1 Plug Identification Tue Apr 21, 2020 10:39 pm
Rockymountainmoto
active member
Hello!
I have a 1985 BMW k100 that started to run really poorly recently. It was overdue for some maintenance since i bought it, so i decided to use this opportunity to fix some things, and conduct some preventative maintenance.
Through my testing, i've found a few issues:
1. 2-3 coil had no resistance between the high voltage towers, the 1-4 coil had 10.5 ohms. Both coils had 2.5 at the low voltage plugs. Coils were the original old black versions. Just ordered some new red tops.
2. Fuel pressure bounced around significantly when i tested it, but stayed between 35-39 psi. Upon shutting off the bike, the pressure dropped to 0 almost immediately. Fuel pump and filter have been replaced fairly recently. I took this to mean an issue with stuck injector/FPR. I've ordered the new 4 hole version of the injectors, and a new FPR to eliminate any issues with the fuel system.
3. installed a new air filter, checked the paddle in the sensor while i was doing so and it moved freely.
4. The z crank case breather hose was cracking, but didn't look like it had cracked all the way through yet, I went ahead and ordered a new one. There was a little bit of oil in the hose when i removed it. I wasn't sure if this is normal.
5. the hose connecting the bottom of the FPR and cylinder 4 was in mediocre shape, but didnt have a clamp on it where it connected to the cylinder. I've ordered a new one, but does it need to be clamped?
6. bought and will install a new HES.
7. when i removed the top of the reservoir for the rear brake, there was only half the fluid left from when i topped it off a year ago. I went ahead and got a new reservoir and new rear brake lines. Hopefully thats the issue and i don't have to rebuild the caliper or cylinder.
Anyway
I'm continuing to test the bike as i go. It's never run great (i've had it for 3 years, but never had a chance to dive into it til now), it always seemed to stumble on itself if given gas too quickly, and has progressively idled worse, until it started to noticeably hunt in idle which is why i've started this process.
Anyway i live at 7k elevation, and came across some information about a high altitude plug on the bike. I've looked and looked and cannot find it. However I did find a plug that had been disconnected, and a plug with no connection to it. I'm trying to figure out what each of these plugs do(thinking one could be the high altitude plug)?! both have been unplugged since i bought it, so I'm interested in finding out how they affect the bike.
Here are two pictures of the plugs. The top three prong plug was unplugged when i found it.
The bottom two prong plug has not mate, and i'm assuming this is the high altitude plug?
I have a 1985 BMW k100 that started to run really poorly recently. It was overdue for some maintenance since i bought it, so i decided to use this opportunity to fix some things, and conduct some preventative maintenance.
Through my testing, i've found a few issues:
1. 2-3 coil had no resistance between the high voltage towers, the 1-4 coil had 10.5 ohms. Both coils had 2.5 at the low voltage plugs. Coils were the original old black versions. Just ordered some new red tops.
2. Fuel pressure bounced around significantly when i tested it, but stayed between 35-39 psi. Upon shutting off the bike, the pressure dropped to 0 almost immediately. Fuel pump and filter have been replaced fairly recently. I took this to mean an issue with stuck injector/FPR. I've ordered the new 4 hole version of the injectors, and a new FPR to eliminate any issues with the fuel system.
3. installed a new air filter, checked the paddle in the sensor while i was doing so and it moved freely.
4. The z crank case breather hose was cracking, but didn't look like it had cracked all the way through yet, I went ahead and ordered a new one. There was a little bit of oil in the hose when i removed it. I wasn't sure if this is normal.
5. the hose connecting the bottom of the FPR and cylinder 4 was in mediocre shape, but didnt have a clamp on it where it connected to the cylinder. I've ordered a new one, but does it need to be clamped?
6. bought and will install a new HES.
7. when i removed the top of the reservoir for the rear brake, there was only half the fluid left from when i topped it off a year ago. I went ahead and got a new reservoir and new rear brake lines. Hopefully thats the issue and i don't have to rebuild the caliper or cylinder.
Anyway
I'm continuing to test the bike as i go. It's never run great (i've had it for 3 years, but never had a chance to dive into it til now), it always seemed to stumble on itself if given gas too quickly, and has progressively idled worse, until it started to noticeably hunt in idle which is why i've started this process.
Anyway i live at 7k elevation, and came across some information about a high altitude plug on the bike. I've looked and looked and cannot find it. However I did find a plug that had been disconnected, and a plug with no connection to it. I'm trying to figure out what each of these plugs do(thinking one could be the high altitude plug)?! both have been unplugged since i bought it, so I'm interested in finding out how they affect the bike.
Here are two pictures of the plugs. The top three prong plug was unplugged when i found it.
The bottom two prong plug has not mate, and i'm assuming this is the high altitude plug?