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My wife's 2003 R1150R is running rough, and idling poorly. I'll say upfront that the cables are seated in the ferrules, and both TB cams are seated against the stops.

AFAIK it was running ok prior to the 24k service, which makes me think it's something I did - I just can't figure out what. Most of what I did was changing fluids (eng oil/trans/FD/brake/clutch), spark plugs (gapped to .031), servicing K&N air filter. I also checked the valve clearances, but only the left side needed a SLIGHT adjustment.

When I restarted the bike it wanted to stall, did not idle well, and was rough when rev'd up. I assumed it needed a good TB synch, so I took it out for a ride to warm it up. When I got back it was idling but not well. It did synch at idle on the Twin Max, but with the right unscrewed 3 turns and the left nearly closed completely.

If I try to manually rev up the right cylinder the engine stumbles instead. The left side revs up just fine. I did not attempt the off idle adjustment - figured there was no point until this issue is sorted.

I have not touched anything with the fuel system, so it's not something I disturbed or screwed up there. I've checked that I have spark on both sides, and compression is the same on both cylinders. I'm not sure how to remove the fuel injectors yet, but plan to check that once I figure it out.

Any ideas????

Certainly sounds to me that the right cable sheath has pulled out of the metal ferrule on the righ-hand TB and that's why you had to make such HUGE changes to the adjusters. I know you said it wasn't displaced, but that is the MOST COMMON complaint (having those exact symptoms) after reinstalling the tank. Just sayin'!

Good luck.

Sunbeemer wrote:Certainly sounds to me that the right cable sheath has pulled out of the metal ferrule on the righ-hand TB and that's why you had to make such HUGE changes to the adjusters. I know you said it wasn't displaced, but that is the MOST COMMON complaint (having those exact symptoms) after reinstalling the tank. Just sayin'!

Good luck.

I know, I wish it was that simple... You don't know how many times I've looked at the cables, thinking why can't that be MY problem.

Try pulling the plugs back out and switching them then make sure the plug wires are firmly seated onto the plugs. See what that does.

Boxer wrote:Try pulling the plugs back out and switching them then make sure the plug wires are firmly seated onto the plugs. See what that does.

I did that, and no difference. I was going to see what else I can swap from left to right - like wires or injectors. I wish I could find the article Paul Glaves wrote in the ON that covered fuel injector testing, but it's eluding me at the moment.

Cygnus wrote:My wife's 2003 R1150R is running rough, and idling poorly. I'll say upfront that the cables are seated in the ferrules, and both TB cams are seated against the stops.

AFAIK it was running ok prior to the 24k service, which makes me think it's something I did - I just can't figure out what. Most of what I did was changing fluids (eng oil/trans/FD/brake/clutch), spark plugs (gapped to .031), servicing K&N air filter. I also checked the valve clearances, but only the left side needed a SLIGHT adjustment.

When I restarted the bike it wanted to stall, did not idle well, and was rough when rev'd up. I assumed it needed a good TB synch, so I took it out for a ride to warm it up. When I got back it was idling but not well. It did synch at idle on the Twin Max, but with the right unscrewed 3 turns and the left nearly closed completely.

If I try to manually rev up the right cylinder the engine stumbles instead. The left side revs up just fine. I did not attempt the off idle adjustment - figured there was no point until this issue is sorted.

I have not touched anything with the fuel system, so it's not something I disturbed or screwed up there. I've checked that I have spark on both sides, and compression is the same on both cylinders. I'm not sure how to remove the fuel injectors yet, but plan to check that once I figure it out.

Any ideas????

Update:
The spark plug on the side that isn't running correctly was darker colored, not sure if I would consider it sooty - but maybe a little (both new)
Swapping spark plugs from left to right had no effect, so not a bad spark plug
Spraying starting fluid over the TB and mating connections to the head produced no change, so no air leak
Switching plug wires had no effect, so not a bad wire
Switching injectors had no effect, so not an injector problem
I removed both idle speed screws, compared the thin layer of grime (same) and cleaned them

I can rev the bad cylinder a little bit just off of the stop plate before it stumbles, but not much. If it is running on fast idle I can almost coax it to 3k RPM's

You've got a single spark engine right? If not, I've heard of similar complaints on duel-spark models when a plug-mounted coil fails on the primary (or is it the secondary - I don't have them so I don't know which plug is called which) spark plugs.

Cygnus,

You can NOT open just the right side throttle pulley and have the engine speed up. The TPS black box on the left TB tells the Motronic to add more fuel when the left TB is opened, with the throttle or by rotating just the left TB's cable pulley. If you open only the right side TB throttle, you are asking that cylinder to make more power with just the miniscule idle mixture fuel volume (determined by the closed left TB throttle). It will not do that, it'll misfire, just like it did for you.

For OilHeads, the problem is likely 1 of these 4 things:
1--A dead stick coil
2--A fouled sparkplug
3--A TB synch error . . . possibly created by hand rotating the throttle shaft pulleys. Also, the cable could have pulled out of the throttle junction box (well hidden under the airbox).

4--An (unconscious?) error in the valve adjustment.


For #3, Repeatedly work the throttle on/off/on/off the idle stop (engine off) and listen to the left & right TB stop screw's tap sound. It should sound like 2 parts hitting at the same exact instant, NOT a quick/close sequence of 2 taps. That sound will tell you for sure that the sync is "off". Use a homemade water manometer to most accurately synch the TB's. You'll need 20 feet of 1/4" OD X .170" ID tubing, a 5 foot long board, with 90% water, 10% Alcohol and food coloring suction filled to just over 1/2 way:



For #4, Removing the sparkplugs prior to adjusting the valves can and will drop carbon dust from the loosening sparkplug threads onto an open valve below. On OilHead motors, at any crankshaft rotation position there is ALWAYS one of the bottom set of valves at least partially open on one cylinder or the other, proven by reading/calculating the cam timing specs. That very hard, dislodged sparkplug thread deposited dust sticks to the open valve face and/or valve seat sealing area. When you turn the motor for TDC, one, maybe two of the 4 bottom valves on the overlap stroke will close on that dust, holding it partially open. You then readjust that valve's larger clearance smaller to get it in spec. When the engine starts, the trapped carbon granules are blown away and the valve clearance gets much smaller/tighter, which can cause a power loss and unstable running. If you did find 1 or 2 of the lower valves loose, that means you do-over the valve adjustment. NEVER remove boxer motor sparkplugs prior to adjusting the valves, unless you like doing the job twice.

EDIT: To add text enhancements and change photo host from PhotoBucket to the faster, less intrusive Postimage.org

CycleRob wrote:Cygnus,

You can NOT open just the right side throttle pulley and have the engine speed up. The TPS black box on the left TB tells the Motronic to add more fuel when the left TB is opened, with the throttle or by rotating just the left TB's cable pulley. If you open only the right side TB throttle, you are asking that cylinder to make more power with just the miniscule idle mixture fuel volume (determined by the closed left TB throttle). It will not do that, it'll misfire, just like it did.

CycleRob,

Thanks for that information. I started thinking about the TPS only being on the left cylinder, and wondering if I was chasing a ghost. On carbeurated engines that isn't an issue, but I'm still fairly new to working on the Oilheads. I was trying to confirm my suspicion, which you did.

I put everything else back together last night and will re-check the valve clearances very carefully tonight, keeping your suggestions about the carbon in mind (I did pull the plugs when I did it the first time). Once that is complete I will check that the cables hit the stops at precisely the same moment, and attempt to do the synch.

P.S. - this is a single spark for those that were wondering

It sounds like a problem I had on my old airhead. A bad plug wire.

After doing a more careful and thorough valve adjustment, and putting all the swapped parts back in their original locations, I was able to correctly synch the TB's at idle. Once that was completed I did the off-idle cable adjustment and re-checked the idle. Now all is smooth again.