Sand Inside the Engine? XR600R

Discussion in 'Thumpers' started by cavalier35, Jan 14, 2013.

  1. cavalier35

    cavalier35 Been here awhile

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    Hello,

    Long time follower, but I haven't posted a lot on the forum. Thanks in advance for all the help.

    I'm the owner of an 1989 XR600R, which I dual sported for about four or five months back. I've ridden about 1,000 miles on the bike with the normal updates/upgrades (ie Ricky Stator 200w stator and XR's Only Choke Plate)

    This past weekend, I went for my first ride on the sand dunes in Florence, OR. The bike didn't skip the beat the entire day but ran into a problem literally a mile away from the car after 4-5 hours of riding. The bike suddenly died (not sure if I lugged down the engine or not) and wouldn't restart. I managed to get it bump started in third gear after being towed for 500 yards and rode back to the truck.

    Since then, I can't seem to get it to fire at all. I noticed some sand had managed to get past the edges of my air filter and was stuck to the outside of my choke plate inside the carb.

    Is it possible sand got into my engine and caused it to not run? What kind of damage would that do? I checked both jets in the carb and seem to be clear. I did notice the compression seems to be low (I don't have a compression tester). I can cycle the piston all the way through without using the compression release, which I never had been able to before.

    Is it possible the rings are worn and the lack of compression isn't allowing a good vacuum for the fuel to be drawn to the cylinder?

    Thank you and please let me know if there's any other information I can provide to help dissect the issue.
    #1
  2. elsalvadorklr

    elsalvadorklr southern xr rider

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    only one way to find out bud

    what the compression psi?

    if low then rering

    since you are 89 nicasil you can rering and "HONE" if not you have to replate. oevrsize or reline with a steel sleeve....

    cheers

    p.s its very likey you ingested sand, how much isnt clear yet... I once rode on the beach and river ends on the beach long enough to coat a new filter with enough sand to weigh on a scale...it was completely blocked, and I used grease on all the airbox and filter seal area.
    #2
  3. Walterxr650l

    Walterxr650l Long timer

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    Unfortunately, yes it is possible sand got into your motor and is causing it not to run. (So far I have been able to avoid personal experience with this, So this information is just what I have heard hanging around cycle shops.) What I understand is the sand will take the hard surface off of the valves and/or valve seats. The valves then go rapidly out of adjustment. Probably why it won't start. You can adjust the valves and it might run, but they will go out of adjustment quickly, and your right back where you are now. Probably is time to tear it apart and rebuild the top end.

    Walter
    #3
  4. cavalier35

    cavalier35 Been here awhile

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    I will have to barrow a compression gauge and get back to you with the PSI. Is it possible I'm simply due for a re-ring and hone job? The engine is still running the original rings from the factory.



    I did pull the tappet covers and all the valve clearances were okay, but I'll double check this week. Should I also check the stator to make sure it's sending a good spark? Although it's a new stator, I imagine the aftermarket stators can fail as well. Ideally, pulling the top end apart is the last resort.
    #4
  5. mcma111

    mcma111 Long timer

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    There is no coating on the XR valves or seats. Check the valve clearances. My guess is that they will be tight. You most likely ingested some sand and have damaged the valves along with the piston and rings let alone the cylinder. Pull it apart otherwise your just wasting your time.
    #5
  6. cavalier35

    cavalier35 Been here awhile

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    Any idea how much sand it would take to ruin the valves and piston?

    I also ran the bike a lot harder than usual due to riding on the sand. Is it possible the rings needed to be replaced and the sand riding was the straw that broke the camels back?
    #6
  7. jules083

    jules083 Long timer

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    Could have been a combination of heat and running it hard on a motor that was almost worn out. I had a friend I raced motocross with wear out the top end during a 5 lap moto. Sounds dumb, but the bike ran great when the race started and barely ran at the end. New piston and rings, bike ran fine again. It was a yz80 though, not really known for longevity.

    All typos and misspellings blamed on my phone.
    #7
  8. cavalier35

    cavalier35 Been here awhile

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    Is it possible to get new rings for an original piston? Or would it make more sense to do new piston and rings at the same time?
    #8
  9. jules083

    jules083 Long timer

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    I would plan on piston and rings. Considering the age of the bike though its hard to say what all you're going to get into. Have to tear into it and see. The cylinder may be getting worn at this point also.

    I have a xr250 that's waiting on a rebuild. My plan is to tear everything apart and hope for the best but plan on the worst. I'm not even ordering any parts until I at least know what kind of shape the cylinder walls are in.

    Valves are an unknown for me. I've never done anything but adjust them, so I can't give you advice there.

    All typos and misspellings blamed on my phone.
    #9
  10. mcma111

    mcma111 Long timer

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    There is no way to know the condition of the piston and cylinder until you pull it apart and have a machinist measure the parts. It only takes a bit of sand for it to do major damage.
    #10
  11. mcma111

    mcma111 Long timer

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    Should it turn out that your piston and cylinder are damaged I have a XR cylinder with a Wiseco 100mm piston available. A light hone and fresh set of rings and it's ready to go.
    #11
  12. Unstable Rider

    Unstable Rider Moto Fartografist

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    Had you modifed your airbox, or changed your filter system from stock?
    #12
  13. cavalier35

    cavalier35 Been here awhile

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    Thank you Steve. To be honest, I'm dreading diving into the engine because I don't have any real experience working inside an engine. I rebuilt the top end of my XR500 but it was a learning experience and have since sold the bike. I'm also concerned about putting more money into it because I got about 1,700 into right now ($950 for the bike and 750 in parts. ie lighting kit, wheel bearings, stator, etc.).

    I'm not sure of any local reputable machine shops in the Vancouver, WA area. Is this something I can figure myself or does it really come down to tools?

    Someone previously opened up the air box, but then decided to duct taped the extra holes closed. I think the sand was getting around the base of the filter where it meets with the air box.
    #13
  14. elsalvadorklr

    elsalvadorklr southern xr rider

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    guys you have to pay attention here...its not as easy to HONE a nicasil plated cylinder...I went through the same scenario on my 88.


    What you HAVE to do is measure the ring end gaps, and piston to cylinder clearnance, AND if the cylinder is scratched...

    since you cant BORE nicasil unless you want to replate you have either the option of rering and simple hone(very soft) OR replating with all new piston and rings etc...

    OR resleeving, new piston rings etc...

    the last option is what I did, it was cheaper than replating...

    like steve said you wont ever find out till you take her apart

    no question will be answered well enough for you here.:D
    #14
  15. cavalier35

    cavalier35 Been here awhile

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    Have you done any work on your valves? How does the bike run now you've re-sleeved, replaced the piston and rings?

    I'm guessing the timing chain could be replaced along with the guides and tensioner spring. This is just based on age and the fact it's all original.
    #15
  16. elsalvadorklr

    elsalvadorklr southern xr rider

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    my engine is a bit modded now...valves, guides, seals, springs all new...hrc clone cam, etc...

    again you have to check the condition of everything to say yes or no

    also the timimg chain can be measured in the sprocket itself if you cant line up tdc with the 3 lines on the sprocket you are stretched, change ifneeded

    cheers

    ps. steve has an xrl/xr rebuild engine thread that is the best for info and pics and how to. Im sure he can link it for you
    #16
  17. mcma111

    mcma111 Long timer

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    #17
  18. cavalier35

    cavalier35 Been here awhile

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    Hi Steve,

    Great thread! I've come across it a time or two while trouble shooting things over the past year. Do you have an hourly rate? Or would this be more of a lump price?
    #18
  19. Hurricane Bob

    Hurricane Bob Long timer

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    The sand would not go through the fuel jets, just be carried along the air flow into the intake manifold past the intake valve and into the combustion chamber.:bueller


    Ingesting sand is considered a death sentence for engines.:*sip*


    please post photos during disassembly. :lurk
    #19
  20. elsalvadorklr

    elsalvadorklr southern xr rider

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    if you do decide to have someone do the work for you, look no further!

    Steves tools speak for themselves, he has helped me and many others and is definitely the xr guy on here...

    cant say enough good about him! ajjajajaajajajjajaja


    :D
    #20