Hello

I just bought this bike. Rode home over 80 miles, no issues. Went to ride one day, noticed fuel spraying heavily. The line going from fuel rail to the fuel pressure regulator had a crack, thusly spraying. OK, cool no big deal.

I bought generic fuel line from the parts store down the street, cut to the same length as OEM ( I did not want to pay the 20+ per line from BMW). I reinstall everything in reverse order per usual. Go to start the bike, and it acts sluggish. Almost wants to start, but doesnt. Got it to turnover and idle for a COUPLE of seconds, but a blip of the throttle kills it. I confirmed no leaks in the lines, very weird. The more I try and start the bike, the less it wants to ATTEMPT to run. Finally it just backfires really loud and battery dies.

I bring battery charger out, try start6ing again. Nothing. Backfires now and again very loudly like a single gun shot. Keep in mind, before this it would start IMMEDIATELY on first touch of the Starter button. Tried starting with the choke on, no luck.The bike stays outside in TN weather which has been very mild. Was told by PO that its a bit harder to start when its cold out, but still, what the hell. I had to take the airbox out of the bike, maybe I buggered the connection to the MAF? Any of these things sound familiar to you guys?

Pics of the bike just because: :pirat:

Thanks in advance!

Check the fuel pressure regulator behind the throttle bodies may have jammed or seized being the reason that your return line failed in the first place .
Is fuel returning to the tank when you try to run?
Quick check is to bypass the regulator and kink the hose ( enough to allow fuel to return to the tank ) then see if she starts

Thats a great recommendation, thanks Toto_jp.

Ill check that out this weekend. Is it possible for me to just bypass the regulator forever?

NO it needs the pressure and damn expensive for OEM there is a thread from few days back that lists aftermarket makes and at a cheaper price

I would go along with the other suggestions so far - the problem is almost certainly Fuel Pressure Regulator related - ask me how I know.... Or see following link:
http://k100rt.aforumfree.com/t2007-k100-rt-engine-bogs-when-you-wrench-the-throttle

Actually your post has stirred my grey matter to the point where I now realise that all my problems first started just after I had fuel line issues and after replacing just about every other fuel related component on my journey to discovering the real problem. Hopefully this might save you from all the heartaches that I had along this road to revelation until the members of this forum finally pointed me in the right direction

One other problem with fuel lines is the in-tank lines are different from the outside the tank lines. If you use fuel line intended for outside the tank use inside the tank it will break down and probably burst/split. The rubber on in-tank lines is the same on the outside of the hose as it is on the inside. With outside the tank hose the two types of rubber are different, annoyingly they look the same but the rubber on the outside breaks down when immersed in petrol.
Regards,
K-BIKE

Ok gents, I pulled the airbox to get a good look at the FPR again. Confirmed no weird bends or kinks, smooth good looking routing.
Did not disconnect the lines to the FPR as its sitting in the street at the moment and I dont have proper tools at my house at the moment.

Also found a cracked and dirty hose. Its in pretty bad shape. Could this be whats causing the no start?

K-BIKE wrote:One other problem with fuel lines is the in-tank lines are different from the outside the tank lines. If you use fuel line intended for outside the tank use inside the tank it will break down and probably burst/split. The rubber on in-tank lines is the same on the outside of the hose as it is on the inside. With outside the tank hose the two types of rubber are different, annoyingly they look the same but the rubber on the outside breaks down when immersed in petrol.
Regards,
K-BIKE

I bought fuel line for outside and used it outside. Ive used this same stuff on my car. I guess BMW motorrad sells individual hose pieces, but BMW auto does not. They just sell in bulk, so I've used this stuff on my BMW cars before and its been great.

By the way, I tried to start the bike once I put everything back together and first 2 seconds of hitting the start button it almost acted like it wanted to start up. Then backfired and thats when I stopped.

That hose looks like it could be a source of an air-leak which would seriously compromise starting, I would replace it.
Regards,
K-BIKE

What source do you guys usually go with for OEM parts?

Ill go ahead and order it. Easy to try.

You can order from www.motobins.co.uk but not www.motorworks.co.uk , but here are heaps of sources in The States for Beemer spares, new and used. try Beemer Boneyard, K Bike parts Seattle, and even some dealers who don't mark up the prices beyond what's reasonable. I'm sure there are favourite dealers and sources other North Americans can twig you to. Either way, it's a helluva lot cheaper for you over there, where the market is bigger by a long country mile, as compared to here, where the market is one tenth of yours, but no less enthusiastic.

yes were all in agreement ....that breather tube ...crankcase to plenum is probably the issue .

yep total agreement ... breather tube ..... just don't drop the clamps putting the new one on.... being stainless they are not magnetic so you need extreme patience ... don't ask but took me 45 minutes to retrieve it

Toto_jp wrote:yep total agreement ... breather tube ..... just don't drop the clamps putting the new one on.... being stainless they are not magnetic so you need extreme patience ... don't ask but took me 45 minutes to retrieve it

Tinkle tinkle little part,
how i wonder where thou art?
i heard you as you hit the ground,
i saw you as you rolled around ,
tinkle tinkle little part .

i wish i had a dollar for every time i watched something fall out my fingertips, watched it hit and roll even thinking i know its final resting place only to find it had a higher need in a parralell universe , never to be seen again
*shakes fist at floor and then the multiverse*
*shakes fist at small brass guide inside horn button*
ahh the joy of it all

sorry, forgot to add . start with that engine breather hose , we will see how she rresponds thereafter eh ?
beer o clock !
N

aye bean ....that it is !!!

i agree just replaced mine , small split behind top clamp, rough idle, now smooth as silk.



regards Bushy

I needed to replace the one on the K75 and could not get it in time so I used some heat shrink to fix it and it is still there and working.

I will replace it when I next have it apart.

Heat shrink is wonderful stuff, I keep a few small lengths (100mm or so) of different diameters under the seat, you never know if and when it may come in handy, insulationg a scuffed wire, leaking hose etc.

Use the double cored stuff it has a built in glue that seals as it shrinks, and its finnished wall thickness is a bit ththicker too.

Bushy

Any news on this one, did it cure the bad starting? I have something similar at the moment, turns over OK, fires a few times and dies. Fuel pump is good, pressure is good, injectors working good.