Author Topic: First BMW, Not sure where to start. (Read 14010 times)

Chubbs · « **on:** June 30, 2015, 01:42:33 PM »

Hey hey dudes,

I just picked up my first ever BMW and I am tickled silly on this thing! Its got some quirks that I feel pretty confidant to tackle, but it also has some that have me completely clueless. I have owned, rode, maintained and rebuilt old Hondas for years now. I have a pretty good general idea how stuff works but when it comes to all this fuel injection and BMW weirdness I am lost.

The previous owner said he rode it home and when it didnt start the next morning he simply rode another bike and let this one sit for 2 years before selling it to me. I threw in a new battery and some fuel and it fired right up. It has a super low idle and wants to die unless I roll on the throttle soft. Once past 1,500rpms it does great, Well enough to ride around town no problem. The video shows exactly what I am talking about. Using the choke helps bring the idle up but it still wants to bog/die if I dump the throttle.

Being fuel injected I am not sure where to really start. Do I clean the injectors? run seafoam and pray? What are my first steps to try to eliminate that bog?
There are also some noises that are concerning. It sounds a bit like one of the valves are too loose... or too tight? Shims are a new game for me. Also is that whining noise something I should be concerned about or is that a normal BMW sound? Any and all advice you guys can offer up would be greatly appreciated. I don't mind putting some time and moneys into this bike, I plan on keeping it for a long time to come.

Thanks in advance dudes,
-Chubbs

johnny · « **Reply #1 on:** June 30, 2015, 03:11:35 PM »

greetings chubbs...

welcome to motobrick.com...

id drain the fuel tank... replace the fuel filter... fill it up with no corn ethyl... run a whole 20oz bottle of techron through it... 10oz to 2@ back to back tanks of fuel...

id also pull the air filter for a look see... then i would replace all the fluids... forks brakes engine gear box radiator final drive...after lubing the splines id ride it and ride it and ride it... getts me some tiors and getts me some yeeehaaaaaa...

some are gonna say cracked rubber hoses at the air box and at the throttle bodies... and a couple in particular are gonna say tight valves... im gonna say it just needs to be ridden long and hard and figger that other stuff out later...

abouts that whining noise... wear ear plugs...

j o

motodude · « **Reply #2 on:** June 30, 2015, 03:48:12 PM »

Nice lookin' bike.

Johnny's comments are pretty spot-on. Replace the lubes, fluids and tyres. Ride it a bit.

I'm not sure what whining tou're hearing,but these things have been referred to as, K-whiners in the past. Usually the fuel pump is the source. If the whining is louder when low on fuel, it might be the FP.

Tom

RobP · « **Reply #3 on:** June 30, 2015, 04:45:48 PM »

Here's a good thread to read if you are a new K owner: http://www.motobrick.com/index.php/topic,370.0.html

My new-to-me K100RS is fresh out of long-term storage and unuse. As Johnny said, I went through and replaced all fluids, plugs, did a spline lube and fixed lots of 'smalls' that were broken or missing.

I probably hear a similar 'whine' as to what you may be experiencing.

rbm · « **Reply #4 on:** June 30, 2015, 04:59:20 PM »

Idle's not right. Check all the rubber bits like the throttle body rubber bushings that connect the TBs to the engine block, and especially the "Z" shaped hose that goes from the air plenum to the crankcase (on the left side right behind the fuel rail. See if it is cracked. If so, replace it. Also check the 90° elbow that connects the mass airflow sensor (MAS) to the air intake. Those clamps might be loose and letting in unmetered air. Check the state of the spark plugs to see if they are showing a lean mixture. That's another indication of air leakage going on.

Chubbs · « **Reply #5 on:** June 30, 2015, 08:48:39 PM »

Change fluids and ride, I think I can do that! :2thumbup:

RobP - Thanks a ton for that link man! I dont know how I missed it earlier but that was super helpful.

rbm - I think that is whats going on. Today while fiddling I noticed this vacuum line was way to loose and ready to fall off.

Quick peak at one of the spark plugs shows a little lean. I think hunting air leaks is going to be my biggest task.

F14CRAZY · « **Reply #6 on:** June 30, 2015, 09:24:33 PM »

That vacuum hose runs to the fuel pressure regulator. It may be a good idea to remove the fairing, airbox (from the right side, least on my K75) and replace that line. Also wouldn't be bad to replace the fuel lines while you're in there as access is easy and we've had bikes exploding here (ask for fuel injection line, not carb-ed line, from an auto parts store)

Elipten · « **Reply #7 on:** June 30, 2015, 09:48:08 PM »

All the rubber bits are old and stiff. Start replacing.

dfx · « **Reply #8 on:** July 12, 2015, 02:54:10 AM »

Still looking for help since my post on the thread 'Gas leaks at injectors?'. I read the exploding K75 story and this thread, so today I'm going hunting for leaking fuel lines, though all seemed good when I took it apart to do the o-rings.
I'm looking for the exploded diagram of the MAS and the 90° line but I don't see it on RealOEM.com, can anyone give me the part number?
Thanks

Tuco · « **Reply #9 on:** July 12, 2015, 06:53:37 AM »

Sounds normal to me, like a Singer sewing machine!

Inge K. · « **Reply #10 on:** July 12, 2015, 07:21:46 AM »

Quote from: dfx on July 12, 2015, 02:54:10 AM

I'm looking for the exploded diagram of the MAS and the 90° line but I don't see it on RealOEM.com, can anyone give me the part number?

13 31 1 460 563 (K75)
13 31 1 460 386 (K100)

dfx · « **Reply #11 on:** July 12, 2015, 09:51:12 AM »

Thanks for that, Inge.

I took the tank off and I wondered if something isn't wrong there. The manual says to disconnect the supply and return pipes and be ready for some fuel spillage with a cloth. Then I noticed that only after, it indicates to undo the bolt and start moving the tank. Does that mean that fuel should NOT continue to leak from the supply pipe? Cos mine does. Is it a problem? I had a lot of fuel in the tank, so I had to get it off as quickly as possible, and I placed it in a vertical position. Then I noticed fuel leaking from 1 of the small pipes to the rear of the centre towards the right. I think these are breather pipes but don't know how they work. Can anyone explain?

rbm · « **Reply #12 on:** July 12, 2015, 11:20:29 AM »

The two pipes exiting the tank to the rear are breather/drain pipes. One has a pickup near the gas cap that will serve two purposes -- allow air back into the tank to prevent a vacuum and safely direct fuel overflow. This pipe will collect fuel when the tank is full and temperatures cause the fuel mass to expand. This fuel overflow is normally dumped through a hose to the rear of the bike. Similarly, the second pipe is a water drain. Its pickup is on the gas cap left side. When rain water collects around the gas cap, this drain directs that water to the rear of the bike, rather than risk having that water dump into the gas when the cap is opened.

If you oriented the tank in a way that the gas started to hit the cap, it's likely the leak was directed through one of these pipes.

Tuco · « **Reply #13 on:** July 12, 2015, 12:34:17 PM »

Curious, when you open your fuel cap, do you see into the tank or is there this goofy stainless steel fuel door thing that only allows only the smaller unleaded fuel nozzle to fill the tank. My '85 didn't have one but my '87 did. Easy to remove, gives you a bit more fuel capacity and makes the tank easier to fill.

dfx · « **Reply #14 on:** July 12, 2015, 02:04:52 PM »

No I don't have one of those things inside the filler cap.
Thanks for the explication, the tank had a lot of fuel. But should it continue to pour out like that? Shouldn't the fuel pump stop it when not running?

Tuco · « **Reply #15 on:** July 12, 2015, 02:24:21 PM »

If you have the tank completely removed from the bike, the electrical plug to the fuel pump disconnected, then the fuel pump is not functioning. Its just your old friend gravity. Post some pics if you would so we can see whats going on.

Chubbs · « **Reply #16 on:** July 17, 2015, 11:08:56 AM »

Finally got back from my last adventure and have a little time to dig into this thing.
I swapped in some NGK D7EA and found the old ones looking like this.

I am about to pull the fairing and start checking around for what all rubber bits need replaced. Pretty clear afterwards I should get this thing all synced up too.

K75RT Keith · « **Reply #17 on:** July 17, 2015, 01:32:13 PM »

Looking at those plugs, you might think about either having the injectors serviced or replace the injectors.

Chubbs · « **Reply #18 on:** July 17, 2015, 03:03:33 PM »

Quote from: rbm on June 30, 2015, 04:59:20 PM

especially the "Z" shaped hose that goes from the air plenum to the crankcase

Yeah, thats for sure bad. haha

Also peaked under the little electronics box under the tank and noticed these guys just hanging out. Should the be plugged into anything?

Quote from: K75RT Keith on July 17, 2015, 01:32:13 PM

Looking at those plugs, you might think about either having the injectors serviced or replace the injectors.

Is that something I can service with time and effort or do I have to ship them in somewhere?

dfx · « **Reply #19 on:** July 17, 2015, 05:21:26 PM »

Quote from: Chubbs on July 17, 2015, 11:08:56 AM

Finally got back from my last adventure and have a little time to dig into this thing.
I swapped in some NGK D7EA and found the old ones looking like this.

my plugs look like one of yours, I can't remember which one though! :clap: Not the black one, I think

dfx · « **Reply #20 on:** July 17, 2015, 05:26:41 PM »

Quote from: Tuco on July 12, 2015, 02:24:21 PM

If you have the tank completely removed from the bike, the electrical plug to the fuel pump disconnected, then the fuel pump is not functioning. Its just your old friend gravity. Post some pics if you would so we can see whats going on.

But would the bike run without the pump? What do you want a picture of? I emptied what I could of the fuel from the pump outlet, and now the tank is sitting on it's side so that the rest doesn't leak out.

Glacial · « **Reply #21 on:** July 17, 2015, 06:41:51 PM »

Quote from: Chubbs on July 17, 2015, 03:03:33 PM

Also peaked under the little electronics box under the tank and noticed these guys just hanging out. Should the be plugged into anything?
[/quote]

Those are connectors for optional accessories,they are OK not connected to anything

Chubbs · « **Reply #22 on:** July 19, 2015, 12:02:33 PM »

Quote from: Glacial on July 17, 2015, 06:41:51 PM

Those are connectors for optional accessories,they are OK not connected to anything

Rad! Thanks man!

Next up...
These things! They are pretty blown and super stiff. Would it be alright to cut the center out and leave the outer ring for all the fairing bits? Or are they pretty needed for wind control? If I can buy them new I would be totally down with that. Servicing the forks is on my list of things to do anyway.

That questions leads into this one, Where do you guys buy parts? So far the only piece I NEED is that little rubber Z hose ("BMW 1 460 480 v15" on the hose) but knowing a good all around website would be amazing. Like I said before, Any and all information is super super appreciated. This website is such a help to a BMW noobie.

Tuco · « **Reply #23 on:** July 19, 2015, 12:15:16 PM »

My LT doesnt have them, neither did my RS. Should be OK to gut 'em.

billday · « **Reply #24 on:** July 19, 2015, 01:54:47 PM »

Chubbs,

Do you have a book? Haynes or Clymers will answer many of your questions, and while you're searching for your answer you'll pick up other useful knowledge.

Likewise, spend some time exploring this forum. Just about every issue known to man and K-bike has been explored here, and there are lots of excellent writeups. The forum is searchable and there's also a thread that's nothing but an index of every technical writeup. There's also a whole section all about parts sources.

Enjoy your new K bike and thanks for being part of the Motobrick family!

Cheers,

Bill

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Author Topic: First BMW, Not sure where to start. (Read 14010 times)