Me again! Dumb question

Tue Dec 10, 2013 9:37 pm

Have looked all over w/no results - going to mic cylinders - at what point do I consider re-ringing or reboring?? Can't find any info on what is considered past the point of reasonable wear. Does not use excessive amount of oil, minimal smoke, had good power. By the way Boss, could not detect any cracks in the bolster, maybe I got lucky!!! (hope, hope!). Would just new rings be worth the time and effort to "refresh" the compression? W/be touching up the valves while it's open too. Thanks for the input! Dusty B

Re: Me again! Dumb question

Tue Dec 10, 2013 9:51 pm

My manual says that if the bore is .005" over the nominal bore size it requires reboring. I am not a fan of re-ringing unless the bore is well within specifications. Reason being the bores don't wear the same amount throughout the bore. If you adjust the ring gap in an area that has more wear then other areas of the bore, you stand a chance of binding the rings possibly causing a catastrophic failure. Others here will disagree with my opinion, maybe most. This page from the manual differs from mine but should help you decide if re-ringing is an acceptable route to go.

Image

Re: Me again! Dumb question

Wed Dec 11, 2013 9:24 am

Thanks Ricky - that was what I was looking for -could not find it anywhere??! Dusty B

Re: Me again! Dumb question

Wed Dec 11, 2013 9:30 pm

Good news/bad news! Good news - cylinders all OK - no egg shape - w/in specs! Bad news -did find the hairline crack along the lip of the bolster (spot on Boss!) going to ream it out and give it the JB Weld try. No apparent problems anywhere else. Also w/be able to use the head off Katrina. Sooo - touch up valves & adjust, reassemble and ready? to mow next spring!!!

Re: Me again! Dumb question

Wed Dec 11, 2013 9:44 pm

It sure would be nice to pressure test the block to make sure you don't have any other surprises after all the work and expense sprucing up the motor. It would be a bad time to find out there are other cracks somewhere else. If you can put the head on, remove the spark plugs and pressurize the system and see if it bleeds down, it might save you a lot of time and expense. How to pressurize the system. Image Those smarter than me will be along.

Re: Me again! Dumb question

Thu Dec 12, 2013 12:39 pm

Dusty!!---Ricky has ya covered!---I too would go the total re-build route IF you plan on actually pulling the motor very hard or very long at the time getting it hot, etc.---The new rings, IF they will ever seat on the old bores and up the compression, will add more pressure on the rod/main bearings too, so be sure to check the condition of them as well!---At least do a quick hone job on the cylinder walls!---a couple passes will tell you a lot as to the bore shape and at that point you can decide which way to go at that time! thanks; sonny

Re: Me again! Dumb question

Tue Dec 17, 2013 1:07 pm

Personally, if I had the engine down far enough to mic the bores, I would also check the crank & big ends & replace the bearings as well.