blown motor help! diagnosis?

Started by speedy619, December 02, 2003, 08:05:23 AM

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speedy619

 ???OK, I know its tough, but can you tell what the trouble is from a description of sound?  If anyone knows what common failures are with the early SV650; what are they.  My bike is stock.  Performance wise I have a Akropovick pipe, K & N filter and factory jet kit.  I bought it with 3000 miles and it has almost 1 season of racing on it.  I have barely maintained it with 4 oil changes over 12 race weekends.        :o Here's the bad news, first race Sunday morning I do one lap hit the rev limiter (like I have a few.... umm times) and hear this hideous noise.  The bike still starts and runs, but it sounds like a low rough rumble and nothing at idle.  As soon as I rev it above 2-3000 rpm it starts to grumble.  It kinda sounds like a diesel noise, but muffled.  I have looked down the spark plug hole, checked the plugs, looked into the intake track and nothing.  I even pressed the top of the pistons to check play of the rods on the crank.  I can't tell anything from this quick check.     Any suggestions?  I will be grateful!!  ::)

Mark Bernard

Quote???OK, I know its tough, but can you tell what the trouble is from a description of sound?  If anyone knows what common failures are with the early SV650; what are they.  My bike is stock.  Performance wise I have a Akropovick pipe, K & N filter and factory jet kit.  I bought it with 3000 miles and it has almost 1 season of racing on it.  I have barely maintained it with 4 oil changes over 12 race weekends.        :o Here's the bad news, first race Sunday morning I do one lap hit the rev limiter (like I have a few.... umm times) and hear this hideous noise.  The bike still starts and runs, but it sounds like a low rough rumble and nothing at idle.  As soon as I rev it above 2-3000 rpm it starts to grumble.  It kinda sounds like a diesel noise, but muffled.  I have looked down the spark plug hole, checked the plugs, looked into the intake track and nothing.  I even pressed the top of the pistons to check play of the rods on the crank.  I can't tell anything from this quick check.     Any suggestions?  I will be grateful!!  ::)
un fortunatly ... your going to have to tear it down. At least pull the heads and jugs and then check your rod play. Go from there. Good luck!
Mark (Bernie) Bernard
Race Control CCS/ASRA - Mid-West Region

Nate R

Most common SV problems are rod bearings, and then I think cranks.
Nate Reik
MotoSliders, LLC
www.motosliders.com
Missing my SV :-(

Super Dave

Might be worth popping the side covers out to make sure the exterior components haven't loosened on the crank.  It happened to me once.  

Super Dave

mdr14

Matt Drucker
MD Racing
www.mdracingstp.com

speedy619

Thanks for all the info. guys.  I will be taking it apart this week and I will post the good/bad news. ???  Please pray for me! :D

Mark Bernard

Hominey hominey... domino nabisco... a-men!
There ya go!  ;)
Mark (Bernie) Bernard
Race Control CCS/ASRA - Mid-West Region

tzracer

QuoteHominey hominey... domino nabisco... a-men!
There ya go!  ;)

I'm not sure I want to know.
Brian McLaughlin
http://www.redflagfund.org
Donate at http://www.donate.redflagfund.org
 
2 strokes smoke, 4 strokes choke

Mark Bernard

QuoteI'm not sure I want to know.
Your right Brian... you dont want to know!!  :o ;)
Mark (Bernie) Bernard
Race Control CCS/ASRA - Mid-West Region

DAmico

i would check the cam chain tensioners. suz ones are shite.  wrist pins being galled make that noise also.

speedy619

OK, gang here is the latest news.  I pulled the motor and the front cylinder conrod bearings are shot and it looks like they spun.  The rear conrod bearings look OK.  I have not measured anything yet, just finished the disassembly.  The bike did run, but sounded very bad.  It has been a race bike for 11 race weekends and it had 3000 miles on it before that.  I seen no other unusual wear.  It does look like it was running rich and the oil level was low, but not out of range on the sight glass.  I have little money and want to get this thing running again any suggestions?  I am in need of help/guidance!  

Why not repair the crank?  I have quote of $300 for repairs if it is not badly scored.

Mike

Tunersricebowl

Forget repairing the crank,at least for racetrack use.
Also keep in mind that all the particles from the destroyed bearing have damaged the oil pump and probably everything else as well. low miles used engine is the best way to go.