Engine squealing noise
Posted October 29, 2001 - 08:16 AM
While woods riding this past weekend in southern Oregon, my '01 WR426 began making a squealing/screeching (bearing?)noise from the engine at 1/3 or greater throttle opening. Putting pressure on the clutch lever did not change the noise at all. The noise is audible in every gear and is definitely load related, not RPM or speed sensitive.
Oil is changed regularly with Castrol Actevo 10w/40 synthetic blend. Engine is unchanged except for YZ cam timing and revised jetting.
Thanks for your input.
Posted October 29, 2001 - 08:31 AM
Posted October 29, 2001 - 11:56 AM
Did you try the screwdriver at the ear stethoscope? It will help you to isolate the source of the noise.
Posted October 29, 2001 - 12:23 PM
For a closer visual you can :
Remove mag side cover as well as clutch side cover. You could even take it a step further and remove the magneto and then on clutch side the counterbalancer. This will alow you to check out the counterbalancer bearings and have a peek at your crank also. Good time to remove / inspect the clutch as well.
With the clutch cover off you will be able to ascertain the condition of the water pump bearing also.
Hopefully it's something on the exterior of the cases.
Good luck and work patiently!
Posted October 29, 2001 - 03:30 PM
I warmed the bike up and drained the oil into a clean pan and then strained the oil through a clean white cloth. All clean! The magnetic drain plug had no debris attached.
I checked the filter and found some flakes that look like aluminium. the quantity was less than is typical for a first oil change.
While warming the bike up, per SFO's suggestion, I tried the "Ear-o-scope" with a screwdriver but could not determine which side had the most noise amidst all the normal YZF clatter.
RE: dropped cam retainer - been there, done that (with my 99 WR 400) so I was very careful when I did the cam timing/valve adjust on this bike, over 500 miles ago.
Tomorrow I will wash the rest of the mud off the bike and take the clutch cover and side cases off and see what I can find.
Thanks for the input.
Posted November 01, 2001 - 05:39 PM
What I interpreted as a squealing bearing type engine noise was solved with a couple blows from a rubber mallet before I removed the side cases.
While contemplating my dilemna and examining the bike over a couple of cold Full Sail IPA's, I noticed a small amount of soot around one side of the rear lip of the silencer can / spark arrestor junction.
After one of my failed attempts at a long, steep, hillclimb last Saturday, I had drug the bike around on its right side to get it pointed downhill. This had slightly bent the endcap of the stock silencer and allowed just enough air leakage at large throttle openings to make a VERY loud whistling noise.
Thanks for the suggestions.
Posted November 02, 2001 - 03:54 AM
Glad you figured it out....