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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: restinthesun on May 24, 2019, 08:27:46 AM
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I've got a classic case of no start whackness. Been through all the no start pages on here and other forums and can't figure it out. Ideas appreciated! Summer's short here in Vermont. Here's the story:
An otherwise dependable 88 K75S that I've had for 3 years (70K miles, about 20k mine). Sat indoors all winter, started right up, but didn't want to start very easily after. Thought it was just a low battery so ran for 20 miles. No issue. Next time wouldn't start for love or money. Found some light corrosion on spark plugs (indicative of something?) so changed all of them. Attempting to start, felt like it wanted to go but just wouldn't turn over. Railed on starter for probably a little too long in hope it would got. Was so close. Fuel pump goes. Battery is charged up. Gas is fresh. Grounds checked. Mototronic plugged in good.
Thinking about the spark wires but don't want to spend the money if not needed. No way to test the current OEM ones, seemingly... Ideas?
Will grab a video and post this weekend.
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. . . Fuel pump goes. . . . Ideas?
The fuel pump runs, but is fuel being pumped through the line? Fuel filter is the easiest place to start. Is it clogged? Also, be certain all the fuel line connections within the tank are tight and no lines leak.
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Thanks, Laitch. That's a good call. Fuel filter probably needs a changing. I'll dig around in the tank to see what's happening. We should get a ride in this year.
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Was that a giant granola bar on your moto at the App Gap lookout? :giggles
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Something like a ground up stone granola bar :giggles was surprisingly stable with some paracord.
Miss that commute everyday!
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My money is on water in the gas. Drain the tank, change the filter for a venerable NAPA 3032 and refill with fresh gas mixed with Techron and a bottle of Heet. Might take some cranking to get the water out of the rail, but that should make it run like it's supposed to.
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I should be able to knock that out in a morning this weekend and be getting my no-whack ya-yas by Memorial Day.
Thanks all. I'll let you know how it goes.
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have you checked for spark at plugs? You can just pull one lead, stick a plug in it and ground it to frame or engine with a jumper cable. make sure you have good ground connection.
Bright, blue spark is what you're looking for.
If you can do this in a darkened space more the better, you'll better see the arc across gap and color/condition of the spark.
g'luck
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Right. New battery. Checked all wires. All throw sparks. Tank is spotless. Now getting scary slapping noise from near transmission when I turn over. Wants to go but cant. Help.
Cant seem to post video from iPhone.
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Now getting scary slapping noise from near transmission when I turn over.
Cant seem to post video from iPhone.
Try not to let fear override clarity. Did you replace the fuel, change the filter and check the fuel lines? I think your battery is losing power. Keep it charged for this exercise. Post a video to YouTube then post a link to it.
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Deep breaths and walk away for a while. It's one of those days where nothing wants to works as it should. Grr.
Battery is brand new and on tender. Plenty o juice. Looked in the tank and no apparent issues. Spotless. No sediment. Fuel filter was changed less than 20k ago.
Here's what she sounds like. Someone else thought it was the alternator cup busted or perished Monkey Nuts inside the cup.
Thoughts appreciated.
https://youtu.be/i8vKRCHEWZo
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Pull the plugs are they wet or dry?
Regards Martin.
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When I pulled them today to check all of them gave a spark, all were dry (all sparked), but the one toward the back of the bike (right side) seemed to have a darker hue. Can't remember if it was wet per se.
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If the plugs are dry after you've cranked the engine repeatedly trying to start it, it would seem they're not getting fuel. Is fuel flowing at pressure when the starter button is pressed? Is the battery's resting voltage around 13V?
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Are you sure the pump is working? A lot of no start problems can be traced to intermittent four pin connector. Mine was fine for around 20 years but started to play up working intermittently. Even cleaning with DeoxIT only worked temporarily, I ended up replacing the connector with a waterproof 4 pin connector.
Regards Martin
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Had that problem a few years ago, Martin, and replaced with trailer hitch 4 prong. Worked a treat. Shouldn't be an issue, but will check for corrosion. Will check plugs again, change out fuel filter and see what happens. Will move onto alternator after.
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Here's my suggestions to check. I tend to agree with Laitch, if your plugs are dry either--- pump is not running, or the injectors are not working.
Check for +12v power on fuse #6 when trying to start. This fuse is for the fuel pump and the control power of the fan temp control relay.
If you do not get power here, the fuel pump relay is not closing, or the contacts are not making.
Check the multi-pin connector on the Jetronic controller, make sure it's clean. I've had issues with this on the Motronic of my 1100's. Prevented my fuel pump relay from running the pump.
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Thanks Scott. The plugs were dry with a gray dust indicating fuel had reached them and spark had fired. The fuel pump spins, the motor wants to go, and I can smell burnt fuel, so I don't think that fuel getting there is the issue. The plugs were brand new so any color means spark contact was the theory I was going on. Still need to drain and change fuel filter, but I'm most concerned about the slapping/cracking noise coming from the alternator (see video).
Thoughts on that appreciated.
The Jetronic is clean as a whistle. Don't think that's the issue either.
Will check for 12v on the fuse to x that out. I was having some issues with overheating last year if I idled for too long after a highway run, but didn't think that'd affect starting from cold.
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The plugs were dry with a gray dust indicating fuel had reached them and spark had fired. The fuel pump spins, the motor wants to go, and I can smell burnt fuel, so I don't think that fuel getting there is the issue.
How does the motor indicate it wants to go? Does the engine pop, smoke or what? Your interpretation of what's happening with the plugs might not be accurate. A "spinning fuel pump" is not evidence of a working fuel pump; it's evidence of a working fuel pump motor. Its impeller might be defective; its inlet might be clogged; its check valve could be defective.
It has been recommended that you check to see if fuel is coming through the line at pressure. It was also recommended that you check the fuel pressure regulator vacuum line for evidence of fuel. Have you done either?
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Sounds like a fuel delivery issue to me. The fuel sold today will leave behind brown clumps of goo that clog a filter very quickly. Can't tell you how many filters I went thru when I first got my K1100.
I know how our minds can wander when there's a no start issue. I'd start with the simple stuff first(check pressure and filter). Stick with it, you'll get it to start.
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Thanks, BigB. She'll go. I can feel it. I would love to think it's fuel delivery. I use ethanol free hi test almost exclusively and I couldn't see a spec of dirt in the bottom of the tank. When I get another few minutes, I'll unhook the filter and turn it over, If fuel comes through it, I can X that out, correct? ... or move on to the injectors...
When I get the filter out I'll cut it open for science.
When I say the spark plugs are dry, I meant they're dry with expended fuel dust. Fuel is getting there, but she's not turning over more than once or twice. I put oil in the spark plug inlets and it smoked. It burns fuel, but maybe not enough... Sorry if I'm not the best at describing this. Really appreciate all the input.
All that said, that slapping/whacking noise coming from around the alternator is new and not at all normal. Sounds like something has broken from where I stand. Laitch, you said you can't hear it? It's right at the beginning and the end. Pretty distinct.
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Pull the alternator and check the monkey nuts. They are known to break down over time. The nuts are compartmentalized by alloy fins if the nuts are gone the fins will break off.
Regards Martin.
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Laitch, you said you can't hear it? It's right at the beginning and the end. Pretty distinct.
Your definition of scary and mine differ. I guess I'd need to be next to it with my ear trumpet. :giggles
In the video, I don't hear enough combustion to dry the plugs. Just remove the cap assembly, press the starter button and see how much fuel return you're getting. If fuel is pouring down from the ceiling of the tank (that would be a modification to your year's setup) or the fuel in the tank is being agitated by returning fuel entering through the return port in the floor of the tank, the pump probably is working. If that's the case, what might not be working is the signal from the fuel injection relay to the injectors. Substitute the horn relay for the injector relay and see what happens.
I don't think there's fuel in the cylinders. Whatever is the cause, this is as exciting as being the 88th person in the Death Zone line to summit Everest, although I just started a fire in the woodstove so there seems to be enough oxygen to go around.
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There is a balance shaft on the K75 that is driven from the output gear through a sloppy dog and slot. If the engine is misfiring on a cylinder, the dog will bang around in the slot and make a horrible racket. On some engines(like my K75RT) even when the engine is tuned and running perfectly it will bang around between 1200 and 1800 rpm. (I suspect there is some sort of resonance that causes it at that speed.)
As far as I know, after 40,000 miles of listening to that banging the engine still runs fine.
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Ok the ethanol thing doesn't apply to this situation. I can hear what the clacking in the video, with headphones on, and it sounds exactly like what Gryphon is describing. Maybe it's me, but your battery is sounding weak. A fully charged battery would make my 1100 turn over fairly quickly.
I remember my bike sounding like yours. My issue came down to not enough acid in my brand new battery. Motor would turn over and puff a little, but wouldn't start. She fired up the next morning after topping off the acid and leaving the battery on the charger overnight. Keep at it, hopefully it's a fairly simple fix.
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Update: Still not working. FML.
I checked the fuel delivery and all seems to be working. Drained tank, refilled with Super 93 and HEET. Tank is spotless. All connected as should be. Changed the filter. Took off gas line to injector rail and fuel happily spat out when I hit the start. Had pressure. That means the Fuel Injector relay is good, correct? That tick those boxes, Laitch?
The "wants to go" comment came from the few ignitions, or pops, I could hear and smell. Seemed to burn once or twice then stop. When I put 10ml of oil in the spark holes, it smoked. Logical that it's got spark and fuel, no? Will try to capture on video next I'm at the bike. Probably easier that way.
Battery is brand new and tested for 12.8V. All sparks new, visual confirmation they sparked against a ground, so not spark wires or coils, seemingly.
Other ideas happily accepted. Injectors gummed up? Way to test that?
The Whacking at start up is new and sounds terrible to my sensitive ears. I've had the "whacking after warm up" which I believe I enquired about here. It goes away when I pull the clutch and seemingly wasn't an issue. If it's just the alternator, would it stop the bike from starting?
My radiator fan never worked so great. She always wanted to overheat if I did a 25 min highway stretch and then sat in stop-go traffic for any length of time. Was planning on checking/replacing radiator or temp sensor. That shouldn't affect start up though, right?
Thanks, all.
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That means the Fuel Injector relay is good, correct? That tick those boxes, Laitch?
The injection relay still could be malfunctioning. It was suggested you swap it to find out. It was also suggested you check the fuel pressure regulator vacuum line for fuel infiltration. Have you done either of those checks?
There are already posts about how to check injector function by removing the rail with them still attached; that is, however, one of the classic methods of igniting your moto if you aren't careful. :giggles
I don't consider the radiator fan or alternator directly related to the starting problem.
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If you crank the engine over with a fully open throttle they normally flood. Try cranking over with a full throttle then check the plugs they should be visibly wet.
Regards Martin.