ORIGINAL: SrTelemaster150
ORIGINAL: init4fun
To the Op I say ,
If your engine sounds like the 270 in the video , then it's got gear lash issues and if your not willing to adjust the gear lash , I'd send it back .
My 270 makes no such sound at all when running , all you can hear is the exhaust . Now , when I took mine apart to replace the bad bearings , the two cam/lifter holders had different amounts of thin gaskets under them , the left cyl had one and the right had three , if I recall correctly , and that obviously reflects the cam gear clearance having been set at the time of manufacture . I made darned sure to return the same number of gaskets(being used as spacers) to each cam holder , and have no whining noise .
What raises the red flags to me is the fact that he gets the ''notchy'' feeling every 180 degrees. If increasing the lash W/more gaskets relieves the tight lash at these 180 degree locations, then each cam gear is going to have excess lash for the remaining portions of the 360 degree rotation between tight spots. Also remember that the tight pinion fault will be occuring 2X in every rotation of the cam gear.
The symptoms points to a fault in the crankshaft pinion that would come under the opposing cam gears every 180 degrees. It's not likely that each cam gear has a fualt in exactly the same orientation.
While shimming the cam housings might treat the symptomes, it will not correct a serious defect in the crank pinion.
It would be interesting to know at what cycle stroke (EX/IN/compression/power) the notchy feeling occurs. A crank pinion fault could occur at any point in the cycle.
A very good point indeed ! ....... Yes , improper lash would be improper lash for the full rotation of the gear , and not at exactly every half turn . So this does leave the OP with a real operational problem with it , and I'm happy to see that the OP will send it back . I do notice , by looking at the parts identification for my 270 , that the cam drive gear on the crankshaft seems replaceable , but again , I'd let the seller worry about that .