Author Topic: Shot Motor at 7k miles, Are These Interference Engines?  (Read 829 times)

HogDogger

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Shot Motor at 7k miles, Are These Interference Engines?
« on: Aug 31, 2020, 09:43:20 am »
I was out riding yesterday pushing pretty hard riding with sportier bikes and my motor gave out.  Hard to replay in my mind exactly what I heard and felt at the time of failure but after sustained high RPM the motor just quit.  No engine warning light.  I haven't gone through the diagnostic menu yet but I'm not sure the computer knows there's a problem. 

After quite a few tries the motor did start again but I shut it down pretty fast as there is a bad sound.  My friends are saying from the rear cylinder.  It's not a heavy duty clunking sound but more of a hard to put your finger on but obvious bad metallic sound. 

I think I've damaged the valve train.  Collapsed lifer, bent pushrod, bent valve, broken valve spring.. something along those lines is my guess right now.  I'm thinking one or more valves isn't operating properly and thus the hard as hell starting. 

If I dropped a valve would the piston have beat it up? 

I will start tearing things down tonight.

I'm open to all input.  Thank you. 

Stock motor with Ivan's ECU, pipes, filter, and always fresh oil. 
« Last Edit: Aug 31, 2020, 11:24:19 am by HogDogger »

RoadStarRaider

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    Fiddles

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    Re: Shot Motor at 7k miles, Are These Interference Engines?
    « Reply #1 on: Aug 31, 2020, 11:39:14 am »
    Check your front drive pulley  they have been known to come loose and makes a ugly noise, just a thought
    V&H 2into1, Bullet cowl, Full Wrap front Fender, Ultimate  seat, Barons Tach, lowering bones and progressive spring, Ivan's flash, K&N filter with open air box, Avon Cobra Chrome  tires

    A.T.

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    Re: Shot Motor at 7k miles, Are These Interference Engines?
    « Reply #2 on: Aug 31, 2020, 02:58:38 pm »
    The initial 08s and 09s had lifter issues...my 08 bike had them replaced twice

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      HogDogger

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #3 on: Aug 31, 2020, 04:08:32 pm »
      If the front drive pulley came loose I can't see that causing the motor to just stop running and then make the bike very hard to restart.  The symptoms don't seem to align with that.

      I think it was a lifter.  My bike is an 09 so it does fall in that range.  I had read about the bad lifters but I never saw anybody have a total failure rather they just started making noise.  If the lifer quit lifting or got stuck at the top then it's going to be a question of what damage happened downed stream.




      sundancer87

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #4 on: Aug 31, 2020, 04:48:20 pm »
      The first thing, before tearing into the engine would be to do a compression check.  If there is a valve problem it'll show up there.
      If the engine dropped a valve the resulting damage is usually the valve head gets pounded into the top of the piston and normally prevents the engine from turning over because the valve head doesn't belong between the top of the piston and the cylinder head.
      Additionally, if the valve head gets pushed through the piston and ends up in the bottom of the engine you'll have major problems.
      Do the compression check and see where you are before going too far.

      HogDogger

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #5 on: Aug 31, 2020, 05:21:10 pm »
      So it IS an interference engine?


      the urban legend

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #6 on: Aug 31, 2020, 06:33:30 pm »
      So it IS an interference engine?

      Even if it isn't, if a valve falls inside the cylinder it will automatically become one. 

      A compression test might be hard to do since these engines have a built in mechanical decompressor. A cylinder leak down test would probably be more accurate.
      If you have an inspection camera, I would start by having a look inside both cylinders to see if anything looks odd before going further. Just removing the spark plugs could give you a clue. If something broke inside the cylinder, it will likely have beaten the end of the plugs to death.
      I'd rather die on a motorcycle than live without one.

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      sundancer87

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #7 on: Aug 31, 2020, 06:38:20 pm »
      Unless someone knows for sure the only way to tell is to pull the head(s) and look. 
      http://knowhow.napaonline.com/what-is-a-non-interference-engine/

      HogDogger

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #8 on: Sep 01, 2020, 08:21:40 pm »
      I'm about to start working on it. 

      I don't think I have a valve broken off (oh please) maybe just one or more that aren't operating properly.  I can't imagine the engine starting if one cylinder was destroyed and out of the picture and the sound from that would be horrendous. 

      I agree a compression check looks complicated by the decompressor, there's no procedure for it in the manual either. 

      Who is the resident engine guy on this forum?  Can the heads come off with the engine in the bike?

      Phalcun

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #9 on: Sep 12, 2020, 12:02:29 pm »
      Head isn't too bad but rear cylinder is a little tricky to pull off cause you got limited room and gotta twist , just be extra careful, front head is easy to pull, if you got the head off your'e gonna want to replace lower cylinder gasket.  You thought to borrow a borescope to check internals first? You may find issue with just the rockerbox cover off, its not much fun to pull either.

      HogDogger

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #10 on: Sep 13, 2020, 01:40:34 pm »
      Thanks for the help guys.

      This ended up being a catastrophic engine failure.  The big end rod bearing is non existent.  There is literally about inch of play. 

      I bought this bike with 3k miles on it and it looked brand new and had no signs of abuse.  The first thing I did was change the oil and filter with the prescribed 5.2 quarts of oil.

      The failure happened at 7k miles.  When I went to drain the oil I got less than a quart out.  This obviously explains my bearing failure. 

      The bike burned over 4 quarts of oil in 3k miles.  I admittedly hadn't checked the level since I changed it, I'm just not really in the habit of that on motos, I just change it on time every time. 

      I'm really frustrated and will be reaching out to Yamaha for some help.  The project is on the shelf right now while I calm down and decide how to proceed.  I haven't found the reason for the oil consumption yet but there are only two ways that I know of an engine burns oil.  Oil gets past the rings from the bottom or oil gets past the valve seals from the top.   

      I'm hoping once I have the front cylinder apart it will be obvious where the problem is based on comparing carbon build up. 

      4 quarts in 3k miles yet my riding buds say they haven't noticed any excessive smoke...   The bike doesn't leak anything though so it could have only gone one place.. 

      Am I certain I put all the oil in when I did my change?   Yes, 100%.  The unique oil change method of filling the reservoir then running the engine then filling the rest is still very clear in my mind.


      Coldfinger

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #11 on: Sep 14, 2020, 10:08:43 am »
      Burning 4 quarts of oil in 3000 miles is crazy.   No leakage past one of the three oil drain plugs?

      Bike ran fine prior to the day the engine failed?

      Notice any blue smoke from the exhaust?
      « Last Edit: Sep 14, 2020, 10:11:55 am by Coldfinger »

      Dudeman

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #12 on: Sep 14, 2020, 10:24:18 am »
      That works out to 80:1 ratio. Some 2 strokes run on that.
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      sundancer87

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #13 on: Sep 14, 2020, 01:45:25 pm »
      I'm about to start working on it. 

      I don't think I have a valve broken off (oh please) maybe just one or more that aren't operating properly.  I can't imagine the engine starting if one cylinder was destroyed and out of the picture and the sound from that would be horrendous. 

      I agree a compression check looks complicated by the decompressor, there's no procedure for it in the manual either. 

      Who is the resident engine guy on this forum?  Can the heads come off with the engine in the bike?

      An engine with a compression release can have a compression test performed on it.  Albeit the compression will be low, as long as it is more or less equal.  The engine will have to be spun in reverse of the normal travel.

      StrykerBilly

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      Re: Shot Motor at 7k miles, Are These Interference Engines?
      « Reply #14 on: Sep 15, 2020, 07:57:01 am »
      Doesn't the Raider have a low oil warning light?  My Stryker does and it would have easily triggered well before being being 3 quarts low(unless there was an immediate/catastrophic loss...)