Awakening 1987 K100RS from 10 year slumber.

[SpecialK]

Thanks guys for the spline info. Seems that's one of the most common issues to look after on these bikes. Will definitely check the slines when the time comes.

[The Mighty Gryphon]

I do mine as part of the end of season maintenance ritual.  I don't pay any attention to miles although I do record the odometer reading, and last year started taking photos of the splines to document their condition as part of the maintenance record.  My bikes annually get about 4-5,000 miles on the RS, and about 7-8,000 on the RT. 

The RT now has a bit over 92,000 milles and the splines are just beginning to show a hint of wear.  I would expect them to get me to at least 150,000 miles before I'll need a new driveshaft or final drive. 

[SpecialK]

They look to be in decent condition. Am curious to see what mine look like when I get in there. Have no idea if the bike was driven hard on rough roads or pampered. I'm hoping for the latter :2thumbup:

[natalena]

The fun thing about checking splines, is it's like opening a Kinder Egg. Sometimes it's a so-so toy, and sometimes it's awesome and worth dancing around the brick like a savage.

[SpecialK]

Not much work today except took the temperature sensor out of the water pump and drained the rest of the fluid. I saw a guy on youtube pull the wire clip off and use a 14mm socket so that's what I did. See photo.


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Here is another photo of a rubber, looks like crancase vent tube, in front of the air filter housing, that has a hex scew in it. Is the tube supposed to be open? Why would the hex screw be in there?
Thanks.

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[natalena]

That hex looks like it's plugging the tank vent tube that leads to the crankcase. Nearly everyone has that tube crimped, plugged or removed and the case hole plugged. No worries. The origin of the tube is the two nipples on the bottom of the gas tank.

[SpecialK]

The origin of the tube is the two nipples on the bottom of the gas tank.

Yes I saw those nipples. don't they just rest inside that little plastic cup under the tank?

[The Mighty Gryphon]

When you put the temperature sender back into the water pump be careful to only get it a bit more than snug.  The sender has a thin wall at the top of the threads, and if you get carried away with torque it will break off.

[Laitch]

Here is another photo of a rubber, looks like crancase vent tube, in front of the air filter housing, that has a hex scew in it. Is the tube supposed to be open? Why would the hex screw be in there?

Once upon a time, that vent tube was also attached to one of the two ports that now empty into the cup attached to the frame. There was a one-way valve in the middle of it. The tube's purpose was to meet California emission standards by venting fumes from the tank into the crankcase. It was an imperfect idea so the remedy was to remove the hose from the fuel tank then either plug the crankcase port or plug the hose, as natalena indicated. Somebody screwed your hose to plug it.  If the crankcase port were not plugged, the engine would likely run rough or stall.

After decoupling that from the crankcase, the tank vent port—and the fuel cap water drain port next to it—either had hoses attached to them that dumped behind the right foot peg plate, or the ports dumped into a cup attached to the frame like yours do. The cup should have a hose attached to the underside of it that dumps downward behind the right foot peg plate.

[SpecialK]

When you put the temperature sender back into the water pump be careful to only get it a bit more than snug.

Thanks. Yes I saw that in the Haines manual torque to 9.

[SpecialK]

Received fuel parts and battery from EME today. Not bad, ordered Friday and received today Tuesday, from Colorado to New York, Fedex. Anyway, here are the pics of the goodies.

Enduralast 52mm fuel pump kit (pump, housing, anti-vibration, fuel lines, fuel filter, filter cup, screws and clamps).

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WestCo 12V30 AGM battery.

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BMW OEM fuel level sensor.

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Will work on getting these installed over 4th Holiday. I am curious to see how the electrics come on after hooking up the battery.

Question; What is the best way to try an initial start-up since there may be old fuel in the lines and injectors? Should I take the injector rail out and crank the starter to expel old fuel out the injectors and into a container, or leave everything as is and try to start?
I will have to also refill the radiator with antifreeze since I drained it. I am figuring I can change the oil and filter after I get it started.

Thanks.

[SpecialK]

Regarding antifreeze coolant, radiator flush, oil and filter;
Are there common brands suitable for the K bikes available at the auto parts stores? I heard some people say they use any old antifreeze 50/50 like Prestone but I thought it should be specifically for alluminum block engines?

Thanks.

[Laitch]

I heard some people say . . .

I knew a guy who smoked two packs of cigarettes a day and lived to be 80. I quit smoking anyway. :giggles

Any extended life (long-life) coolant without nitrites is acceptable to BMW, according to the coolant specs within its rider's handbook for the K75, so read the label.

[natalena]

Regarding antifreeze coolant, radiator flush, oil and filter;
Are there common brands suitable for the K bikes available at the auto parts stores?

I only use BMW branded oil filters due to superstitious beliefs that the engineers knew what they were doing, as well as, the finance department at extracting your funds.
Since there's jugs of Mobil 1 Synth. in the garage, that's what I use. No gasket leaks, seal issues, or capricious running noted so far, as opposed to dino-oil.

[The Mighty Gryphon]

I get my oil filters from Carquest/Advanced who has WIX make them.  They are rated highly in tests of filter performance.  The part number is 85348. 

After reading a number of technical articles on oil, I have decided to get the oil with the highest possible film strength in psi.  The best readily available is Quaker State Ultimate Durability Full Synthetic 5w-30 which has a film strength better than 85% of the oils for sale today.   The best part is that Walmart sells it for $17.77 for a 5 quart jug.

For coolant, I am using Peak Long Life mixed 60/40 with distilled water.  It is stated to be safe for all engines and won't void new car warranties.  Nearly every new engine today has an aluminum block, and antifreeze manufacturers have had to adjust their formulas to accommodate the new engine requirements.   

[SpecialK]

I get my oil filters from Carquest/Advanced who has WIX make them.  They are rated highly in tests of filter performance.  The part number is 85348. 

After reading a number of technical articles on oil, I have decided to get the oil with the highest possible film strength in psi.  The best readily available is Quaker State Ultimate Durability Full Synthetic 5w-30 which has a film strength better than 85% of the oils for sale today.   The best part is that Walmart sells it for $17.77 for a 5 quart jug.

For coolant, I am using Peak Long Life mixed 60/40 with distilled water.  It is stated to be safe for all engines and won't void new car warranties.  Nearly every new engine today has an aluminum block, and antifreeze manufacturers have had to adjust their formulas to accommodate the new engine requirements.

That is really good information Gryphon! I was looking at the coolant in Advanced last night. Prestone has Long Life Dex Cool for aluminum radiators in full strength for $18.99 so that may be good as like you say, most of the formulas are designed for newer aluminum block engines.

Have you ever used a flush product for the radiator? I want to do that before I add any new coolant.

[natalena]

Have you ever used a flush product for the radiator? I want to do that before I add any new coolant.

Prestone antifreeze works well, and I religiously use distilled water after a bad episode with a 320i radiator.
Flushing with white vinegar works well. A gallon is cheap, when mixed with water and run to warm the motor, leave it overnight, drain, flush out with the hose, and fill with whatever antifreeze/strength you like.
Sounds like you're having fun with the process, and bonding with your brick. :)

[The Mighty Gryphon]

Natalena is right about the white vinegar.  If it isn't too much hassle right now, it might be a good time to pull the radiator and clean the accumulation of dirt and dead bugs that is in the fins, blocking the airflow. 

I did it with my first K100 and it really cooled off the engine on hot days.  It's something I'm going to have to do on the one I have now as the temperature gauge is reading a lot higher on hot days lately.

[SpecialK]

Flushing with white vinegar works well. A gallon is cheap, when mixed with water and run to warm the motor, leave it overnight, drain, flush out with the hose, and fill with whatever antifreeze/strength you like.

Sounds like you're having fun with the process, and bonding with your brick. :)

I am so glad you guys said the vinegar is good. I was thinking that since it worked so well cleaning the aluminum gas tank, why not the radiator. Now I don't have to go hunting down another $$ product.....and yes I am having fun, so far, as long as the process keeps going smoothly.... :yikes:

[SpecialK]

If it isn't too much hassle right now, it might be a good time to pull the radiator and clean the accumulation of dirt and dead bugs that is in the fins, blocking the airflow. 

I did it with my first K100 and it really cooled off the engine on hot days.

Good idea, thanks for that advice. Doesn't seem too difficult and would benefit in the long run.

[SpecialK]

Today I took the plugs out to check. They look oily, like the engine was running rich or maybe just from sitting or the PO shot some oil in the holes before storage?
I checked the gap and I couldn't get the plug to slide over the slimest point on the gap tool, .5mm. Specs say they should be 0.6 - 0.7mm. Is this narrow gap OK or open them to 0.6 - 0.7?
I tried turning the rear wheel (by hand) with bike on the center stand in first gear but could not (with the plugs out so no compression). The pistons move though once I roll it and let the clutch out. Is it usually too hard to turn by hand?

Also, in the relay box under the tank, there is a white and a black pin connector that are not connected to anything (see photo). Where do these go? Accessories?

Here are some photos:


Plugs and cylinder head

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Open pin connectors

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[Laitch]

Specs say they should be 0.6 - 0.7mm. Is this narrow gap OK or open them to 0.6 - 0.7?

Always go with the specs unless you're operating with cosmic dispensation for negligence. A gap that's too narrow will not fire hot enough. New plugs should be checked for correct gaps.

[SpecialK]

 A gap that's too narrow will not fire hot enough. New plugs should be checked for correct gaps.

Maybe that explains the oily appearance? They weren't firing hot enough. I will use the gap tool to spread them to 0.7mm.
Any idea about the blank plugs in the relay box?
Thanks Laitch.

[Laitch]

I tried turning the rear wheel (by hand) with bike on the center stand in first gear but could not (with the plugs out so no compression). The pistons move though once I roll it and let the clutch out. Is it usually too hard to turn by hand?

Which rotation direction were you tuning it, why didn't you try turning the wheel while the transmission was in a higher gear, and what was your objective? Debris from the cylinder head could have gotten sucked into the cylinder bores if you weren't a Tidy Timmy before your experiment.

Also, in the relay box under the tank, there is a white and a black pin connector that are not connected to anything (see photo). Where do these go? Accessories?

They don't go anywhere. They're happy where they are. The largeer is an accessory plug that has both switched and unswitched power; the smaller can also be use for appropriate accessories or an alarm.

[SpecialK]

Which rotation direction were you tuning it, why didn't you try turning the wheel while the transmission was in a higher gear, and what was your objective? Debris from the cylinder head could have gotten sucked into the cylinder bores if you weren't a Tidy Timmy before your experiment.

I was turning forward. I didn't think to move to a higher gear, thought first would be easiest The objective was to make sure pistons were not froze up.