Author Topic: Phoenix Rising - '93 K75RT Fire Recovery  (Read 3491 times)

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #25 on: October 09, 2018, 10:08:41 AM »
I've been working on the assumption that my mystery wire is a ground wire.  But what if it isn't.  I found a picture of my positive terminal pre-fire.  It shows 3 connected wires to the positive terminal.  The main positive from the wire harness, a battery tender, and another wire (although it looks different than the picture above).





I don't have heated grips or an electric windshield and no other aftermarket add ons to hook up to the battery.  As it looks right now the only things connected to the battery are the main positive from the wire harness and the main ground.  Should there be anything else?
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline The Mighty Gryphon

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #26 on: October 09, 2018, 11:57:08 AM »
Look for a cluster of brown wires under a bolt on the left side of the frame about half way back from the steering head to the seat.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '92K100RS White, '94 K75S Dakar Yellow
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'94 K75S "Cheetos"
'91 K100RS "Moby Brick Too

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #27 on: October 10, 2018, 01:25:07 AM »
Look for a cluster of brown wires under a bolt on the left side of the frame about half way back from the steering head to the seat.

Thanks Gryphon.  I found it.  So does the ground wire connect from the negative terminal to that bolt on the frame?
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline Laitch

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #28 on: October 10, 2018, 06:20:17 AM »
It will connect to the bolt if the wire's ring terminal will fit over the bolt shank. Another question to ask is where is its other end?
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #29 on: October 10, 2018, 09:44:30 PM »
It will connect to the bolt if the wire's ring terminal will fit over the bolt shank. Another question to ask is where is its other end?

Where it connects is a great question.  I"m planning on taking it down to my local dealer and ask if they can help me figure it out.
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #30 on: October 10, 2018, 09:48:27 PM »
I'm coming up on the last few parts (fuel rail, injectors, coils, and plug wires). 
In the picture below can someone confirm the following?
  • the yellow circled plug doesn't connect to anything, correct?
  • the green circled wires are ground wires and I connect them to the ground under the tank, correct?

  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #31 on: October 11, 2018, 04:10:29 PM »
Where does this ground wire connect?  It looks to be about a 10 gauge wire. I can’t read the part number but it must be somewhere in the engine compartment area. Any ideas?



I took this cable to the my local dealership and their best guess is that it is from the CDI to the battery.  They said it was the "box up by the neck of the bike".  I looked and I see my CDI box and all I see is the wire harness that comes out of the box.  But the length isn't right, the cable would be too short to reach from the CDI to the battery. 

What's the risk if I just leave the cable off the bike?  Although I'm growing more convinced that it's a ground from the battery to the ground screw under the tank.
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline Laitch

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #32 on: October 11, 2018, 05:21:11 PM »
Although I'm growing more convinced that it's a ground from the battery to the ground screw under the tank.
What convinces you of that—testing, process of elimination, consulting I Ching? In wiring your moto, you seem to be demonstrating haphazard technique similar to the method of injector testing that landed you here in the first place. Strive to have understanding and logical reasons for actions being taken. A wiring diagram and a multimeter for testing continuity by using resistance should be in play here.

A ground wire from the battery leading to a common ground connection should be brown in an OEM harness, according to the wiring diagram. Is one of those wires fastened to the battery ground connection at its other end, or is nothing fastened anywhere? What did you take to the dealer for examination, that section of harness? The wiring diagram shows a brown wire from the battery to a common ground. Does your battery's ground post have a brown wire leading from it? If it does, check for continuity between that point of the wire and the terminal you've pictured.

The battery's ground connection wire to the transmission is black.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #33 on: October 12, 2018, 02:24:50 PM »
I found where that ground wire goes.  It connects from the ground under the tank to the ground on the gear box.  I found another thread on here that showed the exact wire and where it goes. 

I've now got all the electrical hooked up and replaced all the fuses with new ones.  All the dash lights work, indicators work, brake light works, and headlight works.

I followed the steps here (http://www.motobrick.com/index.php/topic,3781.0.html) to install the fuel injectors and to make sure that they don't leak (no leaks detected).  I can hear the fuel pump working and I can see fuel returning to the tank.

I removed the spark plugs, cleaned and checked the gaps.  I checked for spark on each by grounding it to the engine and pushing the start button.  Each plug has spark. 

I tried to start the bike but it won's fire.  I pulled the #1 spark plug and it was wet with fuel.

So now I have to solve my no start problem.  Off to search the forum for solutions.



  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #34 on: October 13, 2018, 01:44:56 AM »
I went through the steps in the "No Start-Slow Start-Whackness". 
  • 5 times I put the bike in 4th and pushed it backwards and popped the clutch
  • I cleaned the Jetronic, 4-pin connector, and the electrical connections for the FI
  • I don't have a side stand switch
  • I don't want to get into the ignition switch yet

Which should I do next?
  • Check the fuel pressure with a pressure test kit (I "rented" one from my local auto parts store)
  • Chase the 4-pin connector more
  • What else?

Here's a video of what the bike sounds like.


  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline Martin

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #35 on: October 13, 2018, 02:12:31 AM »
Check the temperature sensor and it's connection. If one or the other is faulty it can cause flooding and failure to start.

Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline The Mighty Gryphon

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #36 on: October 13, 2018, 05:56:45 PM »
I have found that if a cold engine doesn't start immediately it will flood.  Continued cranking exacerbates the problem.  If you suspect flooding, disconnect the four pin tank connector to disable the fuel pump and attempt to start.  This will blow the excess fuel out of the cylinders, and with a bit of luck, it may fire once or twice as the last of the fuel is removed.

Then reconnect the pump and try to start again. 

Another thing to try is adding a bit of oil to the cylinders to help get better compression.

  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '92K100RS White, '94 K75S Dakar Yellow
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'94 K75S "Cheetos"
'91 K100RS "Moby Brick Too

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #37 on: October 13, 2018, 06:13:24 PM »
I have found that if a cold engine doesn't start immediately it will flood.  Continued cranking exacerbates the problem.  If you suspect flooding, disconnect the four pin tank connector to disable the fuel pump and attempt to start.  This will blow the excess fuel out of the cylinders, and with a bit of luck, it may fire once or twice as the last of the fuel is removed.

Then reconnect the pump and try to start again. 

Another thing to try is adding a bit of oil to the cylinders to help get better compression.



I saw that video and tried that method as well to blow the excess fuel out.

I haven't tried the oil in the cylinder yet.  Do I just squirt about a table spoon of oil in the spark plug hole? 
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline johnny

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #38 on: October 13, 2018, 06:43:14 PM »
greetings...

do you reccommend convectional oil in the cylinder or that cynthetic oil...

j o
  • i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin...
:usa#1

Offline Laitch

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #39 on: October 13, 2018, 07:38:02 PM »
I saw that video and tried that method as well to blow the excess fuel out.
I haven't tried the oil in the cylinder yet.  Do I just squirt about a table spoon of oil in the spark plug hole?
The video Gryph posted and that you've copied into your post shows you how to use the oil and tells you how much oil to use.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #40 on: October 13, 2018, 08:53:45 PM »
The video Gryph posted and that you've copied into your post shows you how to use the oil and tells you how much oil to use.

My apologies to Laith and Gryph, I thought I had watched that video but it was this one I watched last night, .  Looks like the same bike and he talks about a flooded engine.  I apologize for not watching the video you posted and jumping to a conclusion.

I followed Chris's instructions and put in just under 10cc's of oil in each cylinder.  Cleaned and reinstalled the spark plugs and wires.  But the bike still didn't start.  Although it did spit out some nice smoke rings.  You can view them below.  I cranked the bike over until it stopped smoking and then cranked it for about 20 seconds with the fuel pump disconnected at the tank to to try to clear the cylinder of fuel.


  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #41 on: October 13, 2018, 09:00:52 PM »
Check the temperature sensor and it's connection. If one or the other is faulty it can cause flooding and failure to start.

Regards Martin.
Thanks Martin.  I'll look up some instructions on how to check the temperature sensor and connection and post back.
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #42 on: October 14, 2018, 08:49:22 PM »
It RUNS!!!

I tried the method mentioned by "Paul Mihalka" (5th post down) from the this post on advrider, https://advrider.com/f/threads/k75-wont-start.658520/.  It idles with the "clutch" throttle advance on the first setting like in the video below.  It requires a little throttle (less than about a 1/4 throttle) or needs to be on the second setting of the "choke" to start, but it starts consistently.  It needs a TB balance to smooth it out.

Thanks for all the help and advice so far.  I'm not ready to declare it road worthy yet but it's a whole lot closer than it was.

  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #43 on: October 22, 2018, 02:29:27 AM »
An update on the bike progress.

I got it starting and running consistently.  I had a significant air leak at the intake manifold added some gasket sealer and that took care of the air leak.  But it is idling smoothly.  I took it down the street to get some fresh gas and it ran smooth.

I tested the water temp sensor #10 & #13 pin on the EFI plug and it measured at 2.06 K ohms at about 70F/21C.  I think it seems a little low but is close to the 2.5k ohms I see posted.  Is that close enough or does that indicate I should replace the temp sensor?  I will need to pull the radiator to replace the fan soon so i can easily do the sensor at the same time.

 I still need to check the valves and balance the throttle body.

  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline rbm

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #44 on: October 22, 2018, 06:41:37 AM »
This one measurement seems ok.  I measured a brand new sensor's overall response and published the results as an Excel file.  At 21C, i measured 1,756 Ohms.
  • Regards, Robert
Toronto, Ontario

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Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #45 on: October 22, 2018, 07:27:39 PM »
Measured my Valve Clearances and here are the values I got.
Intake: 1) .13mm  2) .15mm  3)  .13mm
Exhaust:  1) .10mm   2) .10mm  3) .05mm

Those valves look pretty tight.  Looks like I need to pull a shim and take a look at it.

I measured all of them like the #2 exhaust with the lobes sticking straight out like in the picture below.

  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline Laitch

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #46 on: October 22, 2018, 09:19:20 PM »
Measured my Valve Clearances and here are the values I got.
Intake: 1) .13mm  2) .15mm  3)  .13mm
Exhaust:  1) .10mm   2) .10mm  3) .05mm Looks like I need to pull a shim and take a look at it.
Look pretty tight is an understatement! There is something radically wrong with your exhaust valve clearance numbers. The exhaust valve clearances should measure between 0.25mm and 0.30mm. Being 0.15–0.20mm too tight is recipe for rapid engine failure. Two of the intake clearances are tight and need adjustment but are not unreasonably tight like the exhaust valve clearances.

I'll look on the bright side and believe your technique is flawed or that I've wandered into an episode of Black Mirror. I can't tell anything by your photos. You seem to acknowledge that the nose of each cam lobe should be pointing outward more or less in line with its valve's stem when the clearance is measured. Which instructions are you using? Have you carefully viewed Harris's video? Are you using the special tools?

Remeasure. If you get the same results, you'll need to do more than pull a shim. You'll need to pull five shims and measure each with a micrometer to figure each replacement shim's thickness.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #47 on: October 22, 2018, 09:40:55 PM »
I'll look on the bright side and believe your technique is flawed or that I've wandered into an episode of Black Mirror. I can't tell anything by your photos. You seem to acknowledge that the nose of each cam lobe should be pointing outward more or less in line with its valve's stem when the clearance is measured. Which instructions are you using? Have you carefully viewed Harris's video? Are you using the special tools?

Remeasure. If you get the same results, you'll need to do more than pull a shim. You'll need to pull five shims and measure each with a micrometer to figure each replacement shim's thickness.

I'm really hoping my technique is flawed.  Below is a video of me measuring the #2 exhaust, maybe you can find something wrong with what I did.  I watched Chris Harris' video and I followed the directions in my Clymers manual, maybe I missed something.  When I first did the measuring the bike was in neutral and the manual says to do it 5 gear.  So, I put it in 5th gear and re measured everything and got the same results.

I do not have the special tools yet, I did send Ken an email asking if he's still selling them and that I'm interested in buying a set. 

  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

Offline Laitch

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #48 on: October 23, 2018, 02:54:28 PM »
I'm really hoping my technique is flawed.
. . . I put it in 5th gear and re measured everything and got the same results.
The only technique flaw I notice so far is that you’re buckling the measuring blade when taking the measurement. Choke up on it to the greatest extent possible.

If the cam lobe’s nose is in the correct position, it doesn’t matter whether the bike is in gear or not. Being in gear just allows rotation of the camshaft by rotation of the rear wheel instead of by wrench leverage on the camshaft flats like Harris is doing.

This tight valve situation might explain one of the reasons why the engine in your other video sounds to me like it's weak, and why your moto had performance problems from the beginning—intake leaks not withstanding. It's why a valve clearance check is the earliest of tasks to do on any used moto purchase rather than jumping from symptom to symptom first when engine performance is weak but riding desire is strong.

I urge you to obtain the shim/bucket tools for the procedure despite others here having used alternative methods because you need any advantage you can get at this point to help you. Maybe there is somebody near you who could mail them to you on loan.  They don't take up much envelope space.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline brichbk

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Re: Phoenix Rising - '93 K75RT Fire Recovery
« Reply #49 on: October 23, 2018, 04:55:50 PM »
Thanks For the feedback, Laitch. I agree that the valve issues might be the issue behind all the other issues.

 I ordered the tool this morning from Ken Lively so later this week I can work on getting the shimms out and measuring them to find new ones.
  • Central Valley California
  • 1993 BMW K75RT // 1982 Honda Nighthawk 650sc

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