857lover 291 #1 Posted July 11, 2022 so i am finally getting around to putting my k181 back together and i noticed that it’s super hard to rotate the engine with everything installed the governor the piston and crank i can’t turn it by hand but if i put the crank nut on the eng i can spin it with a ratchet and i also noticed my exhuast valve is staying open like it has a little bit of movie t but it will never fully seat back down any ideas i thought it could have to do with the acr system not sure first engine rebuild i’ve ever. done Share this post Link to post Share on other sites
rmaynard 15,458 #2 Posted July 11, 2022 Did you do a complete rebuild? What was replaced? Rings? Rod? Cylinder bore? A little more info would ne helpful. Share this post Link to post Share on other sites
857lover 291 #3 Posted July 11, 2022 Just now, rmaynard said: Did you do a complete rebuild? What was replaced? Rings? Rod? Cylinder bore? A little more info would ne helpful. yes the cylinder was bored .10 over has new piston and rings they also took .10 off the crank so i have the rod to match and the bearings where changed the valves where changed Share this post Link to post Share on other sites
8ntruck 7,002 #4 Posted July 11, 2022 Did you use an assembly lube when you put it back together? 1 2 Share this post Link to post Share on other sites
squonk 41,104 #5 Posted July 11, 2022 Did you grind the valve stems to set clearance? 1 1 Share this post Link to post Share on other sites
rmaynard 15,458 #6 Posted July 11, 2022 (edited) As far as the exhaust valve problem, new valves almost always need to be adjusted. The K181 does not have adjusters and the stems of the valves have to be ground to be adjusted. If exhaust valve is not closing all the way, I don't suspect it is the ACR as it only opens the valve slightly during the compression cycle until the engine reaches 600 RPM. Edited July 11, 2022 by rmaynard 1 Share this post Link to post Share on other sites
rmaynard 15,458 #7 Posted July 11, 2022 Hopefully the rod and the crank are a match. I always use Plastigage to check the gap. 1 Share this post Link to post Share on other sites
Tuneup 1,433 #8 Posted July 11, 2022 If you are short a cup or more of coffee and put the rod cap on backwards, this happens. I know so, personally. 1 Share this post Link to post Share on other sites
857lover 291 #9 Posted July 11, 2022 1 minute ago, Tuneup said: If you are short a cup or more of coffee and put the rod cap on backwards, this happens. I know so, personally. i’m put a yellow paint line on to make sure but i’ll double check Share this post Link to post Share on other sites
857lover 291 #10 Posted July 11, 2022 4 hours ago, squonk said: Did you grind the valve stems to set clearance? no i have not messed with it how do you do that ?? Share this post Link to post Share on other sites
squonk 41,104 #11 Posted July 11, 2022 First is it even an ACR engine? Is the cam 1 piece or 2 piece? I suggest you read these threads and download the repair manual. Share this post Link to post Share on other sites
rmaynard 15,458 #12 Posted July 11, 2022 Check the valve clearance with a feeler gauge. If the gap is too tight or non-existent, the valve in question must be removed and the bottom of the stem carefully ground to achieve the proper gap. Usually done at a machine shop, or if you have the correct equipment you can do it yourself. It's a trial and error. 1 Share this post Link to post Share on other sites
Handy Don 12,217 #13 Posted July 11, 2022 1 hour ago, rmaynard said: It's a trial and error Or, more hopefully, a trial and success! 2 Share this post Link to post Share on other sites
857lover 291 #14 Posted July 11, 2022 7 hours ago, rmaynard said: Check the valve clearance with a feeler gauge. If the gap is too tight or non-existent, the valve in question must be removed and the bottom of the stem carefully ground to achieve the proper gap. Usually done at a machine shop, or if you have the correct equipment you can do it yourself. It's a trial and error. i will have to clearance intake aswell too then Share this post Link to post Share on other sites
richmondred01 2,237 #15 Posted July 13, 2022 (edited) The valve stems must be ground on a valve stem/facing grinder. Don’t think that you can get a level cut on your bench grinder or using a file. Edited July 13, 2022 by richmondred01 3 Share this post Link to post Share on other sites
