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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: k projekt on August 08, 2019, 06:33:01 AM

Title: Bike Powers down after a long ride?
Post by: k projekt on August 08, 2019, 06:33:01 AM
Howdy all!

I've got a 1985 K100RS, my dad has had this bike for many years and it sat in the garage for a few years until i decided to take it to a shop to get it up and running again.

The shop did a great job and got the engine up and running again.

Problem is, after a long ride the bike seems to stop pumping fuel to the rail and will shut off, it feels like its out of gas when it has a full tank.
Once this happens its flashers on and moving to the side of the rode. I'll put my ear up to the engine when i hit the ignition to try and hear the fuel pump kick on and there's nothing, so its a wrecker and another 120$ to get home.

The strange thing is that you only get this problem once you go on a long ride, are we overheating possibly? IDK, any guidance from the community would be helpful, thanks guys!
Title: Re: Bike Powers down after a long ride?
Post by: Scott_ on August 08, 2019, 06:42:37 AM
As Johnny would say, check the four pin tank connector..... clean and re-seat. This is for starters....
What did the shop do to the bike to get it running..... should be listed on the repair bill.
It's possible it could be the fuel pump, but we aren't there yet in the diagnosis.
Title: Re: Bike Powers down after a long ride?
Post by: johnny on August 08, 2019, 07:47:47 AM
gretings...

poast up some photos of this k projekt... we dont know what you have there... we need to see it... could be the bep3...

j o
Title: Re: Bike Powers down after a long ride?
Post by: Chaos on August 08, 2019, 08:21:24 AM
Sounds like classic Hall Effect Sensor failure.  Especially if it runs again after it cools down. 
Title: Re: Bike Powers down after a long ride?
Post by: The Mighty Gryphon on August 08, 2019, 09:01:09 AM
I'm going with the Hall Effect Sensors too.  Haven't had a bike with that problem around here for a while now.  I figure we're due, and your bike is the one. 

A quick test would be to put the bike up on the center stand, take the sensor cover on the front of the engine off and hit the sensors with a hot air gun while it's idling.  If that stops the engine let it cool, and see if it starts again.
Title: Re: Bike Powers down after a long ride?
Post by: johnny on August 08, 2019, 09:22:47 AM
greetings...

if you are gonna be breaking down on a moto you oughtta getts aaa rv premier... (https://wisconsin.aaa.com/membership/pluspremierrv.aspx?zip=53039)

poast up photos of your moto... did you run the vin to make sure itsa 85... pre 86 are different than 86 and later... depends on build date... not what your title says...

we aints had a whack fore pin around here for a decade or longer... we discussed this in detail on our secret board... the cappuccino craftsmen and dumpsters board...

we are due... its you... you fore pin is whack...

yous is on left side under tank being a 85 and all...  (http://www.motobrick.com/index.php/topic,11033.0.html)

j o
Title: Re: Bike Powers down after a long ride?
Post by: Laitch on August 08, 2019, 02:34:21 PM
Sounds like classic Hall Effect Sensor failure.
I'm going with the Hall Effect Sensors too.  . . . A quick test would be to put the bike up on the center stand, take the sensor cover on the front of the engine off and hit the sensors with a hot air gun while it's idling.  If that stops the engine let it cool, and see if it starts again.
He wrote dumpsters board . . .  :welcome

+1 on Hall sensor defect and test.
Title: Re: Bike Powers down after a long ride?
Post by: Laitch on August 08, 2019, 03:05:58 PM
Hall Effect sensor cover.
(http://www.motobrick.com/gallery/2/1601-080819150440.png)
Title: Re: Bike Powers down after a long ride?
Post by: billday on August 08, 2019, 06:13:27 PM
hit the sensors with a hot air gun while it's idling.  If that stops the engine let it cool, and see if it starts again.

Works best if you use your wife's blow dryer.
Title: Re: Bike Powers down after a long ride?
Post by: k projekt on August 08, 2019, 10:23:23 PM
greetings...

if you are gonna be breaking down on a moto you oughtta getts aaa rv premier... (https://wisconsin.aaa.com/membership/pluspremierrv.aspx?zip=53039)

poast up photos of your moto... did you run the vin to make sure itsa 85... pre 86 are different than 86 and later... depends on build date... not what your title says...

we aints had a whack fore pin around here for a decade or longer... we discussed this in detail on our secret board... the cappuccino craftsmen and dumpsters board...

we are due... its you... you fore pin is whack...

yous is on left side under tank being a 85 and all...  (http://www.motobrick.com/index.php/topic,11033.0.html)

j o

I've taken a wire brush to the 4 pin and gave it a good crc bathing, letting it idle and wiggling the connection around proves unfruitful.

The tow truck driver ran the vin, genuine 85. Sad when you know your tow truck driver by name. For the break downs, my dad suggested we rent a trailer from uhaul he can follow me in the car with.

Hall Effect sensor cover.
(http://www.motobrick.com/gallery/2/1601-080819150440.png)

This is an interesting lead, I'll look into it and keep you guys posted.

Also, new fuel pump/fuel filter came today and was installed, ran around the block just fine.
Title: Re: Bike Powers down after a long ride?
Post by: k projekt on August 20, 2019, 09:34:06 AM
Quick update: Replaced the fuel pump and filter and went for a nice ride during the weekend, probably ~50miles or so with no problems, then last night I set out for a ~15 mile ride and the pump quit on me.

Tried to start it back up and could hear the fuel pump running but the bike wouldn’t turn over. I’m going to look into the 4-pin connector to the gas pump just to check that box and try to figure this mess out.
Title: Re: Bike Powers down after a long ride?
Post by: natalena on August 20, 2019, 01:38:49 PM
Sounds crazy, but I'm betting that headlamp has something to do with it .. it just looks, well, shifty and beady eyed.