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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: andwew on December 18, 2014, 02:04:33 PM
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Hey buds!
New problem with my K75 bike:
So, I had some battery issues earlier. Replaced with the Odyssey Battery PC680 (as ya'll suggested) and got some new spark plugs. Boy, was my bike running well.
Last night I pulled into a gas station and filled my tank up. When I started the bike up again it started sputtering... Very inconsistent and the rpms were getting harder to keep up. I was close to home so I rode through it and it only got worse. By the time I got home it died... Now I can start it up, but I have to rev it hard to turn it on and keep it going. Bad news. :musicboohoo:
So! Here's the thing. I threw a little bit of that stupid Techron Concentrate Plus Fuel System Cleaner in my tank a few days before... Maybe it broke down some carbon and it clogged my fuel filter? Maybe it clogged my fuel injectors? I looked inside the tank last night and it is SUPER clean. I imagine that doesn't determine whether or not the fuel filter will be clogged...
These are my first two suspects.
Then there's the valve clearance? Never checked that but I read that this could lead to a similar issue?
Otherwise, I don't know what this could be.
I'm going to order these guys:
http://www.ebay.com/itm/BMW-K75-K75T-K75C-K75S-K75RT-Fuel-Injectors-Ultimate-Upgrade-Bosch-4-Hole-Spray-/191450932328?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c935d6468 (http://www.ebay.com/itm/BMW-K75-K75T-K75C-K75S-K75RT-Fuel-Injectors-Ultimate-Upgrade-Bosch-4-Hole-Spray-/191450932328?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c935d6468)
and a new fuel filter and really jump into it this weekend.
Sadly, this is my only form of transportation, so hopefully i can get this sorted this weekend.
Any advice\ pointers? This is a relatively knew bike and I'm not perfectly clear on the history, so any advice is greatly appreciated!
Thanks guys. :2thumbup:
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If it were me I wouldn't spend any more money until you get some diagnostic tips to work from. I would say it's definitely not the valve clearance -- thAt wouldn't cause an abrupt change like you've described.
Fuel filter is a likely culprit and a super cheAp fix so pull it and blow thru it...it's a good idea to replace it anyway if it's a new to you bike and it's not been replaced in your tenure. If that's not it...post back and I'm sure you'll get loads of tips here. Throttle position sensor comes to mind -- such an abrupt change doesn't point to rubber bits which generally crack and fail progressively rather than all at once. Also, make sure it's running on all 3 cylinders. If it's not, you may have bad spark plug wires. Look on euromotoelectrics or beemerboneyard for replacements or the realm imports from the UK.
So I'd say check the fuel filter and spark plug wires and report back and take it from there...
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Btw in case you've never done it, an easy way to check the spark plug wires is to put bike on center stand, unscrew the spark plug cover, toss a blanket over the headlight and run the bike and look for flashing light...if you see one then the spark is arcing off the cable and not getting to the plug.
If that is the case and you're running on 2 instead of 3, you can easily flood the engine and wet the plugs, which means it won't start until they dry out. Too much of that can foul the plugs -- wouldn't hurt once you get it fixed to pull them and gently clean them with gas and a brush then air dry.
If you have the original OEM wires, replace them now because they will fail soon if they haven't already. Don't replace with horribly overpriced OEM...aftermarket does the job for less than 1/4 the cost.
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I am not familiar with what happens when the fuel pump dies on a K bike but what you described kind of sounds like a dead fuel pump.
Again sorry to be vague but there should be a output line from the tank (there is also a return line), disconnect that and run it to a fuel proof container, turn on the key, the fuel should flow in a solid steady stream.
I have never done this so the test may not work. Also don't assume the pump is gone, electrical connection problems seem to be common.
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I say +1 on fuel filter, take it out and put in a new one, DON'T order injectors!!!!!! Good way to check fuel pump id turn the key and then hit starter, do you hear a whirring noise? If yes the pump is working, if no, check further, fuse etc. But given the way yours acted, I guess fuel filter. And it is cheap and quick to change. Take off the fuel filler lid and the four screws and your hand fits in there nicely, unless you got ham fists!!
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If the fuel pump wasn't working at all he'd get no fuel and it wouldn't run at all. The reason I say to blow thru he filter is that if you can't get air thru it then you know immediately that was the problem. I had a filter that was so clogged not even air would pass. An unclogged filter will let air pass up obstructed.
If air passes then while a new filter is a good idea, it's probably not the problem.
Btw fuel treatments are fine...Johnny o is rumored to take Techron in his morning coffee. So don't worry that you did something bad by adding fuel treatment.
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Having had a fuel filter split on me this year, I'd go with that first and take it from there.
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I'd check that gas...
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Could be a fouled plug again. Happens when you shut down and start back up sometimes. Could also be bad gas or some water in the bottom of the tank got stirred up when you added gas. That could be what fouled the plug, usually you can cure that with an italian tune up but not always. Add a can or Heet to take care of the water.
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+1 on this. :bmwsmile
I'd check that gas...
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Gentlemen!
I spent some time with the bike this weekend. Siphoned the gas out and replaced the fuel filter and re-seated the spark plugs. Seemd the fuel filter was clogged. Not bad but enough to give me my problems.
Once again, running very well.
I have my suspicions about it taking a while to warm up and really having to ease off the idle adjustment switch from the highest position. But otherwise all good!
Thanks guys! Good place here. :riding:
I'll probably be posting with another problem soon :yes
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A friend with a modern(ish) fuel injected Triumph Tiger had a very similar problem and was blaming the gas station for selling bad fuel. Turned out it was the water drain from the fuel filler area on the tank that was blocked. Over time rain water could not drain from the cap area and ended up overflowing into the fuel tank. When he stopped to re-fuel the water got stirred up in the tank and settled at the bottom and got sucked into the engine. The result was much coughing and spluttering from the bike and my friend as he ground to a halt less than a mile form the gas station!
Have a check of all the drain and breather pipes near the fuel cap area.
Cheers
Robert
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Check the rubber support for the fuel pump. They are going on these old bikes with the junk gas sold the last 15 years.