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K100-forum.com » Technical, repair and troubleshooting » Engine and transmission » Anyone know why this is running so rough?

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timz10000

timz10000
Silver member
Silver member
My bike's been sitting for a few months. I had gotten water in the gas tank and it was running rough, then the battery died. (It had gotten dumped on by rain when I went out of town for a few days, and my gas tank gasket lets water in)

I just got a new battery, drained and re-filled the tank and replaced the fuel filter. 

Now it's running rough like this - any ideas about how to start troubleshooting?


 


__________________________________________________
1985 K100
    

duck

duck
Life time member
Life time member
Inspect the spark plugs first.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

3Back to top Go down   Anyone know why this is running so rough? Empty Rough Mon Apr 06, 2020 6:02 pm

daveyson

daveyson
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Life time member
Also, you emptied the tank but there is probably some water in the fuel lines and rail. Running it for a while might clean it out, metho can also help, it absorbs moisture that might be left.


__________________________________________________
11/1985 BMW K100RT (late model)  Vin. 0090567
 ~120,000 km
    

MartinW

MartinW
Life time member
Life time member
If the tank cap is installed back to front the drain hole for water is covered. There is a notch in the base that aligns with the drain hole on the tank.
Regards Martin.


__________________________________________________
1992 K75s
    

timz10000

timz10000
Silver member
Silver member
Truly appreciate the advice. 

OK, so now I drained the fuel from the lower hose and the fuel rail, and changed the spark plugs that were fouled. Here's what it's running like now. Does this seem like a problem? Or do I just need to ride it around hot for a bit to burn out whatever's in the fuel / exhaust system. It doesn't start easily. 

Also here's a pic of the fouled spark plugs I replaced in case that tells me something. (I gapped the new plugs at .6-.7 mm as per Clymer's)
: Anyone know why this is running so rough? Spark-10


__________________________________________________
1985 K100
    

Stumpy

Stumpy
Silver member
Silver member
It sounds okay to me. I would suggest that you take it out for a run to give it a blowout, the blue smoke is likely to be oil from the bike being on the side stand or remnants from the poor running that remained in the exhaust.


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BMW K100RT 0095857
    

Suzi Q

Suzi Q
Life time member
Life time member
I've found that if the bike's not been running properly for any reason and fouled its plugs, they can be very difficult to clean and can end up being 'the problem' themselves. It takes (me, anyway) a lot of patience to properly clean out the crap right down in the bottom of the gap around the porcelain. Just wire brushing won't do it. Otoh, if the bike is at least running well enough to ride, then the 'proper thrashing' method seems to work fine.


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Sometimes I'm not really Suzi Quatro.
    

92KK 84WW Olaf

avatar
Life time member
Life time member
Italian tune up needed....


__________________________________________________
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 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

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
    

Suzi Q

Suzi Q
Life time member
Life time member
Very Happy Long time since I've heard that expression!


__________________________________________________
Sometimes I'm not really Suzi Quatro.
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
92KK 84WW Olaf wrote:Italian tune up needed....
 4 new NGK D7EA plugs, 6 ounces of Techron Fuel System Cleaner in a tank of fresh no-corn fuel and a couple hours at 75-80mph. 

Chris' comment on fouled plugs is spot on.  I had a new set of plugs that got fouled pretty bad by wrong injectors(don't ask) that wouldn't work for more than one start and a couple minutes of running before I had to clean them again.  If you get the D7EA's get 4 terminal nuts for the top so thye work with the plug wires.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

11Back to top Go down   Anyone know why this is running so rough? Empty Update: new plugs fouling, won't start Sat Apr 11, 2020 12:32 am

timz10000

timz10000
Silver member
Silver member
I realize this may be a matter of just getting it to start so I can execute the old Italian Tune-up. 

But after running it in the last video, I can't get it to start again and the new plugs are getting fouled. I'm going to keep trying to get it to go (I hear an almost-ignition-sound). Anything I can read from the new plugs getting fouled? Any suggestions for how to get it to start?

What would account for it getting fouled like this? Or is that just oil that seeped in over the months it was sitting, and I just need to get it started and go riding and burn all that stuff out?


Anyone know why this is running so rough? EUdwMuDgVJ24J56ZGkObUbKiq37_hX59fcO8O-idVxEx5AkDRCoHkVsPhXQSPnfTFVG1HZSKUZGZmkF7Lp34AjD3jp5goB6AReXi7izPMof7K7KUhHEyH3V1xWTaLQo_LNTiiFy0SL6K9TOdfOoWOszQFitSYwGiTwjznUUsV0tzKGWFESl36xtCLz_nHYV9EEvT1I0cfueZY56NKEXU6ACf1Sjkxqw9XEE44g_DX-VEJDlMwvDm-FTXaF4gsIR-gncM7b4i4z6rz5hl6ay_I0n-qANtdrXJgAOqQ6ffxO3lMTULuIYLuUXoqmQj6MqG6pGxzEA9BOIwqb3R5Hg4Sr7wKr4BNN461T9NaNHHYQipkYashkaKFdjgMKpDyeZIEJrUipJihJuIUvgfjbIpUNjRQsR29Ga8wFWT6VH4iTzjgNfXuAXV_QwvXqTxKHx4_cPQf4xcZ2G619PCzhtv6-3XD0j2Yyem0ygHg5irwrWFjqFKRRH0zYs9bzJQyqJSA6xVHY8R9HpGtE47XBMoizI2B7uM6Yav96kbcWcftPoXAKNDu9ckRljs87Fh2pMh_4dr1S5UYsjJYEG8KZFw_t17FxOEMaE8dgPY2-lfZxqhy1Jxo46Vr8PIEl_lE4ujN-mcM_bFe8bo0XdbamcxAn1BatFSQUM87M8muMg9WujD2EbGLDvaOYEfbOEQuA=w500-h666-no


__________________________________________________
1985 K100
    

MartinW

MartinW
Life time member
Life time member
After trying to start are the plugs wet or dry? Earth the plugs do you have a good spark?

Regards Martin.


__________________________________________________
1992 K75s
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
I don't know how an engine that won't start can foul the plugs.  Did it run at all on the new plugs? 

What kind of plugs did you get?  NGK D7EA's?  Did you get terminal nuts?  They won't fire reliably without them.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

timz10000

timz10000
Silver member
Silver member
I got NGK 7162 plugs with terminal nuts. Later today will check for spark on each plug. Also I used the recommended .6 -.7 mm gap in case that figures in


__________________________________________________
1985 K100
    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Did the engine ever fire with the new plugs? 

I suspect it did for at least a little while.  Plugs won't foul unless there is combustion.  Otherwise they just get wet and stay clean.

Have you checked the cold resistance of the water temperature sensor?  Should be around 2500 ohms.  I would check it at the terminals on the big ECU connector.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

16Back to top Go down   Anyone know why this is running so rough? Empty Leak in the fuel system - ruh roh Sun Apr 12, 2020 5:48 pm

timz10000

timz10000
Silver member
Silver member
Oooohkay I found the problem or at least part of it.

Looking into the tank with the gas level low, I see that when I turn it over fuel is leaking out of the fuel pipe inside the tank, squirting out from the bottom side under where I've circled - must be a crack in the pipe.

Darn. Is that something I could get repaired? Or do I need a new tank? 

Seems like that would explain why I seem to be getting spark but not ignition, right? Not sure how it ran the other day.

Anyone know why this is running so rough? Screen13


__________________________________________________
1985 K100
    

MartinW

MartinW
Life time member
Life time member
You could shorten the pipe and lengthen the hose. You could also slide a short piece of hose over the leak and clamp either over the leak or either side of the leak.
Regards Martin.


__________________________________________________
1992 K75s
    

Dai

Dai
Life time member
Life time member
As Martin says. I have a tank where it looks like exactly that happened and a PO shortened the ally pipe. He also managed to squash it a bit in the process but obviously not enough to affect fuel circulation.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

duck

duck
Life time member
Life time member
Been there, done that. On my 86 K75C turbo some idiot had moved the fuel and filter out of the tank and mutilated the piping.  I was able to cut that pipe up near the front the tank with a Dremel and move everything back into the tank where it belonged.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

MartinW

MartinW
Life time member
Life time member
Shortening the pipe in the confined space is going to be awkward to say the least. If you don't have a Dremel it can still be done. To stop the pipe from deforming make a plug out of wood that can be inserted into the pipes up to the leak. Use a fine tooth blade or part of a blade and go slowly, very slowly applying as little pressure as possible while still cutting the pipe. Once cut, clean up with small files inside and out, and clean out any metal.
Regards Martin.


__________________________________________________
1992 K75s
    

21Back to top Go down   Anyone know why this is running so rough? Empty Going to try it Sun Apr 12, 2020 8:45 pm

timz10000

timz10000
Silver member
Silver member
Sounds good. The pipe is also welded to the sheet metal support, but I think I can cut it away. I have a dremel, I'll be very careful...


__________________________________________________
1985 K100
    

lion1453

lion1453
active member
active member
timz10000 wrote:My bike's been sitting for a few months. I had gotten water in the gas tank and it was running rough, then the battery died. (It had gotten dumped on by rain when I went out of town for a few days, and my gas tank gasket lets water in)

I just got a new battery, drained and re-filled the tank and replaced the fuel filter. 

Now it's running rough like this - any ideas about how to start troubleshooting?


 



I HAVE SAME PROBLEM few Years it was the fuel hose had a little kink

    

warmshed

warmshed
active member
active member
Watch out using a Demmel in the tank, they  spark while running and could well ignite the fumes. You will need to empty the tank then fill with water, drain and fully vent the tank before putting sparks (from the commutator) inside the tank. Even then I would be wary.

    

moriarti

moriarti
Life time member
Life time member
The Demmal can be put in plastic bag /clingfilm,to be safe.Extinguisher Co2 if handy or rubber pipe from kettle for steam into tank,either will keep you safe Very Happy


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1984 k100 rs red/black VIN  0004449 Now sold to Olaf
    

warmshed

warmshed
active member
active member
moriarti wrote:The Demmal can be put in plastic bag /clingfilm,to be safe.Extinguisher Co2 if handy or rubber pipe from kettle for steam into tank,either will keep you safe Very Happy
Well done, that's much easier, its essential that you do something.

    

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