93 K75 engine problem

[TechPoet]

I've been having intermittent problems with the 93 K75. I was riding along and the engine began to choke, sputter, lose compression, even backfire. I would twist the throttle and the bike would buck like... Something was wrong.

These problems started the day that I changed both the oil and then the spark plugs.

I make it to a BMW shop they keep it a few days then tell me it's fixed. That it was a loose spark plug cap. Ouch!

Two days later, same engine behavior. I barely escape the freeway and sputter up to a gas station. I futz around with the spark plug wires but they weren't loose. I took the wires off a few times but didn't take out the plugs. It started running fine again and seemed fine for a few days.

The guy at the shop said, "I don't know... Maybe an electrical glitch somewhere in the system." [ :(?]

Today it  wouldn't "fix itself". So I finally got motivated to remove the spark plugs. The electrodes were black and oily. I got a bit of gas on a rag and cleaned them up a little bit. At first the bike seemed the same but I kept revving and finally the crap got burned off (guess) and voila!

Later, as I describe this to a buddy he asks, "you changed oil and plugs the same day, eh? Did you put in too much oil?"

Well, yes.  (Actually I found out that the 4qts specified is too much.)http://www.motobrick.com/index.php/topic,4123.0/topicseen.html


So I am going to proceed on that assumption.

1. How can I best reverse the foul up from too much oil in the K bike?

2. Should this bike have Bosch X5DC or X R 5DC plugs?

[cy7878]

Since the bike was running well before the plug and oil change, I would agree with you that one or both of the procedures caused the problem.


1. Now, obviously you have since drained the excess oil, right?

2. the loose plug wire may need to be changed because poor electrical connections can cause arcing and lead to poor conduction.  I learned this the hard way with my car's battery terminals.  You may be able to clean it with wire brushes, but check the metal contacts to see if they are nice and "metallic"

3.  The plug may be fouled because it's not getting spark/electrical current.  problem may still be the wire (#2).  If the plug is fouled, you have to change it for obvious reasons.

I would try these things first as they are simple, inexpensive and see what happenes.  As for too much oil, I actually doubt that was your problem.  From what I can see in my K100, too much oil will probably leak out of the main seals since the lower lip of the seal is just at the top level of the oil glass....

[Chaos]

X5DC are the correct plugs.  If you used the XR5DC I'm guessing those are the resistor version, which may be causing you problems.  K75's have built in resistance in their wires.  Doubt that overfilling a little would cause problems unless you left it on the sidestand, but then it would probably foul plugs on start up.  At least mine does.