KLX650 riders UNITE

Discussion in 'Thumpers' started by COBAUM, Aug 17, 2006.

  1. Kurt138

    Kurt138 Adventurer

    Joined:
    Aug 26, 2015
    Oddometer:
    10
    Location:
    Reno
    I have a '93 KLX650C and have used both the OEM longer steel swingarm and the shorter R model Aluminum swingarm. I know you have an R model, but for anyone else that is interested you can't just put an R model swingarm on a C model. If you do that your rear tire will contact the C airbox at full compression. I verified this in offroad testing, ha. So I also installed an R airbox, shock and linkage - subframe modifications including battery relocation were required - and laced an 18" rim to the OEM C model cush hub. Long story short, none of that affected highway stability as far as I could tell. I've found that highway stability is just tied to what type of front tire I am using. If it is a 90/10 ( for example a D606) I get headshake on the highway around 70 mph with either swingarm. If my front tire is a 50/50 my bike feels completely stable on the highway with either swingarm. BTW, if I am running with a loaded GiantLoop Mojavi the headshake problem with a 90/10 front tire goes away - I tested that up to 95 mph on the highway as well.
  2. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

    Joined:
    Mar 23, 2009
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    Guys,

    HELP PLEASE!!!

    Major issue that I can't solve. My carb is pouring gas out the hose on the bottom of the float bowl. Not the overflow on the side, but the hose on the bottom (also an overflow I found out).

    At first, I thought it was the drain screw, nope, that seals properly.
    The I thought it needed a cleaning, still having issues after a good cleaning.

    Tried to fix by:
    New All Balls carb rebuild kit (for R model to get the good needle)
    This had new jets, needle, float valve, gaskets and some other bits
    New Float
    Polished the float valve seat (I had a nice rubber polishing bit for my Dremel that fit the seat perfectly, it shines like a mirror)
    Soaked the carb in Seafoam and cleaned everything, blew out with compressed air

    I have had this carb off 4 times and it still leaks gas. Sometimes it will stop or slow to a dribble, but always comes back. I though the needle was sticking, so replaced (the old one was bad). Then I thought the float may be cracked, hence the new one.

    The last thing I tried is to set the float height to specs. It is .69" (17.5mm) exactly using my dial caliper

    It stops when I turn off the petcock, starts immediately after the bowl fills. So I know it is an overflow problem

    Did I miss something, blow some seal out when I was blowing out the carb?
  3. Tinter

    Tinter Adventurer

    Joined:
    Feb 13, 2021
    Oddometer:
    43
    Location:
    Denmark
    To my knowledge it could be the drain screw, but sounds like it's fine.
    You say it starts when you turn the petcock, it fills the bowl and then it spills. Sounds to me like it would be the float needle.
    I've had the same issue when I thought to change the needle "Since I'm here anyway", but my carb kit was for a different Kawasaki. Seal was interchangeable, but not the needle.

    I would think your issue is the float needle in some way. In the float bowl you'll see a hollow rod sticking up and if the fuel gets above that it'll just spill out, indicating that you seem to get a continual flow of gas into the bowl.

    Maybe a bad float bowl seal, but I don't even think the fuel line reaches above that.
    Can't offer more help than that.
  4. markk53

    markk53 jack of all trades... Super Supporter

    Joined:
    Dec 20, 2007
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    It is either the float needle, it is the float set too high, or the overflow tube in the float bowl that allows the overflow is loose or missing... if it is this style of float bowl:

    [​IMG] that little brass tube is missing or leaking at the bottom.
    MasterMarine and Tinter like this.
  5. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

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    Replying to myself.

    CHECK THE GAS YOU MORAN!

    Yep dirty gas. Actually sediment in the tank cause I just filled it. Poured gas through one of them blue Scott towels and saw some gunk. Shook the tank and MORE GUNK!

    Had to give the carb a good flush as there was a thin piece of gunk abut 2mm long and .25mm diameter stuck to the side of the float needle valve.

    Added in a in-line fuel filter and no leaky.

    Back to your regularly scheduled stupidity.
    Chris-KH2PM and Tinter like this.
  6. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

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    Mark,

    Thanks. I thought the same thing, that is why I went back in one more time, to check that. Found the above.

    Simple stuff always gets us!
    Tinter likes this.
  7. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

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    Thanks for the validation.
    Tinter likes this.
  8. Tinter

    Tinter Adventurer

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    Feb 13, 2021
    Oddometer:
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    I was staring into my float bowl earlier today while changing jets and thinking I'm needing a filter.
    Instead of just thinking about it, I think you've made a convincing argument to actually buy one and install it.

    On that note, I've gone 140->147.5 on the main jet and 40->35 on the pilot jet.
    Bike feels nice and responsive at throttle and I managed to lower my idle a lot too without stalling when warm. No more does my RPM shoot up when the carb is low on gas (After I always forget to turn the petcock to on).
    All that remains is to see how it'll do cold starts on the smaller pilot jet.
  9. Snypr18

    Snypr18 Adventurer

    Joined:
    Jun 30, 2020
    Oddometer:
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    Location:
    Arizona
    From photos of the KLX650C tachometer, it looks like the redline is about 7500 rpm. Is that also the redline for the R motor?
  10. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

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    Good question!

    I believe it as at the engines are almost exactly the same.
    Snypr18 likes this.
  11. Snypr18

    Snypr18 Adventurer

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    Thats kinda what I was thinking. I hooked up a Trailtech Vapor to my bike and it works pretty well. I was cruising around at about 65-70 mph the other day and could see what the RPM situation looked like for the first time, but realized I didnt know what the redline was for these bikes. I also discovered my idle speed is high by about 200 RPM.
  12. Tinter

    Tinter Adventurer

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    I'm having trouble with my oil level. I'm checking it fairly often now and since last changing the oil, I've gone no more than 500km total.
    I think my way of checking the oil might be flawed? I usually let it sit for a while on the side stand and then I tip it up so the bike stands level while I try to look at the glass (which is annoying by the way, as leveling the bike is best done standing up and reading the glass is best done crouching down).
    Using that method though, I found out I had overfilled it, so I siphoned some oil out so it the level was at the middle of the glass. I rode a few hundred km like that, it stayed pretty much in the middle, until I just yesterday rode about 120km home, to find that my oil level wasn't visible in the glass.
    I checked a few minutes after arriving home.
    Then I let it still for around 10 minutes, still gone.
    I took a short ride to fill gas, and checked when home, still gone.
    I added a bit of oil to see if I could see anything, but still gone.
    I let it sit for over an hour, still gone.
    I let it sit overnight, still gone.
    I tried to run it for about 30 seconds and then checking, while waiting, but nothing.
    I added even more oil and I got to see the level again.
    Then I run the engine for a bit again while waiting a few minutes for it to settle, but still gone.
    I think either I needed to wait a bit longer or I could shake it to redistribute the oil? But then I could then see the oil level near the bottom of the glass.
    I guess I was kind of expecting that the oil level would suddenly appear to be normal, but it never did.
    Which leads me to believe that the oil has disappeared? Or is it somehow hiding from me?
    The bike drips somewhat, but I'm pretty sure that is chain oil as it drips from the the front sprocket and it's thicker than I would expect from engine oil.
    It would however be weird if it managed to burn so much oil in just about 100km, that it the oil level would disappear from the glass. Especially since it's these 100 last km, but nothing weird about the 300-400 before that.
    Am I doing something wrong or is there something very wrong with my engine?
  13. markk53

    markk53 jack of all trades... Super Supporter

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    My 650 blew off oil when run on the road at more constant higher rpm. It also used more when I had the stock breather set up on it. The breather runs down to the air filter, so any condensed oil in the hose will end up in the air box and drip out on the ground.

    I made a PVC tube with some stainless scrub pad steel in it to condense some of the oil. It was up at the front of the frame above the cam cover, tilted to be down hill to the engine so the condensed oil might run back. Then I ran the hose to the air box. No more drippage. Still blew off oil, but better.

    The tube was simple, a 3-4" piece of 3/4" or 1" pvc (I forget which) filled with stainless steel scrub pad and two end caps glued on, then two holes drilled to fit pvc water supply line of the correct OD to fit the breather hose (aka - I forget the size), glue in two stubs of the smaller pvc. I heated and flared the ends of the small tube to better grip the hose when clamped on. The trick is to drill the fitting holes in a position to have the tube angled down at the engine end so any oil may run back into the engine. Sorry, no pictures at this moment, but I'll shoot some soon.

    Others would wrap a breather hose doing the same thing, a fair amount of it going down hill to the head.

    Attached Files:

  14. Tinter

    Tinter Adventurer

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    I might consider doing that, I should also look in the airbox to see if there's any oil.
    What stupefies me though is that I did a mix of highway and country road for an hour long drive down, then I did the same thing on the way back up, but it was only after the trip back up where I could see missing oil. If it did actually burn oil then it would've been at least 100ml in that ride back up.
  15. Snypr18

    Snypr18 Adventurer

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    I always check my oil when the motor is cold, usually in the morning before starting it. I crouch down to the sight-glass, pull the bike towards me with the front wheel straight, and check the oil level when the bike is as balanced upright as it can be; just barely leaning against my hands.
  16. Myway

    Myway Long timer

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    Jan 2, 2007
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    8,097
    Location:
    Knobby country
    Checking oil after a ride is the best.
    Keep the motor straight, let it idle for a few minutes, stop and then check the glass.
  17. Snypr18

    Snypr18 Adventurer

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    Did a bit of highway cruising last night for the first time in a looong time. First time with the Trailtech setup. I hit 6000 rpm right about 73mph. The bike starts getting a bit "light" much faster than that, so I am reasonably satisfied with it as is. Im curious though, what kind of rpm / speed ratios are you guys getting? Anyone re-gear for lower rpm on the freeway? I hesitate to re-gear, because I do quite enjoy how torquey the bike currently is. But it would also be nice to cruise longer distances without wringing the motor out.

    Right before I exited the freeway, the motor was bogging out on me a bit like it wasnt getting enough gas or something. Ran fine the rest of the way home. My highway jaunt was pretty short and I only used my turn signal once, right before the weird motor issues. Since I am not running a battery (650R), is it possible that running the signal somehow interfered with the current required for getting proper spark? First time I experienced this issue, a bit concerning.
  18. Lesharoturbo

    Lesharoturbo Nerdly Adventurer

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    Mar 23, 2009
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    Checked yesterday afternoon. 55mph indicated is just a tick over 4k on my stock gearing for the C model. I would expect 6k to be just over 80mph. Next time I will ride faster to confirm.
    Snypr18 likes this.
  19. InTooDeep

    InTooDeep Adventurer

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    Jan 30, 2012
    Oddometer:
    46
    Location:
    Sacramento CA
    I carry two counter sprockets one tooth different 1 for getting there then switch to the lower geared 1 for the dirt. Only takes a couple minutes to swap them out
    Snypr18 likes this.
  20. Snypr18

    Snypr18 Adventurer

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    Jun 30, 2020
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    Mine is currently on the factory 14/49 ratio, what ratio do you run on the road? Any idea what your rpm vs speed is? I am considering swapping over to maybe 14/47 or similar. If I could drop my highway rpm by about 500 it would be nice.