Vanguard stuck valves

[BLES]

18 hp Vanguard twin with stuck intake valves due to old gas. Is there any way to get them freed up without removing heads? This is in a machine where engine would need to be completely removed to do the job. I wondered if i could get them free enough to start? Then run a serious mixture of seafoam or something to clear them off? Is this wishful thinking? Just trying to help an old neighbor who only runs this machine an hour or two a year (hence the stale fuel). It ran for a few minutes this spring and then bent a push rod.
Thanks.
BLES

[KE4AVB]

I feel fro you on the pulling of the engine.

I just got through with a JD 652R where you have to pull the engine just to adjust the valves. The way they did the muffler you can't remove the rocker covers so the valves were never adjusted until I did them after #2 exhaust to out the head.

[38racing]

any chance of getting marvel mystery oil applied to soak down around valve stem? I've used it to unstick mildly seized push mower engines.

[bgsengine]

If you got valve cover off, you could try penetrating oil (Kroil, PB Blaster, etc) to let it soak a day or two down the valve stems (may be able to make a moat around the guides with silicone or something to keep it soaking, but it wouldnt hold very long) and with springs attached, put a soft piece of wood or aluminum on the stem where rockers run on the valve and tap it with a hammer (gently) and it may be enough to start the valves loosening and you can just repeat the penetrating oil plus hammer taps til you can push valves down by hand and springs bring em back up - may be enough to get er started... But for the amount of time you'd spend doing THAT, you could just pull the engine enough to pop the head off and fix it right to begin with.

[KE4AVB]

It would be nice to know what this engine is (model and spec) and what is on but I assuming a 350000 series.

Sounds like he working on one the CC shaft drive models. What everyone here is forgetting is that the intake valves will have valve stems seals which has to be removed to even get any penetrating oil on the valve stems. To me sounds like the intake valve stem may have rusted on top of things. Now I have been having some very result with Acetone and transmission mix. I also have some POR15 rust remover here that might work if it is rust.

And if it is a CC shaft drive then yes the engine has to come out as getting the engine shroud off is nearly impossible. I had remove one a couple years ago due mice damaged wiring. The customer tried tell me it only took 30 minutes to R&R the engine. Well it took over two hours getting it out and one hour getting it back in. But only took 30 minutes to rewire it. And an engine lift is very helpful when you are by yourself. With him aggravating me for nearly a year with his nitpicking I did the job for the parts only and told him to leave and not comeback. Not a bad price to pay to get rid of a pest.

Now if I can only something that I can pressurize to apply the ACE/trans oil mix that it will not destroy.

[Arkie]

Intake valves stuck in both heads does not sound good.

I would think about bringing the piston up to TDC and with that being a OHV just remove the valve spring by hand and make a visual inspection.
If no rust seen I would suspect that high humidity got in the cylinder area and the stem is rusted on the other side and might move in with taps toward the piston.
I would take a vernier caliper and get a reading on how much of the valve stem is exposed and do as bsengine suggested with very light taps and read the mic again. If it moves any try doing a slight rotate of the stem with pair of pliers that are smooth jawed and a groove ground in the jaws. I have pair that I made for such.
If no go remove only one head and check. (might get an idea of the other head after checking the removed head.
Have to keep and heads up about the guide when they are stuck.

[bgsengine]

The customer tried tell me it only took 30 minutes to R&R the engine. Well it took over two hours getting it out and one hour getting it back in. But only took 30 minutes to rewire it. And an engine lift is very helpful when you are by yourself. With him aggravating me for nearly a year with his nitpicking I did the job for the parts only and told him to leave and not comeback. Not a bad price to pay to get rid of a pest.
.

Little trick to the shaft drive cubs that makes Engine R&R much faster - slit the bellows along the direction of the shaft drive (its plastic that fits between shroud and frame covering the flywheel screen) - zip ties to put back together after all done. With the slit bellows you just pop it off (check for zip ties at bottom before cutting though! Cub Cadet school back when I went to it in the late 90's recommended the trick...) with that bellows out of the way it is easy access to the 4 bolts that hold shaft drive to the flywheel so you don't have to separate the PITA flex coupling at all - 4 bolts on engine, 2-4 bolts to pop hood stand off (I did em with hood attached), disconnect gas line, throttle, choke, and wiring harness at connector (if they were not left off there are also hoist loops bolted to engine to use a shop hoist to pop engine out) so if it's a standard shaft drive cubby that hasn't been cobbled up or modified, I could usually pop the engine out in about 10 minutes, and have it back in place in about 15 to 20 minutes.... then just slip underneath and zip tie the bellows back together after squeezing it back in place over the shaft & screen.