• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Second set of dead spark plugs?

  • Thread starter Thread starter Jackw
  • Start date Start date
J

Jackw

Guest
finally got the 550 running, for a bit anyway. Then plugs 3 and 4 went dead(they were new plugs). Changed those 2 out now I just went to start it and plugs 2, 3, and 4 will not fire. but the one good plug fires on all 4 wires? can it be I just got bad plugs twice? can a coil problem kill a plug? resistance acrossed plug wires was 26 Kohms and 3.8 ohms acrossed the power connector? Any Ideas. I'm just about ready to part her out!!
 
Are the plugs oil fouled or carbon? And no, you did not get "bad plugs". The problem is somewhere on your particular bike. What is the condition of your air filter?
 
Jackw said:
yes plugs do seem to be oil fouled. Air filter is new....
Click to expand...

Oil fouled means you need to do a compression test. You may have bad rings. Don't guess on what could be wrong, measure to determine where possible.
 
compression is between 120 -140 on all cylinders. I had it out the other day and it was working awesome. What would cause those plugs not to fire acrossed the gap? they are sparking to the head but not acrossed the gap. Can bad coils or ignitor kill a plug?
 
Battery is charged, it's turning over the way it should be. The one plug that is still firing, fires properly on all spark plug wires. When the first 2 plugs went dead on cylinders 3 & 4 I changed them out, I also changed the spark plug caps at that time. I have good spark from the coils with no plug caps on. Now the plugs in cylinders 2,3 &4 are fried. Bike gets lots of fuel, new air filter installed. Valves were set by a mechanic. but I'm thinking of checking the valve clearances again for good measure. there wasn't much on the plugs just a bit of black on them which wipes right off on my fingers. does this sound like an electrical problem. I know that fuel and air are good! can the coils still be screwed up even though the resistances are in spec?

Thanks to all in advance....
 
Last edited:
ok, so the plugs are good, but they were oil fouled. Compression is good, so I guess it's time to check the valves??
 
Oil fouled plugs indicate oil is leaking into the combustion chamber. Obvious choices include bad oil control piston rings or leaking valve stem seals. Don't mean to doubt you but it more likely that you have an ignition problem of some sort. Considering how the problem effects all the plugs I'd suspect the ignitor. Not sure though. You really need to understand if the plugs are truly oil fouled. After that you can make an informed plan of action.
 
New plugs CAN be bad. I know because I just had one. New NGK B8ES properly gapped began to misfire after about 2 minutes of running. I thought, "No, I can't be a bad new plug",so I checked everything else electrical first including checking points, cleaning up all the wire connections and ground connections, and swapping out for a known good coil. Nothing worked so I swapped the plug to another cylinder and that cylinder misfired too. Replaced the plug and it runs fine now.

The plug was sooty black but not oil fouled. The primary and secondary resistance of the coils were very similar to what you found.

Go for new plugs. NGK may have let some bad ones slip through QC.

Good luck
 
I cleaned up the plugs by brushing them lightly with a wire brush, and now all the plugs have a nice blue spark on every wire. I spoke with a guy who does small engine work up the road from me and he said to check the valves. the valves were set by a mechanic, but if they were not set properly can this let oil into the chamber? The bike was working pretty good before the valves and Carbs were done. I have checked the carbs though and gas is flowing well.
I don't think it's the ignitor, but I guess it could be.
I checked just the plug wire with no cap and get a nice fat blue spark in every wire. I just put brand new NGK plug caps, and again get good spark on all plugs once they are cleaned up. there is definately oil getting into the chamber.

so really right now I guess I need to know the following:

if valves are out of adjustement can this allow oil to get into the chamber?
Can I have compression over 120 and still have enough blow by to fould the plugs?
will leaking valve stem seals let oil run into the chamber while it's sitting? I assume yes...
and if I'm way off on any of this feel free to set me straight.

Thanks for all the help from the experts on this site, without you guys I'd be selling parts on ebay right now...
 
Jackw said:
so really right now I guess I need to know the following:

if valves are out of adjustement can this allow oil to get into the chamber?
Can I have compression over 120 and still have enough blow by to fould the plugs?
will leaking valve stem seals let oil run into the chamber while it's sitting? I assume yes...
and if I'm way off on any of this feel free to set me straight.

Thanks for all the help from the experts on this site, without you guys I'd be selling parts on ebay right now...
Click to expand...


Leaking valve stem seals tend to allow oil to seep down into the combustion chamber when the engine is sitting and during deceleration when vacuum is high. Do you have a lot of blue smoke out the exhaust on a cold start and during deceleration? Is the engine burning a good bit of oil?
 
there is some blue smoke on a cold start. And the bike was stalling sometimes when stopping at red lights, but it would start right up again. I never noticed blue smoke on deceleration. Looks like I got some digging to do.

If the compression is over 120 on all cylinders is it possible to still have enough blow by to foul the plugs?
If the valves are out of spec can this allow oil into the chamber? or is it only the seals that will cause this?
 
Jackw said:
there is some blue smoke on a cold start. And the bike was stalling sometimes when stopping at red lights, but it would start right up again. I never noticed blue smoke on deceleration. Looks like I got some digging to do.

If the compression is over 120 on all cylinders is it possible to still have enough blow by to foul the plugs?
If the valves are out of spec can this allow oil into the chamber? or is it only the seals that will cause this?
Click to expand...


120 is not too bad. Your rings are valves are sealing fairly well. Oil control is another matter though. The valve stem seals get hard over time and maybe some of yours are cracked? Not sure. As the engine wears the clearance between the valves and the valve guide increases, more so on engines with rockerarms like yours (you have the 16v engine right?). Extra clearance allows oil to leak down. Oil control rings also can get gummed up, reducing their effectiveness which is unrelated to the compression rings (although they tend to wear together). Not sure this helps any other than spell doom and gloom. Sorry. One trick to try to free up a stuck oil control ring is to put some Marvel Mystery Oil in the cylinder and let it soak for a couple of days. Other than that I have no ideas other than pulling the head/cylinder and measure everything to see what the real problem is.

Good luck.
 
You must log in or register to reply here.
Back
Top