a 8:1 loafer meter maid motor"""""""

Well I was out riding on my metro meteor while you girls were having your little backroom chat..... Laughing

xsjohn

WillP · Full Member Joined: Dec 22, 2008 Posts: 46

jayel wrote:

depends if it's rings or valves, best thing to do is have a leak down test done, maybe 20 bucks to have it checked, that will check the compression holding ability of the rings or valves but it won't tell you any thing about the valve guides which is where the oil could be coming from

Thanks Jayel. I will try to find a place around here that does those test. Problem is, I kicked and kicked today and used starter fluid but could not get the bike started. Clean spak plugs too and gas. Lost cause?

jayel · Last edited by jayel on April 29, 2009, 8:11 am; edited 1 time in total

get the compression checked or a leak-down test first then you'll know enough to start making decisions on what to look at next, low compression makes for hard starting, might be a good idea to set the valves before testing,

on a cold engine remove the four valve covers, the sparkplugs, cam chain adjustment nut (22mm I think but a 7/8" will work also), and the alternator cover on the left side, rotate the engine using a 17mm box end wrench on the alternator rotor nut anti-clock wise, watch the little plunger in the cam chain adjuster when it goes in, the slack of the chain is at the rear of its run, adjust the outer tensioner so it is flush with the tensioner plunger,

rotate the engine a few turns using the 17mm wrench on the rotor nut to make sure it's correct (ending up flush with the adjuster when it goes in ) and re-install adjuster nut, now to set the valves, rotate the engine anti-clockwise until the "T" on the Stator and the line on the rotor line up the pistons are now at TDC (top dead center) one cylinder will be on its compression stroke,

feel the rocker arms, one side should be slightly loose, check the clearances, intake should be .003 and exhaust .005 (I'll get some argument here, but these are close enough for now), the lock down nut is a 10mm and the little square set screw adjuster is a 4mm, after checking and setting the valves on that side rotate the engine using the 17mm wrench on the rotor nut again anti-clockwise 360 degrees back to the "T" this will bring the second cylinder up to TDC on its compression stroke,

set its valves the same way as the first and you're done

WillP · Full Member Joined: Dec 22, 2008 Posts: 46

Thanks a ton Jayel. I will try setting the valves after I get the tools and get the permission slip for the all day hobby day from the wife.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

deleted

NateDogg · Posted: May 25, 2009, 7:33 pm Post subject: Re: Spark plugs foul every time

What about timing advance/retard, when I was still runing that peice of crap mechanical advance it would foul plugs all the time

xsjohn · Posted: May 25, 2009, 7:49 pm Post subject: Re: Spark plugs foul every time

If and when it gets to 135 cranking compression it will take the next hotter plug with no problems......considering the main jet is the right size.......by then the stock is usuallt right also.......

xsjohn

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