Did my compression test, interesting, tried some fixes

OK,

So. I was able to get the flexible hose with the combination 18mm/14mm head threaded into the block. No elbow required.

I'm not a fan of the quick connect between my compression tester's hose and its gauge, however. It was sloppy. I had to push the gauge onto the hose hard while cranking the tractor to get the gauge "catch" its seal. Once it caught, it held pressure and didn't leak between strokes.

Assuming cylinder 1 is the radiator and 4 is the furthest back, my dry readings were:

100
0
95
62

Yes. 0 for number two. The starter turned the engine with no labor whatsoever.

My wet readings were:

110
60
110
65

Notice that I had a wet reading for cylinder number 2. I wasn't even going to try it, but I poured in the teaspoon of oil and gave it a few cranks. The first couple of cranks were zero, just like before. Then it caught and gave some compression.

So, I concentrated on cylinders 2 and 4.

I poured a little bit of ATF into cylinder two and let it set. After about 10 seconds, it was pouring right out of my carburetor's air inlet; which I had removed the breather pipe from as per compression test instructions.

I figured that the cylinder was either on the intake stroke, or the intake valve was stuck. So, I cycled the engine a little and put a little more ATF in the cylinder. Some more leaked out of the carb.

What are the chances that I hit two intake strokes?

I figured that the intake valve was sticky. Hence the zero dry reading and the 60PSI wet reading. The oil must have been loosening the valve a little.

So, I poured in a little more ATF, put my finger over the hole and cycled the starter.

That yielded intermittent compression, but it seemed to get stronger.

I repeated that cycle of adding about a teaspoon of ATF and cycling the starter a few times with my finger over the hole. It got so that it was blowing my finger off of the hole and blowing ATF vapor around on the compression strokes every time, not intermittently.

I did another compression test on number 2:
110PSI (obviously wet)

I did the same thing to cylinder 4; as in, I poured in a teaspoon of ATF, put my finger over the hole, cycled the starter a few rotations...repeat about four times.

At this point, I cleaned up my spark plugs and ran the ends over a MAPP gas torch to ensure no fouling and put them back in. Reconnected my coil 12V wire, my spark plug wires and my air breather pipe and fired up the tractor.

SMOKE!!!!!!!!!!!

Of course, all of that ATF in the cylinders and intake.

But it ran better than before.

I ran it up and down the road in high gear at full throttle to work it over. It still had a little skip to it, yet better than before.

I adjusted my carburetor.

I can now get it to run perfectly smooth, no skips at about 1/3 to 1/2 throttle.

Above that, it has a little skip, and there's no carb adjustment that can get of that at this point.

So my thinking is that I now have one or combination of issues:
-A valve or two that now works well enough to pass a compression test, but they're still sticky enough to be "slow" so they can't keep up when the engine is revved.
-Perhaps now the valves are running OK and I'm finally down to a carb issue. For instance, I can thread the high speed needle valve (the diagonal one on the front) all of the way out (I mean completely...removed from the carb), and the engine runs with the same little skip at high speed and slight hesitation when the throttle is goosed. Shouldn't that flood the engine?

If you can remove the main jet the one you pulled out and still run you have a clogged passage way in the carb and that maybe why it still does not run as it should. You may also have a couple valves that need the tappets adjust a bit so the gap is a bit wider. Once you get the carb cleaned out you might also try running it with a mix of 1qt ATF to 3-5 gal of gas to help clean and free things up. By the way main jet all the way out says float bowl vent is clogged up

If you will recall, I suggested that you
record 3 readings for each cylinder. The
first reading was to be your valves seating.
So, you might want to do the test again as I
suggested.
75 Tips

(quoted from post at 13:00:05 11/21/15) If you will recall, I suggested that you
record 3 readings for each cylinder. The
first reading was to be your valves seating.
So, you might want to do the test again as I
suggested.
75 Tips

Click to expand...

I remembered that.

I tried recording that first number, but it was very erratic, due to the quick-connect coupler on my compression gauge. I had to push the quick-connect together and hold it together as compression built up. Sometimes, it would catch that first stroke as the valves seated. Sometimes it wouldn't, and it would take a couple of strokes to get enough pressure into the fitting to get it to hold.

I wrote some readings down, but I couldn't get them for every cylinder.

I didn't really trust those readings anyway.

I've already done the ATF in the fuel trick suggested by Old. I remembered it from some of his previous posts to others' questions.

I ran it for a couple of hours like that today as I did chores. Going to check into cleaning out the carb as soon as I get the starter replaced on our other tractor; which might be tomorrow.

I put a carburetor kit into it today.

Took it back out and cleaned the barn with it and then adjusted the idle and main jets.

It gets a little better with each maintenance item. This tractor is sort of like an onion. It seems that it had multiple issues: ignition, valves and carb. The problems all interplayed together, and removing one problem unmasked another.

I have a 1 quart ATF to 3 gallon mixture in the tank, and I'm going to run that through it this week. That will last about 5 days of barn cleaning.

Next weekend, I want to change all of the fluids for winter. Any recommendations on what I should do this week to prepare for that? As in, given that this tractor seems to have a lot of gummed up parts, my guess is that it would be smart to add something to the crankcase and the transmission this week to de-gum and loosen everything up before I drain the old fluids next weekend.

Any favorite tricks for that?

In a couple of weeks, I'll run another compression test to see how the valves have done and if they've stayed loose. Getting to my valve covers is going to be a project. My manifold bolts look like unrecognizable lumps of rust, but I know that I'm probably going to have to go there sometime to perhaps get to the very bottom of my valve issue.

" my guess is that it would be smart to add something to the crankcase and the transmission this week to de-gum and loosen everything up before I drain the old fluids next weekend.

Any favorite tricks for that?"

Yes.

Do not waste your time or money on snake oil.

Just change the oil & filter. (see tip # 6)

I'd save changing the hydraulic fluid until you have time to drop the pump & clean it.....unless it's milky & full of water. (see tips 3 & 4)

Sane w/ the cooling system; save changing that until you can reverse flush it. But do check the anti-freeze. And make sure it has a t-stat. (tip # 25)

Don't forget to check the torque on the head bolts & rear wheel nuts annually.

No matter what else you do, the battery must be fully charged. A float charger is helpful; not a trickle charger, but a float charger. (I use Battery Tenders on all my tractors; * see below) If you need to jump it, see tip # 43. Your battery loses 33 percent of its power when the temperature dips below freezing, and over 50 percent of its power when the temperature falls below zero. A fully charged battery will not freeze until -76?F; however, a fully discharged battery can start to freeze at 32?F. So??keep the battery fully charged!

Clean grounds & battery terminals are always important. Don?t forget to loosen the starter from the block (see tip # 36) and polish the block & all starter mating surfaces w/ sandpaper to insure a good electrical ground.

If you can?t remember the last time you replaced the battery cables, it?s time to do it. Just because the terminals are clean doesn?t mean there is no corrosion under the insulation. And, this is another case where size matters (see tip # 41)

A charged battery, clean grounds & new cables aren?t going to mean much if the tractor needs a tune-up. At a minimum, every fall, remove the cap, check the points for pitting or burning, re-gap them & put a dab of lube on the cam. (BTW?..if you?ve wondered why some folks get years of use out of a set of points??.this is one of the reasons).

Things that aren?t all that important in warm weather become serious when it gets cold?like timing. A few degrees of timing either way at 60 or 70* isn?t likely to result in a ?no-start? situation. Well, it can at 10 or 20*. Check the timing!

Distributor gaskets are important on a sidemount & critical on a frontmount. As is the gasket under the coil. Just like with the battery cables?.if you can?t remember when you replaced the gaskets, do it this year.

Push the clutch in when you start the engine (tip # 29)

Oil viscosity can make a difference. If the tractor is going to be consistently operated below 20* F, switch to SAE 5w30 or even SAE 5w20.

Pull the air cleaner cup & check for water.

This tip won?t make it start easier, but it will make it run better: turn the main jet out ? to 1 full turn for cold weather operating. Cold air is denser so you need a richer mixture.



* Battery Tender website: http://www.batterytender.com/
75 Tips

Thanks.

The part about pushing in the clutch to start the engine is something that I've already learned by experience. It's only what? 23hp? I always push the clutch in out of habit, and I can feel the engine load when I let up, especially if it's cold outside. Must be the loading of turning shafts and such through the back end matters to such a small engine.

I usually hold the clutch down for about a minute or so and let the engine warm up before going about half throttle and letting up on the clutch. It seems to like that.

I'll check into dropping the hydraulic pump and cleaning it out. I want clean fluid with no water in it for the winter.

The "no snake oil rule" seems reasonable. I'll just watch the color of my oil over the winter and change it out if it looks like it's starting to blacken up from picking up crap in the engine.

" I'll just watch the color of my oil over the winter and change it out if it looks like it's starting to blacken up from picking up crap in the engine."

Don't worry about it picking up crap from the engine, use detergent oil & rely on your filter to deal w/ that. The oil will change color from combustion byproducts anyway.

" I'll check into dropping the hydraulic pump and cleaning it out. "

You'll be glad you did that.

With all of the fluid drained out, (see tip # 3) block the front wheels & get the rear wheels up at least a foot. (you'll see why soon enough) Remove the 4 bolts holding the PTO shaft in & pull it to the rear & out of the tractor. Loosen all of the bolts. Remove all but 2 corner bolts. Then, carefully remove them. If you are lucky, the pump will drop free (and dump a pint or so of hydraulic fluid down your sleeves). If not, wrestle it free. The pump has 'ears' that fit into the housing; wiggle it a bit & it will drop free. If you have the rear tires a foot or more off of the ground, you will have enough arm room to hold the pump & lower it at the same time. Put it on your work bench & remove the safety valve (p/n 638) and the control arm lever (p/n 643) which will allow you to remove the intake & exhaust valves (p/n?s 640 & 698) Drop all of it in a bucket of diesel (or mineral spirits) or your parts washer & let it soak overnight. Once it has a good soaking, get it on the bench & start blowing it out w/ compressed air. Run cleaning fluid into the hydraulic discharge near the test port & make sure you get a good flow out the small hole in the side of the pump were the control valve fits. I don't see much need to pull it down any further just to clean it. But, I always replace the safety valve (p/n 638, about $25) Reinstalling the pump is harder than pulling it out because you have a gasket to worry about. (no sealer on the gasket) And, you will probably need a helper to guide the control rod into the pump rocker shaft unless you?ve done this 6 or 7 times before!

While you have the PTO shaft out, it would be a good time to replace the seal on it. It's got two spring clamps around it. Take your needle nose pliers & remove the one in the front. Then, hang the shaft & bearing housing in your vice & tap the butt end of the shaft; the bearing cap will come off (and the shaft will land on your foot). Then, remove the other spring clip from the other side of the bearing. At this point, remember that you never bought a seal driver & go get a BF socket & drive the seal out. If you have the new style seal, the white side goes out. (open side to the oil) Put some grease on it.

Contrary to conventional wisdom, not a lot of water gets in the oil from the shifter boot. Of course, if it's bad, replace it, but you get water from the draft control spring & the dipstick. But, most water is just a byproduct of the heating/cooling cycle of the oil.

You?ll need a pump gasket, safety valve, inspection plate gasket(s), PTO seal, PTO gasket, gasket sealer & 5 gallons of fluid to do all of the above.
75 Tips

you can remove the valve covers for a look at those stems. might at least celan up the exposed part and with with soemthing like acetone.

You certaintly CAN have stuck open valves. BTDT...

(quoted from post at 07:59:21 11/23/15) you can remove the valve covers for a look at those stems. might at least celan up the exposed part and with with soemthing like acetone.

You certaintly CAN have stuck open valves. BTDT...

Click to expand...

I know that a valve in one cylinder was stuck open enough to give a big fat zero on the compression test initially, until it got loosened up from some ATF in the cylinder and starter cycling, described above..

Chances are, if it was stuck that badly, probably a good chance that it isn't going back to perfect with just a little ATF in the gas.

I just dread taking off the manifold to get at the valve covers, but I know that should be on the to-do list one of these weekends.

Our other tractor is back in service, though; so there isn't as much pressure to only do things that I can get done between barn cleanings.

In the past I have pull the hood off and with the spark plug out been able to push the valve closed and in turn over time and doing it a number of times got a valve to work the way they should. Between ATF and opening and pushing them closed they cleaned up and started working correctly

(quoted from post at 10:29:49 11/23/15) In the past I have pull the hood off and with the spark plug out been able to push the valve closed and in turn over time and doing it a number of times got a valve to work the way they should. Between ATF and opening and pushing them closed they cleaned up and started working correctly

Click to expand...

That's a definite ninja move right there. I'm jealous of your ingenuity.