Posted July 25, 2002 - 09:56 PM
It was making like a knocking sound, but the top and bottom end bearings are tight. I noticed that when i push the piston hard up agains the cylinder, it makes the culprit noise... but that's where i got the .0045 measurement from, so its not hitting the cylinder.
Also, the cylinder is perfect, no scratches or scuffs or anything. Could the noise just be normal engine noise?
Any help is appreciated, thanks!
[ July 25, 2002: Message edited by: acarter920 ]
Posted July 25, 2002 - 10:15 AM
It could be normal noise, I have no experience with that motor so I don't have any idea what noises it makes.
Posted July 25, 2002 - 11:45 AM
if you checked it right(like sirthumpalot said), I think that is too much
best thing to do is call a Susuki Dealer or Piston Dealer (wiseco etc.)
I would GUESS .0025 to .003 inches
Posted July 25, 2002 - 12:14 PM
Because as the ring wears, the clearance would be less when the piston is pushed all the way to one side. Did i just confuse myself?.. or did i confuse everyone else also?
Lol, I think my best bet would be to call a zuki dealer. I never even thought of that.
Posted July 25, 2002 - 01:32 PM
Posted July 25, 2002 - 01:36 PM
Posted July 25, 2002 - 03:34 PM
Posted July 25, 2002 - 05:48 PM
The bike is an 00' and it sound like the piston is slapping. But there are no wear marks on the piston or cylinder whatsoever. This is what has me puzzled. It could very well just be normal engine noise.
Maybe i just need to ride it and forget about it... thanks for the help
Posted July 25, 2002 - 05:51 PM
I ask because i already have everything back together and dont feel like tearing it apart again.
Posted July 26, 2002 - 01:17 AM
The piston skirt will wear, and eventually be too small in diameter to be within the service spec and should be replaced. But generally speaking, the ring wear and piston to wall clearance are unrelated.
Did that make sense or did I just confuse you more (along with myself!)?
Posted July 26, 2002 - 02:42 AM
Posted July 26, 2002 - 02:46 AM
Most 2 strokes require .002" (two thousands)
clearance between cyclinder and piston to prevent seizing. If you have more than that a small rattling noise will develop. Then the noise will accelerate due the excess movement inside the cylinder. Eventually the skirt will stress fracture and break off. Then your motor will either seize or worse grind it up and you will need to split cases to clean that crap out.
My advice is for you to take the cylinder off and get the exact bore measurement to the .0000" Then buy the piston accordingly.
This is speaking from experience
Posted July 26, 2002 - 05:16 PM
.0045 should be fine. RM make noise new or old. When i did the top end on mine it made the same knock that it did with the old piston.
The only RM that didnt rattle, was a 96 i saw that had a PC motor in it. Very smooth sounding.
Posted July 26, 2002 - 05:23 PM
Posted July 27, 2002 - 04:44 AM
Blatham, you are right, .045" clearance would be a little much, lol. I meant to put .0045" but forgot to put in the extra zero
I went to a local bike shop, and they said the Rm's are real noisy, so I think everything is fine and dandy. Thanks for the peace of mind everyone!
Posted July 28, 2002 - 10:54 AM
Ring gap and Piston to cylinder clearance are 2
When the rings rub up and down against the cylinder they wear. as they wear they open up more thus more end gap. too much end gap low compression.
As the piston rubs up and down against the cylinder it wears and becomes smaller thus more clearance between the cylinder and piston.
Too much piston clearance and the piston slaps against the cylinder thus breaks the piston skirt off. When the skirt breaks off the parts lock up the motor. You dont want this to happen.
Posted July 30, 2002 - 09:08 PM
As I said before the prob is that it will not rev cleanly under power( revs fine in nuetral), and it just WILL NOT come onto the pipe.
If anyone has any ideas, thanks in advance, if not, sorry for wasting space on 2 smoke probs...hehe
Posted July 31, 2002 - 07:40 AM
It sounds like a spark problem. Try a new plug. Check the gap. If its too big it could cause a situation like that. You can gap it as low as .020. The gap could be too small too. I forgot what the manual reccomends but .024-.028 is usually about right for most 2-strokes.
You can check the spark too. Take the plug out and put it back into the boot. Ground the electrode to a head nut. Kick the motor over and look at the spark. It should be large and blue. If its yellow or small its a sign that there is a problem somewhere in the electrical system.
Check all the electrical connections and grounds. Make sure they are clean and tight. Wraping them in electrical tape will keep water and other crud out.
If that dosent work it pull the magneto cover off. If there is junk inside or water got in the stator coils could have been damaged.
Wait i forgot one. Pull the plug boot off and check the wire going into it. There should be about a 1/4 inch of bare wire. If not trim the sheilding back a little.
Posted July 31, 2002 - 07:50 AM
Do your spark check and all, but my money is a reed that isnt up to par.
Twostroke guys should automatically do the reed when the cylinder comes off. They're usually only 15 bucks. Cheap insurance. Id go around the whole thing and make sure you didnt do something silly too. My buddy put the piston in his CR500 backward. It happens. It ran, but wouldnt pull second gear.
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