Oiling up one plug, starts ok but constantly misfires

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bluemarlin
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Oiling up one plug, starts ok but constantly misfires

#1

Post by bluemarlin » Tue Jan 06, 2004 8:08 pm

i took my new bike out for the first time today it ran ok for about ten miles and then started misfiring. i managed to make it home and on inspection it seems the front pot is oiling up.so far i have changed, the coil,plugs,points,,condenser and checked the timing .no difference the bike starts ok but constantly misfires the front pot is cold compared to the rear. i have done a compression test 100psi on both pots,it is a 58 bottom end shovelhead heads. what do you reckon?



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Re: Oiling up one plug

#2

Post by panhead » Tue Jan 06, 2004 8:15 pm

Have you used new plugs?

dereborn
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Re: Oiling up one plug

#3

Post by dereborn » Tue Jan 06, 2004 9:03 pm

Have you checked that you actually have a spark from the front plug? You know, plug removed but with cable on, contact w jug, ignition on and kick it once or twice. The spark should not just appear, but be bright and blue!

MUTT
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Re: Oiling up one plug

#4

Post by MUTT » Tue Jan 06, 2004 11:11 pm

Not to but in but you dont have to kick it over. remove the point cover and open and close the points with a screwdriver. its alot easyer than kicking it"Oiling" or sooting???

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Re: Oiling up one plug

#5

Post by Cotten » Wed Jan 07, 2004 12:43 am

The last replies suggest ignition problems. Such a problem would produce a dry soot. Or at least dry up on the bench.
If it is truly oily, then you have a mechanical problem.

Beyond ignition, the most common reason of one plug to soot more that the other is because the carb has been adjusted for a lean cylinder. In other words, an Evil Manifold Leak. I think I'll just start typing EML.

Chubble manifolds are some of the trickiest to seal properly. That's why pans rule. (And bless-ed Knucks and Flatties of course!)

So that's the easy-to-fix scenario. Just pressure test it with soap.
It gets much worse if its truly oily.
I won't get int that unless we have to. Let us know.

bluemarlin
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Re: Oiling up one plug

#6

Post by bluemarlin » Wed Jan 07, 2004 1:21 pm

both plugs sparking well the front plug is oily i suspect something nasty

dereborn
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Re: Oiling up one plug

#7

Post by dereborn » Wed Jan 07, 2004 1:31 pm

Cotten, if there is no spark at all in the front jug (it was cold, right?) the plug would be wet, not dry and sooty, would it? At least I thought so.
And of course your checking procedure is easier Mutt!

bluemarlin
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Re: Oiling up one plug

#8

Post by bluemarlin » Sat Jan 17, 2004 3:58 pm

bike up and running ok. new manifold rubbers seem to have done the trick.thanks for all the advice

Topsy

Re: Oiling up one plug

#9

Post by Topsy » Sat Jan 17, 2004 9:52 pm

I have the same problem on my 56. I think it's a leaky valve guide, but I would love somebody to tell me different (cheaper fix). Is your front pipe smoking, or worse still oily too? if so it's probably the same problem as I have in which case when I get mine replaced I may have the answer.

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Re: Oiling up one plug

#10

Post by Cotten » Sun Jan 18, 2004 1:29 am

We seem to have a lot of confusion over what is an oily fouled plug, and what might only be a sooty plug.
Let it sit on the bench or in the sunlight for a good while. If it still keeps a wet appearance... and wipes onto your finger quite greasy,,,, yer facing grief.

If it gets dry, and the black wipe on your finger is powdery, then it is fuel fouled and can hopefully be remedied before damage is done.

This is an oversimplification of course.

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Re: Oiling up one plug

#11

Post by dereborn » Sun Jan 18, 2004 11:54 am

Cotten - you ever considered teaching? That's what I meant in my last post, only I couldn't put it as simple...
I use the same diagnose method, only with the tip of my nose instead of the finger... If it smells of fuel, and isn't very thick'n'sticky it's not that bad. The black spot on the nose also tells the difference, if its shiny -it's bad, if its dry - no danger.

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