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1Back to top Go down   K100 won't start after winter sleep Empty K100 won't start after winter sleep Thu Mar 25, 2021 6:34 pm

Tarlin

Tarlin
active member
active member
Hi,

after the bike spent the winter hibernation in the garage, it won't start. The problem started last year, same, after winter, but eventually as the weather warmed up it fired up, and ran without any issues for the whole season.

This year it is happening again. About a month ago, I was able to start the bike, connected to the car battery, but only after prolonged starting.

-The bike now has a new battery with a 400A start current, so the battery is definitely not the issue here, the starter motor also turns the engine without any hesitation.

-I put in a set of new spark plugs, just in case. Even tried the Criss Harris youtube procedure with adding 10ml of oil in each cylinder to improve compression, but to no avail.

-all 4 spark plugs tested for spark, looks ok. Spark plugs look moist with gasoline, smell of gasoline, so I guess the injectors are ok? Also the fuel pump seems ok, you can hear it.

-when I try to start the bike with the choke on, it just cranks, but shows no lust for life:)

-when I try to start the bike without choke, after a few seconds it kind of wants to power on, but doesn't. Last time (one month ago) I started it, it also started without choke, run very erratic, until I put the choke on, then it idled beautifully, and ran very nice afterwards.

Any ideas or suggestions would be appreciated!


__________________________________________________
1987 BMW K100, VIN:0093523
    

92KK 84WW Olaf

avatar
Life time member
Life time member
Use the choke to start it!


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 37,190 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 39.885miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Check the crankcase breather hose and the throttle body air caps for cracks. Air leaks can make the starting air mixture too lean to ignite.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

gorio

gorio
Silver member
Silver member
Remove then old fuel from the tank and add new. If that is not possible at least add a little menthol alcohol to the mix.

Pull the fuse for the fuel pump and pull the spark plugs. Crank the engine over for several short bursts. This should help remove oil and fuel from the cylinders.

Dry the spark plugs before re-installing. heating them with a lighter works. Just remember the fuel on them may light up.

Put everything back together maybe checking again for spark before re-installing the fuse for the fuel pump.

Pull choke to the second notch and crank, again in short bursts.

Does it fire at all or just crank?

If it is still cool in your part of the world the oil and gas that has made its way into the cylinders will take a very long time to evaporate on their own. The above should help.

This may not be the cure but it would be a good start.


__________________________________________________
1992 K100rs 16v
1997 R1100rt
2006 R1200rt
Past lives
Kawasaki Concours
1976 BMW R90s
1975 Ducati 860gt
1992 Honda VFR750
1985 Honda VF750
1982 Kawasaki 750GPZ
1975 Norton 850 Commando
    

Laitch

Laitch
Life time member
Life time member
@gorio wrote:Remove then old fuel from the tank and add new. If that is not possible at least add a little menthol alcohol to the mix.
The advantage of using menthol alcohol is that it sweetens your breath.  Smile

Some garage environments promote condensation in the fuel tank which will degrade the fuel. Like gorio indicates, suck that old fuel from the tank, add fresh fuel, charge up the battery then start your moto. Next year when you put it up for winter, fill the tank with fresh fuel and add fuel stabilizer like STA-BIL. When spring comes, your moto will probably start.


__________________________________________________
1995 K75 81,000 miles
K100 won't start after winter sleep Usa-lo10
    

gorio

gorio
Silver member
Silver member
@Laitch wrote:
@gorio wrote:Remove then old fuel from the tank and add new. If that is not possible at least add a little menthol alcohol to the mix.
The advantage of using menthol alcohol is that it sweetens your breath.  Smile
>Mi spelin not alwies so good


__________________________________________________
1992 K100rs 16v
1997 R1100rt
2006 R1200rt
Past lives
Kawasaki Concours
1976 BMW R90s
1975 Ducati 860gt
1992 Honda VFR750
1985 Honda VF750
1982 Kawasaki 750GPZ
1975 Norton 850 Commando
    

Tarlin

Tarlin
active member
active member
Thanks for the advice, will try those things and report back!


__________________________________________________
1987 BMW K100, VIN:0093523
    

Tarlin

Tarlin
active member
active member
@Point-Seven-five wrote:Check the crankcase breather hose and the throttle body air caps for cracks.  Air leaks can make the starting air mixture too lean to ignite.
Do you maybe have a picture where the crankcase breather hose is located?


__________________________________________________
1987 BMW K100, VIN:0093523
    

Laitch

Laitch
Life time member
Life time member
This is a photo from a K75. The green arrow points to the coil cover at the rear left-side of the engine. Yours will look slightly different. The orange arrow points to the throttle switch. The hose is circled.
K100 won't start after winter sleep K75-le10


__________________________________________________
1995 K75 81,000 miles
K100 won't start after winter sleep Usa-lo10
    

10Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Fri Mar 26, 2021 10:53 am

92KK 84WW Olaf

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Life time member
Life time member
The circled hose is commonly referred to a the 'Z pipe'. They fail in time and cause very bad running. It can be replaced through that gap, have done 2 of them.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011171 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 37,190 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 39.885miles.

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

11Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Fri Mar 26, 2021 11:00 am

Point-Seven-five

Point-Seven-five
Life time member
Life time member
The Z-pipe is one of the first things I check when I bring a new brick into the fold. So far, I've replaced it on all but one of my bikes. The bends in that tube along with the hose clamps are tough on it.

One caution, you don't have to go nuts tightening the clamps on it. Just snug will get the job done, and doesn't damage the rubber.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

12Back to top Go down   K100 won't start after winter sleep Empty Update - it's alive Fri Mar 26, 2021 5:14 pm

Tarlin

Tarlin
active member
active member
Thanks for all the tips, I will definitely check and replace the Z hose, I just need to find a new one. Even if it is not the cause (yet), is is 30+ years old so replacing it would not hurt the bike:)

So, status update: before doing anything (except buying a fresh can of 100 octane gas, which will be need anyways), I decided to try one more thing, just like last year: I put the bike out of the garage, on the sun. Let it sit in the sun for about an hour, and then it started, without any drama.Did about 30km then, runs perfect. What puzzles me is the reason, why won't it start in the cold garage (still about 5-10 degrees Celsius inside, not ,minus, far from it)
I was trying to start it for 5 days, drove me mad. As soon as I let it warm up in the sun for about an hour, it started like it should. So I guess it is like it's owner, functions best in sunny weather:)))
It does bother me though, as I can't find the reason for that...


__________________________________________________
1987 BMW K100, VIN:0093523
    

Tarlin

Tarlin
active member
active member
One more thing: It started on "old" gas that I put in the tank end of November, before putting it to hibernation. Old gas was one of the first things suspected last spring, so I drained the tank, and put fresh fuel in it. Did nothing:) Started only after beeing left in the sun to warm up:)
What is funny is that in the autumn, on last rides, started without problems, even in lower temps. The problem just happens in spring after hibernation....


__________________________________________________
1987 BMW K100, VIN:0093523
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Condensation.

Sitting in the garage on a warm day in the early spring, water condenses and gets into everything. Putting the bike out in the sun for a couple hours dries everything out.

Usually it's the plug wires and the coils that suffer the worst. The water bleeds off the spark.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

15Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Sat Mar 27, 2021 12:10 am

gorio

gorio
Silver member
Silver member
Just curious as to how it runs in the rain?

I would try draining the bike or using fuel stabilizer next fall  and see how it goes next year.


__________________________________________________
1992 K100rs 16v
1997 R1100rt
2006 R1200rt
Past lives
Kawasaki Concours
1976 BMW R90s
1975 Ducati 860gt
1992 Honda VFR750
1985 Honda VF750
1982 Kawasaki 750GPZ
1975 Norton 850 Commando
    

Tarlin

Tarlin
active member
active member
@Point-Seven-five wrote:Condensation.

Sitting in the garage on a warm day in the early spring, water condenses and gets into everything.  Putting the bike out in the sun for a couple hours dries everything out.  

Usually it's the plug wires and the coils that suffer the worst.  The water bleeds off the spark.  
This sounds about right...what puzzles me is the fact that I have changed the sparkplugs, sprayed some contact cleaner in the ignition caps, but nothing. Only after being in the sun it started. Could be that the main source of the problem has been the igniton coil, as I have not touched that.


__________________________________________________
1987 BMW K100, VIN:0093523
    

Tarlin

Tarlin
active member
active member
@gorio wrote:Just curious as to how it runs in the rain?

I would try draining the bike or using fuel stabilizer next fall  and see how it goes next year.
I try to avoid riding in rain as much as possible:))) But I did go trough some heavy storms last year on roadtrips, and it worked without a hitch. I'm not sure we even have fuel stabilizers in EU, at least I never saw one:))) I put the 100 octane fule in the tank in Nov, and after it started again, used the tank without any issues, so that leads me to believe it was not the fuel.


__________________________________________________
1987 BMW K100, VIN:0093523
    

gorio

gorio
Silver member
Silver member
I put the 100 octane fule in the tank in Nov, and after it started again, used the tank without any issues, so that leads me to believe it was not the fuel.
I wonder what the attraction to 100 octane is? Did you know it is much harder to light then a lower octane regular fuel? It also actually contains less energy then regular fuel.


__________________________________________________
1992 K100rs 16v
1997 R1100rt
2006 R1200rt
Past lives
Kawasaki Concours
1976 BMW R90s
1975 Ducati 860gt
1992 Honda VFR750
1985 Honda VF750
1982 Kawasaki 750GPZ
1975 Norton 850 Commando
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
There are a lot of components and connections involved in making the spark on the K bike. Condensation can get into places you have a hard time even finding. A couple hours in the sun gets to those places.

Some of those places are the Hall sensors and their connector, the ignition control module under the tank and it's connector, the Jetronic and it's connector, and the connections and insulation around the coils.

Some of these parts are protected pretty well from rain and splashing water, but not water vapor in the air that can get into every nook and cranny. Capillary action also helps get the moisture into hidden places as well.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

Tarlin

Tarlin
active member
active member
@Point-Seven-five wrote:There are a lot of components and connections involved in making the spark on the K bike.  Condensation can get into places you have a hard time even finding.  A couple hours in the sun gets to those places.  

Some of those places are the Hall sensors and their connector, the ignition control module under the tank and it's connector, the Jetronic and it's connector, and the connections and insulation around the coils.  

Some of these parts are protected pretty well from rain and splashing water, but not water vapor in the air that can get into every nook and cranny.  Capillary action also helps get the moisture into hidden places as well.  
Thanks .75, this seems the most probable explanation! 

The bike is like it's owner, works best when exposed to sunny weather. 

In all seriousness, I really do think that condensation is the issue here, as I can't find any other logical explanation. The solution for two years in the row has been a few hours worth of drying out in the sun.

Change of spark plugs, battery, and fresh fuel brought no results, the Z pipe also seems ok, the only thing that helped was to let it sit in the sun and fresh breeze, and then it started like a champ, and has had no problems starting since then. Also tried it starting on a fresh morning since then (sub zero temp) and it exploded into life with ease.

So, my plan is to add fuel stabilizer(thanks @Gorio) next autumn (found it online), and see if that changes anything, and if not, just aim the low temp/high flow hot air heater onto the bike for a while, and then start it.

Thanks everyone for the tips and suggestions, sincerely appreciated.


__________________________________________________
1987 BMW K100, VIN:0093523
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
How tight is your garage where the bike is stored? Some ventilation is important to reduce the amount of condensation that forms over the winter and especially in the Spring.

I try to run the engines in my bikes a couple times a month during the winter specifically to keep the battery charged and to warm things up enough to dry out any condensation that might form. I let them idle until the fan has had the opportunity to cycle 2-3 times. After they cool off for a couple hours I put their covers back on them.

One other concern with condensation is the corrosion it causes on unprotected parts of the bike. It can be especially bad if the bike is stored in a garage with a car that is used on roads that are treated with salt. As a prevention, I give my bikes a good wash before the winter to remove any dirt that will hold moisture and then give them a spray with a corrosion protectant. S100 makes a good one. I spray everything on the lower half of the bike avoiding getting any on the brake rotors. A bonus is that opening the garage to remove the exhaust also helps to ventilate it as well.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

Tarlin

Tarlin
active member
active member
Actually the garage is a shed:) So there is plenty of room (could store 2 cars, only has the K100, a couple of bikes, lawn mover, and some garden tools), and no other motor vehicle inside. The bike is connected to the battery charger all the time during storage, and I did try to start is a few times in winter, but with no success (After storage it sat initially for one month as I was away for work).
The shed itself is insulated, but not heated.


__________________________________________________
1987 BMW K100, VIN:0093523
    

Holister

Holister
Life time member
Life time member
Could be either condensation as Point-Seven-Five suggests or maybe a temperature sensor issue.
I would start with making sure all your ground points are clean and bright. Ensure that the plug for your ignition control module at the headstock is clean and firmly in place with the rubber boot, and same for the ECU.
Check your temp sensor is in spec with a DMM. Instructions are in the Trouble Shooting page.
You say that the Z-pipe "seems ok".... well, mine looked ok first time I worked out what it was, but it was a different story when I took it off.
One place that tends to get corrosion badly is inside the coil towers.
When you're replacing the fuel in the tank, don't forget to flush the new fuel thru the fuel rail also.
It's seems a little weird. Hope you find out what's happening.


__________________________________________________

1989 K100RT     VIN  0097367 (naked)  
1996 K1100RS   VIN  0451808
  K100 won't start after winter sleep Austra12    Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

24Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Sun Apr 11, 2021 10:32 am

Laitch

Laitch
Life time member
Life time member
@Tarlin wrote:I'm not sure we even have fuel stabilizers in EU, at least I never saw one:
You have them for sure and this is not the only one on offer. Whether you use it depends upon how long your moto remains idle at a stretch and whether you use petrol with ethanol in it.


__________________________________________________
1995 K75 81,000 miles
K100 won't start after winter sleep Usa-lo10
    

25Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Sun Apr 11, 2021 10:37 am

Tarlin

Tarlin
active member
active member
Thanks @Laitch, I actually found this site trough another thread, and man...they have a lot of stuff for our old mules cheers. Might actually try the LiquiMolly stuff from the same site. A bit cheaper, and made by "ze Germans", so there should be no efficiency "lost in translation" Very Happy


__________________________________________________
1987 BMW K100, VIN:0093523
    

26Back to top Go down   K100 won't start after winter sleep Empty Re: K100 won't start after winter sleep Sun Apr 11, 2021 11:52 pm

Matthew-Brisbane

Matthew-Brisbane
Life time member
Life time member
Qustion 
What's a winter sleep  ? 

That the best time to ride  out here, clear blue skies, internal heat from the engine


__________________________________________________
1986 K100 RS Motorsport
#### K100 RS Project 
2011 R1200 GS
    

Laitch

Laitch
Life time member
Life time member
@Matthew-Brisbane wrote:What's a winter sleep  ? 
K100 won't start after winter sleep Winter10


__________________________________________________
1995 K75 81,000 miles
K100 won't start after winter sleep Usa-lo10
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
lol!


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

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