Monday, March 23, 2009

Biting the Bullet

As much as I am loathed to part with either of my motorcycles so that they get some issue fixed by a real mechanic; I had to drop Maria, my 2004 R1150RT, off at Pete Homan's Bavarian Motorcycles West during lunch today.

I had ridden Maria because the temperatures were not expected to get above the low 50s and she provides so much better wind protection than Brigitta, my 1987 R80 Beemer.

On the way to work, the slight surging behavior that had been exhibited prior to my TBS sync being done at 65,500 miles remained evident. Its a rather annoying feeling, a slight surging forward as I held the throttle steady....usually in 2nd or 3rd gear, around the 3500 rpm range.

I am pretty sure I didn't dork up the TBS Sync and remain at a loss as to what would cause this. Perhaps a fuel filter issue (which requires the removal of the tupperware, gas tank and fuel filter assembly from WITHIN the gas tank. Maybe the Hall Effect sensor is malfunctioning which could get expensive. Perhaps the fuel injectors are clogged but since I'd recently changed her oil, didn't want to try fuel injector cleaning fluid on at least one full tank of gas since you're supposed to change out the oil soon after using that stuff.

Rather than guessing at all the above, and to get a mounting hole fixed on the right side valve cover, I turned Maria over to Pete. Now to await his diagnosis. Luckily, I still have Brigitta to satisfy my riding habit.

24MAR09 Updated: Picked up Maria from Pete's place today. He found grit on the pulley where the throttle cables travel, which probably was the major cause of the surging. He also found that I was setting the valve clearances as too loose! He repaired the stripped mounting hole for the right side valve cover bolt, and went ahead and did some preventive tapping of the other three holes which were apparently partially stripped.

Maria rides pretty smooth now, no surging which is good. I must now revisit the valve clearances on Brigitta since I used the same "slight drag" criteria on her valves, which means they are probably too loose as well. Damn. It's such a subjective thing, this "slight drag" business.

Pete mentioned also he likes to tighten the intake valves closer than the .015mm stated in the manual since they run cooler. Definitely go with the spec of .030mm on the exhaust valves though since they run hotter. Most definitely measure both valves at same time. I.E., run the feeler gauge on both exhaust valves simultaneously, same for the intake valves.

He mentioned also he found the right rocker arm, forward one, loose....probably from last june's crash he thought. So my valve clearance checks weren't right to start with due to my overlooking that check. I've so much to learn still.

Another thing is he doesn't go over 4 ft/lb on the valve cover screws. I thought the state spec of 8nm was too little, he goes even further. I'll go with his experience level of course the next time the covers are off for valve checks. You also can cross-thread these screws real easy, must take it very easy when putting them in!

Finally he must have adjusted the play on the throttle, there's not much play at all now.


Jack Riepe said...

Dear Charlie6 (Dom):

Man! The Hall Sensor... There's a phrase that strikes fear into a BMW rider's heart. Here's a stupid question for you, "Do "K" bikes have Hall sensors?

I thoughrt I had read someplace that the surging problem can be fixed with a "chip?" Is this true? Or did I misunderstand the whole surging issue?

For me, there would be no issue of even trying t repair my own bike. The rig would have to go into the shop. I have a great guy who comes to the house for a lot of stuff, but once every couple of years I feel compelled to send the bike to a master.

Here's hoping you trip to the shop is nothig more than dirt on a connection.

I haven't been on it since it last came back. I can hardly wait. I have something opf yours awaiting return. I'll get it back to you tonight.

Fondest regards,
Twisted Roads

Charlie6 said...

Hi Jack

I would think your bike does have a Hall Sensor but I don't know K Bikes. Since its an ignition timing device, I bet you do have it.

Surging was an issue with the 1100 series single spark plug bikes, which required careful valve checks and throttle body syncs and still there was some surging. That's why, though BMW won't admit it I've read, the 1150 series are dual spark plug equipped.

In my case, it was a right side rocker arm which was apparently loose and I missed it during the recent valve check. The mechanic corrected that, found grit in the pulley used by the throttle cable which was causing the surging and tightened up my valves which were too loose. In other words, I've still much to learn about working on motorcycles. I also apparently set Maria's valve clearance too lose.

She's all fixed now, I pick her this afternoon.