AlexR 2,286 #1 Posted Saturday at 09:55 PM (edited) So I went over to my neighbors today (because he has a cylinder bore gauge and micrometers) to check out the spare engine I have that I thought was a 12hp K301 because of the tins. So the bore gauge you set to the spec you are aiming for with a micrometer so I set it to the max wear limit for the K301 3.378 well it was too small for the bore by a lot well I measure the bore and it's about 3.5 it's a K321 block. So I set it for the max wear limit on that 3.503 and it's all within spec on out of round and taper and within the wear limit. So it will just need honed. I was feeling pretty good and starting measuring the crank. And that was bad, I am kinda curious if you guys have seen numbers this bad. X axis Y axis 1.4871 1.4880 1.4869 1.4888 1.4869 1.4889 It's crazy that the taper is within spec at .0009 but the out of round is .002 the limit on that is .0005 and yes I double and triple checked you can actually see the gap going from the Y axis to the X It's also worn beyond the wear limit of 1.4990 Edited Saturday at 10:05 PM by AlexR 3 Share this post Link to post Share on other sites
markseven 66 #2 Posted Saturday at 10:17 PM My crankshaft was bad I think The measurement was 1.487 . I was going to get it machined and go .020 under but luckily found a used one that measured 1.5001. 1 Share this post Link to post Share on other sites
Achto 30,091 #3 Posted Saturday at 11:29 PM 1 hour ago, AlexR said: I am kinda curious if you guys have seen numbers this bad. I have had engines with a good bore & a crank out of wack. Also had them the other way around. Explanation unknown. I would scuff the cylinder, have the crank turned down for an under sized rod & slap ' er together. 5 Share this post Link to post Share on other sites
ri702bill 10,453 #4 Posted yesterday at 12:00 AM ... Purchase the connecting rod first. That way the machine shop can turn the crank to match that bore for the proper clearance fit... All replacement parts have dimensional tolerances too... 2 Share this post Link to post Share on other sites
lynnmor 8,177 #5 Posted 22 hours ago (edited) 2 hours ago, Achto said: I have had engines with a good bore & a crank out of wack. Also had them the other way around. Explanation unknown. I think that it depends on how the previous owner abused the engine. Few or no oil changes and non functioning air filter are favorite ways to destroy an engine. Edited 22 hours ago by lynnmor 2 Share this post Link to post Share on other sites
ineedanother 1,796 #6 Posted 20 hours ago 2 hours ago, lynnmor said: I think that it depends on how the previous owner abused the engine. Few or no oil changes and non functioning air filter are favorite ways to destroy an engine. As does improper rpm adjustments for idle and high end IMO. I agree that maintenance is paramount though with splash lubricated engines. You just can't deny the importance of having good lubrication between moving metal parts. 2 Share this post Link to post Share on other sites
ri702bill 10,453 #7 Posted 14 hours ago 6 hours ago, ineedanother said: improper rpm adjustments for idle and high end IMO. Truth there. Excessive idling at too low an RPM or over revving shortens the engine life. But you gotta love that "putt-putt-putt" sound a K series makes at low idle with the ACR working! 1 Share this post Link to post Share on other sites
AlexR 2,286 #8 Posted 1 hour ago So another question what is the best place to get parts from right now. I am aware of lil red barn, any other recommendations or should I got with them? Share this post Link to post Share on other sites
Achto 30,091 #9 Posted 54 minutes ago 25 minutes ago, AlexR said: any other recommendations The Man's One Stop Shop on Ebay is another good choice. I have had very good luck with them. https://www.ebay.com/itm/380933610622 1 Share this post Link to post Share on other sites
