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View Full Version : new here, Hello all,and I Have a valve problem?!?!?!


bigabe82
09-28-2009, 12:15 PM
How's it going guys? I've been watching everyone Else's problems for a month or so and Yall guys(and girl) come up with some great solutions for 'em. I haven't stumbled across any quiet like mine though. I'll make this as short as possible.

Kohler command 15.5 hp(on a craftsman 917271011). Bought mower for $25 on a good deal. Guy got rid of it because it developed a major problem of course. Upon starting(or the attempt of) you would have to seriously play with the throttle/choke lever(throttle and choke are on same lever, all the way up for choke...but I know yall knew that). I'd have to fully choke it, throw it all the way down upon fist sign of ignition, bring it right back up within a half a second, then make sure it is dead perfect on 3/4 to 7/8 choke. Anymore, any less results in engine dying! No throttle whatsoever is allowed by engine. So I take it apart and check/completely clean: carb, throttle/choke cable and lever, spark plug,fuel filter, gas cap, valves, piston(visual inspection, still in case, on the piston) safety switches(just in case), fuel shutoff/anti-dieseling solenoid and flywheel key.
Well the flywheel key was sheared but that was from me trying to mess with starting it so much that it kept kicking back and spinning opposite the rotation of the normal rotation. So I replaced the key and sheared it again. I replaced it one more time and this one hasn't sheared yet. So now that's done, I have the head pulled and have had it pulled about 13 times(seriously)and put it back on and noticed that the rocker arms(non-adjustable valve type) are supposed to be screwed down all the way. Well, as I do this, the push rods and valves tighten up with like 1/4 of an inch of screw left to tighten. So as I tighten the rocker arm screws all the way down, it begins to compress the valves. I can even have the engine like 10 degrees past top dead center and this will happen. Doesn't matter, top dead center or not, the valves have a constant, and quiet large pressure on them. This has to be the original problem. Leaky or open valves seem to cause this condition all over this forum but what could make both of them constantly compress like that????? oh, while both valves are compressed, at least they still move like they should, exhaust opens more when it should and intake moves more when it should. Any help would be awesome and greatly appreciated!! Don't know what to do :cry: :hammerhead:

bigabe82
09-28-2009, 01:47 PM
(sorry, didn't add this and couldn't figure out how to edit)........and when I say they move like they should, I mean when I spin the flywheel, but that's on top of still having that pressure on 'em. and My Engine is a kohler cv15s or cv16s

VegetiveSteam
09-28-2009, 02:23 PM
Your engine has hydraulic lifters in it and since the rocker arms have been loosened the lifters have extended all the way out. Before you can tighten the rocker arms back down the lifters need to have all the oil bled out of them. The best way to do that is to remove them but that will require taking the head off again. If you're not in a big hurry tighten everything down and let it sit for a few days. They will eventually bleed down.

Restrorob
09-28-2009, 02:33 PM
Adding to VS's post, If you tried to start the engine right after tightening the rockers there is a good chance the valves hit the piston. This can cause bent valves and or push-rods.

bigabe82
09-28-2009, 02:44 PM
Thank yall so much for responding!!:clapping:ok, so, just letting it sit for two or three days, completely assembled, and they'll bleed themselves? that would be nice. And when it would run, it'd run and sound like it was popping alot, the whole time actually. What do yall think the original problem was? And the valves still seat properly and no scratches or pitts on the piston or valves. I guess the original problem must have been a sheared flywheel key. it sounded like thrown timing and thats what the keyway is, so I guess I answered that one.:dizzy:

bigabe82
09-28-2009, 07:05 PM
so that's def it huh?

Restrorob
09-28-2009, 07:38 PM
Well,

Once you get the lifters bled down so the valves operate properly, See how it runs. If you still have problems post back, I leave them sat overnight and haven't had any issues......

bigabe82
09-28-2009, 09:12 PM
10-4. I'll do that first thing in the morning and get back to you. I looked at the schematics and the hyd. lifters don't look so hard to remove. Flip over the engine and take off the oil pump. So once I do that, I'll be back beggin' for help. Thanks alot man. I really do appreciate it!!:drinkup:

bigabe82
09-28-2009, 10:41 PM
ok,I just went ahead and pulled the head again. What's that process on bleeding those bad boys??

Restrorob
09-28-2009, 11:01 PM
Stand them up and with a 1/4" socket on a nut driver push down on the center of the lifter where the push-rod rides, Oil will squeeze out the top and side holes. Once the top of the lifter stops moving it's empty enough to be re-installed.

You don't have to do anything with the oil pump in regards to bleeding the lifters down.

BTW,

Since you've had this head off sooo many times, Did you replace the head gasket each time ?

bigabe82
09-28-2009, 11:11 PM
well, noooooooooo I haven't. It's sole purpose in life is a redneck:usflag: racer. Soooooooo since i've had the head off sooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooooooooooooooooooo many times, I haven't even bothered with it, knowing what symptoms it would give, I was just planning on replacing it when I cleared up these symptoms. I know It's not wise and it's a risk but the gasket is the lead one and looks perfect, I've been reusing it :nono:. Now with the bleed info, I feel confident enough to grab up a gasket a git er on there.

bigabe82
09-30-2009, 09:51 PM
So I pulled off the head again, didn't replace the head gasket again,pulled the lifters(was easier than I thought). I took 'em apart and cleaned 'em with gas. Put 'em back together and they had so much more movement. So the valves aren't gettin' compressed like they were. Great! right? WRONG! I'm pretty much back to square 1, or a little worse. Carb is cleaned(for kicks), lifters bled, spark plug is new, keyway is new and still intact at this point and I've sea foamed and changed the oil, and changed the filter and STILL, This thing acts like the intake is the exhaust. I cant even get it to start now. Constantly just puffing air and gas mist into the air. It's like the valves are just opening at the wrong time or something??? Not sure at this point????

Restrorob
09-30-2009, 10:41 PM
What on earth possessed you to take the lifters apart and wash them in gas no less ?


I've sea foamed and changed the oil


What weight oil did you put in it ?

bigabe82
10-01-2009, 12:55 AM
I had stiles equipment here in fort walton give me a new kohler filter and some straight thirty weight oil. I put 3/4 of a can of seafoam in the old oil before draining so the crankcase would be coated with a small film of seafoam and the remainder that never comes out would be treated with seafoam because the old oil was old old old, and sludgy. Which leads me to my excuse of why I cleaned the lifters with gas:nono: They couldn't be bleed by my strength alone so I figured out how to get them out and dismanteled them. I checked the little valve inside of them, the sping, all little holes and the pushrod seat. There was, what looked like to me, sludgy oil. So I cleaned them in gas and totally wiped them down afterwards. I put them back in dry after they set for a while.

Restrorob
10-01-2009, 10:14 PM
Well...... You could start by printing the below out and take it to where you bought the oil and tell them you want the proper oil for your engine. Kohler specifies this weight oil for a reason.

Intake valve not closing is what the problem sounds like, Bent valve or lifter pumped up too solid with the heavier oil or possibly a bad lifter would be my guesses.

Mr V/S explained how to bleed the lifters down so there was no need in disassembly, Just hope no contaminates got inside and is causing it to bind up.


http://i107.photobucket.com/albums/m314/Restrorob/Kohler/KohlerOilRecommendations.jpg

bigabe82
10-01-2009, 10:37 PM
I tried to do it how he said but they wouldn't budge. Also, was I supposed to lube them up before re-installation? when I did pull the lifters, I couldn't even bleed them. I had to take 'em apart.If the valves are bent, Its a microscopic bend because they look straight. I think this things camshaft took a dive. I'm about to just pull the bottom just to see the condition of whats visible.

Restrorob
10-01-2009, 11:08 PM
I tried to do it how he said but they wouldn't budge. Left sitting over night or so they would have bled down on their own. Also, was I supposed to lube them up before re-installation? Just soak them in 10w30 oil for about a hour then install and bleed as noted.when I did pull the lifters, I couldn't even bleed them. I had to take 'em apart.If the valves are bent, Its a microscopic bend because they look straight. Did you remove the valves from the head ? I think this things camshaft took a dive. A camshaft wears down it doesn't wear larger to cause a valve to stay open, Especially with the use of hydraulic lifters. I'm about to just pull the bottom just to see the condition of whats visible.


.................

Sharpcut 1
10-01-2009, 11:24 PM
I think your cam lobe on exhaust side is wipedout. Someting you said about air just shooting out. Pull out the lifters and shine a light on the lobes while a buddy turns it over slowly with a wrench. See if there is still a popint to the lobe, or if it is round.

bigabe82
10-02-2009, 09:46 AM
It looks almost completely round. The only thing thats on there is This pin looking thing. It's the only thing thats making the exhaust valve open up. The pin looks like a keyway would, just round and there's nothing else that it's holding. I guess it just basically makes that much needed bump in the lobe?

VegetiveSteam
10-02-2009, 12:26 PM
If you do find a flat cam lobe please let us know. I have never seen a flat cam on a Command single cylinder. Nothing is impossible but that would be almost unheard of. On the oil weight issue. Personally I like to use 10w30 like we always have. Last year Kohler came out and said straight 30w is an acceptable substitute when the ambient temperature is ABOVE 50 degrees F. When running the engine BELOW an ambient temperature of 50F you should ONLY use 10w30 or 5w20 if under 32F. Right now I don't think oil is an issue. Before you put the lifters back in after you cleaned them could you depress them? You should have been able to set them on the bench and depress them with a push rod and they should then spring back. After cleaning them with gasoline putting a drop or two of oil inside them would have been good and coat the outside with a thin film but you don't want to pump them up again.

bigabe82
10-02-2009, 01:49 PM
Temperature around here will only reach 50 a total of 7 days through out the whole year. It stays pretty warm. So the oil shouldn't be a problem. And the lifters were fine. I didn't need anything but my own hands to compress them after cleaning. When they were cleaned and back assembled, I could easily press the internals and would hear the little valve working inside. Lifters are good. The cam lobe didn't have major damage but wear was evident. Maybe it wasn't flat, but it sure had a lot less of a lobe than intake, but I guess that's common?

Sharpcut 1
10-13-2009, 03:54 PM
It looks almost completely round. The only thing thats on there is This pin looking thing. It's the only thing thats making the exhaust valve open up. The pin looks like a keyway would, just round and there's nothing else that it's holding. I guess it just basically makes that much needed bump in the lobe?

Little pin thing is your compression release. Helps you to pull it over by just bumping the exhaust valve before firing. Your lobes should pretty much be the same. If it's round, it's wiped out.

Sharpcut 1
10-13-2009, 03:56 PM
If you do find a flat cam lobe please let us know. I have never seen a flat cam on a Command single cylinder. Nothing is impossible but that would be almost unheard of. On the oil weight issue. Personally I like to use 10w30 like we always have. Last year Kohler came out and said straight 30w is an acceptable substitute when the ambient temperature is ABOVE 50 degrees F. When running the engine BELOW an ambient temperature of 50F you should ONLY use 10w30 or 5w20 if under 32F. Right now I don't think oil is an issue. Before you put the lifters back in after you cleaned them could you depress them? You should have been able to set them on the bench and depress them with a push rod and they should then spring back. After cleaning them with gasoline putting a drop or two of oil inside them would have been good and coat the outside with a thin film but you don't want to pump them up again.

I've had 2 wiped out cams in the last 30 days, both on 15HP. First ones i've seen. I'll see if I still have pictures. I think the zink the goverment took out of the oil is staring to play havoc with our cams. JMO.