A List of Random Questions (94 K1100rs)

[cheetah]

So one year of riding and 10,000 miles has prompted a few questions:

First:  Is there a known gear swap for 5th gear?  To my knowledge, 5th gear is 1.61:1  :musicboohoo:  Even 1:1 would be great; 1:1.61 would be  :beer:  I rode to work today and in 5th gear; ~15mph at idle, ~55mph at 3500rpm's?!!?  This engine has good low-end torque...why not use it?

Second:  In the heat (here in San Antonio) the temp gage is slightly right of the center mark riding at 70-80 mph in ~85°F+ weather.  Removing the thermostat goes too far the other way.  Has anyone ran a drilled t-stat with good results?  New coolant and new hoses last year.  Yes, distilled water and BMW official coolant & yes, 60/40 mix.

Third:  Good pair of led fog lights?

Fourth:  Do 94's have a MAF?

More as I think of them.  Thanks!

[Scott_]

Well, I'll tell you from personal experience the K engine LOVES to run high revs. I burnt 2 valves from "babying" one too much and not revving it enough. A taller 5th gear could potentially put you in that area.
I was running down the interstate today at 4500-5000rpm, and it sang like a top. These bikes are not like a V-twin.

Have you installed a manual fan switch? This can help the bike run cooler in city traffic.

Check some of the product review threads for fog lights.

I don't think any of the 1100's have the MAF sensor. It was used with the "jetronic" fuel system on the older bikes.

[cheetah]

Scott, thanks for the advice.  I'll do that right now.

And your right, they do sing at 4k rpm's +.  I rode from Kerrville to San Antonio (Interstate 10) for 50ish miles, doing 80-83 and the engine was spinning at 5100-5300 rpm's.  So smooth  :riding:  And the acceleration is phenomenal when you crack the throttle at that speed  :yes

[Grim]

After getting stuck in Atlanta rush hour traffic in full gear today and baked by the heat these things make I understand what your trying to do but here is some info to ponder

Fuel injected motors in general are intentionally run a little hotter thermostat than is traditionally excepted for carberated motors. This is to help reduce emissions. Factory the fans are set to come on at 211f and the idiot light comes on at 217. If you are getting fans and not getting light it's operating as intended.

Running them cooler then factory runs the very real risk of the ECM not going into closed loop thinking it has not achieved full operating temp. This could cause it to run rich and eventually clog the catalytic converter. 

They are amazingly forgiving at low RPM ant they? 

Swapping 5th would be nice I agree. I'm not aware of a new gear set for the transmission. The next gens k1200's got 6 speed boxes I believe with 6th being more of a hwy gear.  Wonder if it will bolt up?

What you might also investigate is swapping the final drive. I believe I read the LT had more of a hwy gear then the RS.
This is what my dad did back in the 60's with his R69s. He had a city final drive and a hwy final drive.

[wmax351]

I actually put a slightly hotter (by 2 *C) T-stat in my bike. 190* F, instead of 85*C. Though my bike is running Megasquirt, so the fueling is being compensated for.

[Lawrence]

As long as we're throwing questions out: How would running these engines in a taller gear than may be appropriate contribute to burned valves?

[Grim]

As long as we're throwing questions out: How would running these engines in a taller gear than may be appropriate contribute to burned valves?

Kind of curious about that myself.

The one time I have burned vales on anything was a Supra that had a injector running lean. It took me running about 90mph for 10 miles to do it.

Lower RPM gives the valve more time to dissipate heat to the head when closed. Seems to me it would be less chance of burning them.

[Scott_]

As long as we're throwing questions out: How would running these engines in a taller gear than may be appropriate contribute to burned valves?

In my case there was too much carbon buildup on the valves, wasn't getting burned out.

Was the lower rpm's the sole cause, probably not. But it was most likely a major contributing factor.

[cheetah]

I have no problem getting the carbon out  :2thumbup:   But the additional gas mileage would be nice - especially on a long road trip like the one I want to take in August.  I'm thinking with passing, merging and just for fun, carbon would not be an issue.

In my head, if the inside splines are the same for the two gears that make 5th, could they be swapped?  It would be a true overdrive then.

CSG makes a good calculator http://www.csgnetwork.com/rpmcalc.html

70 mph, 25.56 tire diameter, 2.81:1 differential, 1.61:1 transmission gear=4163 rpm's

With the same above only changing the transmission gearing to 1:1=2585 rpm's  :yow

Who can say 55+ mpg's :idea2: