Hesitation/Stall at 3-4k Rpms

[bergj1986]

About two months ago, I noticed my 03 1150R w/ 29k miles hesitates and almost stalls while riding on the highway in 6th gear at anywhere from 3-4k rpms. The rpms will start dropping and the engine loses power. If I apply more throttle, the engine springs back into life and revs normally.

Today when riding the bike in the city, I noticed the hesitation, quickly pulled in the clutch, and noticed the engine felt like it was running on one cylinder and quit. Once I reached the traffic light, she started back up and ran without issues.

I've already performed the following maintenance items:

- Throttle body sync
- Replaced spark plugs
- Installed metal QD's from Beemer Boneyard
- New fuel injection-rated tubing
- Replaced fuel filter (switched to external, issue was happening w/ internal filter)
- Fresh 93 octane gas

The bike will have this issue randomly, sometimes when the engine is at operating temperatures, sometimes when it's cold. I'm thinking the issue is in the Hall sensor, but from what I've read that tends to get worse as the bike heats up. I'm also thinking the spark plug caps could be shorting against the cylinder heads.

I ask you BMW guru's, what do you think the issue is? I love my bike but hate the hesitation!

[Ol' Jeffers]

I'm certainly no guru! But it sounds as if you have an intermittent electrical
connection or low battery voltage. Not much help I know as it could be anything
from a battery problem to any poor connection/ground in the ignition circuit. On the twin spark version
of the R1150R the ignition lead components are also known to fail.
Also you said you have a tank full of 93octane. My handbook specifies minimum
95 octane (RON). HTH

[Beemeridian]

16

[bergj1986]

I have not tried to crank the engine with the coils off the plugs, would I check this to see if the spark plug caps are shorting to the inside of the cylinder head? What is your reasoning for this test?

What is the proper ohm's reading for the ignition coils? My bike has a single spark plug per cylinder.

[Beemeridian]

14

[towerworker]

You have a single spark. You do not have stick coils--only conventional plug wires. (Better than dual spark!!) The single coil is located under the tank. 2004 was the start of the dual spark (at least in the US)
Both plugs fire simultaneously.

You won't damage anything by pulling plug and laying it up against the jug and cranking engine. Watch where you have your fingers!
A shorting plug wire might be visible upon close inspection at night with engine running (remove cover). Personally I think you may have some water in the tank

[Beemeridian]

13

[bergj1986]

I'll try that test and report back with findings.

At first, I thought the problem was water in the fuel, but the issue happens more often than not. I can put some fuel dryer in the tank and see if that makes a difference. Tried Seafoam in the last full tank, didn't make a difference.