AMC RULES 37,130 #13976 Posted December 18, 2021 On 12/15/2021 at 4:14 AM, lynnmor said: There is no way that I would release the clamping without the two halves bolted together. If the halves spring open even a little, the sealant will no longer work. I drill thru both halves and use stainless steel screws, washers and locknuts. Tapping the aluminum may be OK, but that cast metal isn't as strong as bolting thru. So everyone knows, those "rivets" are simply protrusions from the one half, not a separate fastener. Drilled out the rivets, tapped the holes, blue Loc-tite on them threads, and then backed up with a nut. 3 Share this post Link to post Share on other sites
19richie66 17,508 #13977 Posted December 18, 2021 That’s going nowhere. Share this post Link to post Share on other sites
AMC RULES 37,130 #13978 Posted December 18, 2021 5 minutes ago, 19richie66 said: That’s going nowhere. Wasn't before all the overkill either. 2 Share this post Link to post Share on other sites
lynnmor 7,307 #13979 Posted December 18, 2021 24 minutes ago, AMC RULES said: Wasn't before all the overkill either. The thing is that the manifold is bolted down at the far ends and any stresses from that might tend to warp the castings a small amount. The carburetor bolts will squeeze the halves together but any movement in the mating surfaces will tend to break the seal. Yes, that sealing compound that was used will compensate for a tiny amount of that movement, but I would rather prevent it from the beginning. For those that never split the manifold, know that they are not precision machined anywhere. Anyway, your work is a vast improvement over stock. 2 Share this post Link to post Share on other sites
AMC RULES 37,130 #13980 Posted December 18, 2021 (edited) I have read here so many times about the gasket failing on these Onan intake manifolds leaking but I can tell you, it was no easy task to seperate the two halfs of this one. Highly doubt it ever had any sealing issue, and I believe it was only needing it's carb cleaned. It's crazy too, by just the addition of this little bit of attaching hardware, the thing seems to weigh twice as much. Edited December 18, 2021 by AMC RULES 1 Share this post Link to post Share on other sites
Handy Don 12,235 #13981 Posted December 18, 2021 @lynnmor suggested testing mine before thinking of disassembly. It passed so I left it alone except for gentle cleaning. My problem turned out to be a missing Welch plug on the carb. 1 Share this post Link to post Share on other sites
kpinnc 12,083 #13982 Posted December 18, 2021 18 minutes ago, AMC RULES said: Highly doubt it ever had any sealing issue, and I believe it was only needing it's carb cleaned. Sealing the manifold on my P220 absolutely fixed the issues I had been having. My 520-H required full choke to run without surging. Cleaning the carb made no difference whatsoever. I didn't split the manifold, but rather ran a bead of silicone around the seam. Now (two years since) my tractor runs smooth as a top and choke is only needed for cold starts. 3 Share this post Link to post Share on other sites
Horse Newbie 7,074 #13983 Posted December 18, 2021 2 hours ago, kpinnc said: I didn't split the manifold I did not split mine on my 1994 520H either. I resealed the seam with something made for exposure to gas… forgot the name of it, but it’s in one of my threads. My problem was probably where the exhaust heat shield had rubbed a hole. 2 Share this post Link to post Share on other sites
Gregor 4,846 #13984 Posted December 18, 2021 I swapped out the lug bolts on the 656 for lug nuts. I think I may have all the tractors done now. 7 3 Share this post Link to post Share on other sites
Horse Newbie 7,074 #13985 Posted December 18, 2021 I had to move my 1994 520H to get another tractor out of the shed… do you guys hear a knock in the 20 hp Onan ? IMG_0154.MOV 3 Share this post Link to post Share on other sites
Gregor 4,846 #13986 Posted December 18, 2021 Time to get your stethoscope out. Try to narrow it down. 2 Share this post Link to post Share on other sites
kpinnc 12,083 #13987 Posted December 18, 2021 (edited) 1 hour ago, Horse Newbie said: I had to move my 1994 520H to get another tractor out of the shed… do you guys hear a knock in the 20 hp Onan ? Good first thing to look at would be to pull the heads and decarbon them. If carbon buildup gets heavy enough between the head and valves, the valves can't fully extend open. Can definitely make the cam and lifters knock a bit. Edited December 18, 2021 by kpinnc 1 Share this post Link to post Share on other sites
lynnmor 7,307 #13988 Posted December 18, 2021 4 minutes ago, kpinnc said: Good first thing to look at would be to pull the heads and decarbon them. If carbon buildup gets heavy enough between the head and valves, the valves can't fully extend open. Can definitely make the cam and lifters knock a bit. To add to the above, I always do a compression test when engine problems are suspected. While the heads are off you can see if there is play in the rod bearings by rocking the crankshaft back and forth to see if the pistons move immediately when reversing direction. Also, check the valve seats for looseness. 2 Share this post Link to post Share on other sites
SylvanLakeWH 25,598 #13989 Posted December 18, 2021 Wheel bearing failure front left tire while plowing snow… errrrggghhh…! Finished with back up plow and then replaced bearings with old spare set… Lucky the tractor was 25’ from garage… wheel came off as I got it in garage pushing slowly with me foot holding the tire on… Both bearings failed same way. Design / manufacturing flaw? 4 Share this post Link to post Share on other sites
ranger 1,750 #13990 Posted December 18, 2021 15 minutes ago, lynnmor said: To add to the above, I always do a compression test when engine problems are suspected. While the heads are off you can see if there is play in the rod bearings by rocking the crankshaft back and forth to see if the pistons move immediately when reversing direction. Also, check the valve seats for looseness. Compression tests are always a good idea when diagnosing engine issues, and before pulling things apart. One thing though, when checking for play in con rod bearings, position the piston halfway down the bore, not at T.D.C, or B.D.C. Or you will see quite a bit of crank movement before the piston moves, as the big end swings through top or bottom dead centres, which can lead to confusion! Doug. 1 Share this post Link to post Share on other sites
lynnmor 7,307 #13991 Posted December 18, 2021 1 hour ago, ranger said: Compression tests are always a good idea when diagnosing engine issues, and before pulling things apart. One thing though, when checking for play in con rod bearings, position the piston halfway down the bore, not at T.D.C, or B.D.C. Or you will see quite a bit of crank movement before the piston moves, as the big end swings through top or bottom dead centres, which can lead to confusion! Doug. That's true, I should have added that. 1 Share this post Link to post Share on other sites
ebinmaine 67,593 #13992 Posted December 19, 2021 9 hours ago, Gregor said: I swapped out the lug bolts on the 656 for lug nuts. I think I may have all the tractors done now. Snazzy. We have lug nuts and studs on all our tractors. Soooo much easier when swapping wheels or even just the first and only time they'll be mounted. 2 Share this post Link to post Share on other sites
ebinmaine 67,593 #13993 Posted December 19, 2021 Spent all day working on the '75 C160 Automatic. Quite a few things done. Fluid filled tires and spacers. Steel weights. Chains on. Got the plow hitch modified for an automatic and installed. Plow is painted up. More pics & video tomorrow. We're getting a decent snowfall tonight. 5 13 Share this post Link to post Share on other sites
Snoopy11 5,714 #13994 Posted December 19, 2021 8 minutes ago, ebinmaine said: Plow is painted up That's not a 4 foot blade, is it? You aren't much taller than it... Don 1 2 Share this post Link to post Share on other sites
Snoopy11 5,714 #13995 Posted December 19, 2021 By the way @ebinmaine... that Horse there is so beautiful. That color is, just perfect. The gloss is like a mirror! Don 3 Share this post Link to post Share on other sites
Thor27 769 #13996 Posted December 19, 2021 6' blade? 2 Share this post Link to post Share on other sites
Snoopy11 5,714 #13997 Posted December 19, 2021 Just now, Thor27 said: 6' blade? No, gotta be 5' His head is 1' in itself... Don 2 Share this post Link to post Share on other sites
Thor27 769 #13998 Posted December 19, 2021 Just now, Snoopy11 said: No, gotta be 5' His head is 1' in itself... Don Kinda figured he was like 8 feet tall 2 Share this post Link to post Share on other sites
Thor27 769 #13999 Posted December 19, 2021 And that 160 really looks good Eric! 1 1 Share this post Link to post Share on other sites
oliver2-44 9,759 #14000 Posted December 19, 2021 1 hour ago, ebinmaine said: Got the plow hitch modified for an automatic I wasn’t aware any mods were required 8speed vs automatic. What did you have to do to it? 1 hour ago, ebinmaine said: Share this post Link to post Share on other sites