BMW motorcycle trouble

Reece · 12-20-09, 06:11 AM

I have an old 1987 BMW K100 motorcycle, that runs rough!! actually not ridable!!

When I start and run up through the gears riding modestly all is ok, but once in top the bike holds it's own until I encounter a hill, naturally I have to apply more throttle but the bike does nothing, almost seems to die, if the hill is steep I may have to drop back a couple of gears, even on a straight if I try to accelerate the bike again refuses to respond, and if I open it out completely the power is really reduced and the revs drop and engine runs rough, can pull the clutch in and the engine revs are only around 1500 rpm, running very rough, if I slowly release the throttle the engine will recover and almost scream, if it had a carby I would suspect this but it is fuel injected, the fuel pump has been a little noisy even when tank is full lately, so I am wondering if this could be the problem or the filter, both are submerged at the bottom of the fuel tank and if I had to guess I'd say that it's probably original!!

Could the pump/filter cause this, if not any suggestions very welcome, trouble with bikes is getting access to parts, virtually have to strip it to do anything plus parts for a BMW are not cheap!

Thanks.

Edit: It is not likely to be plugs, leads, or injectors, since it's unlikely that all 4 would die at once.

12-20-09, 06:11 AM	#1
Reece CINC Pacific Fleet Join Date: Sep 2003 Location: Down Under Posts: 34,688 Downloads: 171 Uploads: 0	BMW motorcycle trouble I have an old 1987 BMW K100 motorcycle, that runs rough!! actually not ridable!! When I start and run up through the gears riding modestly all is ok, but once in top the bike holds it's own until I encounter a hill, naturally I have to apply more throttle but the bike does nothing, almost seems to die, if the hill is steep I may have to drop back a couple of gears, even on a straight if I try to accelerate the bike again refuses to respond, and if I open it out completely the power is really reduced and the revs drop and engine runs rough, can pull the clutch in and the engine revs are only around 1500 rpm, running very rough, if I slowly release the throttle the engine will recover and almost scream, if it had a carby I would suspect this but it is fuel injected, the fuel pump has been a little noisy even when tank is full lately, so I am wondering if this could be the problem or the filter, both are submerged at the bottom of the fuel tank and if I had to guess I'd say that it's probably original!! Could the pump/filter cause this, if not any suggestions very welcome, trouble with bikes is getting access to parts, virtually have to strip it to do anything plus parts for a BMW are not cheap! Thanks. *Edit:* It is not likely to be plugs, leads, or injectors, since it's unlikely that all 4 would die at once. __________________ *Sub captains go down with their ship!*