Compression

[GSPHUNTER]

I've pretty well got my mind made up, but I guess I need to write this any way. My buddy is getting out of the biz this year and he's trying to sell his
52" Ferris to me.

I ran a comp. test on a 23 hp Kaw engine and got 120 from cylinder 1 and 90 from cylinder 2. Needless to say, this was alarming. Anybody have any ideas of quick fixes that could be causing this?:hammerhead:

[newz7151]

HG on CYL2 ?

[Jason Pallas]

That's certainly a possibility.

[GSPHUNTER]

HG = Head Gasket? I'm assuming that if this is the problem, it is a pain to fix and not worth buying a headache.

[newz7151]

HG = Head Gasket? I'm assuming that if this is the problem, it is a pain to fix and not worth buying a headache.

Depends on what caused the HG to malfunction.

[MowerMedic77]

Are you performing this compression test with the engine cold or after it has had time to get to operating temp?

[GSPHUNTER]

I did it cold real quick last night, and I know it is supposed to be at operating temp. I'll test it again tonight after it's warmed up, but do you really think it's going to make a 30psi difference in compression after it's warm. Also, the mower had been running about 5 hrs before I did the test, so oil should have still been on the cylinder wall I would think.

Thanks for the replies.

[shepoutside]

If it is less than expected, squirt a small amount of engine oil in through the spark plug hole so it coats all around the edge of the piston and cylinder.

Repeat the compression test.

If the pressure reading is now acceptable, then the rings need replacement or the piston/cylinder are excessively worn. If there is little change, there is a valve problem.

If the measurement is very low under both conditions, there may be a blown head gasket or damaged (punctured) cylinder or head. (Or your engine has a compression release mechanism which is reducing the reading)

[CarterKraft]

just a guess but doesn't that engine have a low RPM compression release on the cam?

If so that would bleed the cylinder pressure off giving a false reading?

Just a thought, I haven't worked on air cooled in a long time.

[GSPHUNTER]

Well, I went out last night and fired it up for about 5 minutes. Tested the low cylinder first this time and it read 110 psi. Then I tested the other cylinder and it read 130 psi, so I closed the variance a little between cylinders. That still seems like a pretty high difference though.

Also, this is a 2004 Kawasaki with approximately 1000-1200 hours on it.

Thanks

[MowerMedic77]

Is this a FH680V? If so the min. compression reading allowed is 390KPA or 57psi. That many hours also may need valve adjustments, ask you buddy how many he has done or had done. Kawi req. every 300hrs as part of normal maint.

[GSPHUNTER]

I can guarantee no valve adjustments have been done on this mower. I'm pretty sure when it came to maintenance his philosophy was less is more.

The serial number on the motor is 3KAXS675SCA.

Found another questionable thing on it last night. If you grab the top of the spindle on top of the deck, should there be any play in it at all if you wiggle it. Two of the spindles do this, and one doesn't.

Sorry for all the questions, but this is a tough position to be in. My buddy is getting out of the biz and giving me all his accounts and selling ?me? his mower, so I don't want to piss him off. I also don't want to get in mid season and realize I've got a huge problem on my hands.

[MowerMedic77]

Found another questionable thing on it last night. If you grab the top of the spindle on top of the deck, should there be any play in it at all if you wiggle it. Two of the spindles do this, and one doesn't.

The best way to check for bad spindles is(MOWER OFF:)) remove any tensioned belts from the pulley and grab the blade tip from underneath and try and move the blade up and down and spin the blade and listen for loud growling sounds. A little play is not horrible but obviously will not get better, but I would replace anything that seems suspect before season starts.

[jkason]

Well, I went out last night and fired it up for about 5 minutes. Tested the low cylinder first this time and it read 110 psi. Then I tested the other cylinder and it read 130 psi, so I closed the variance a little between cylinders. That still seems like a pretty high difference though.

Also, this is a 2004 Kawasaki with approximately 1000-1200 hours on it.

Thanks

1000-1200 hours?

Rebuild or run away.

[jkason]

Well, I went out last night and fired it up for about 5 minutes. Tested the low cylinder first this time and it read 110 psi. Then I tested the other cylinder and it read 130 psi, so I closed the variance a little between cylinders. That still seems like a pretty high difference though.

Also, this is a 2004 Kawasaki with approximately 1000-1200 hours on it.

Thanks

1000-1200 hours? Little to no Maint? Compression problems? Questionable deck spindles? Belts are probably worn, too.

Rebuild or run away.

[Mikes Machines]

most engines now days have an automatic compression release. this makes it easier to start and you will never get a "GOOD" compression number because it is designed to bleed off a little compression at cranking speeds, a much more accurate test would be a "leakdown" test, this is where you pressurize the cylinder at top dead center on compression stroke and see how much leaks past the valves and rings, the tester has a gauge on it to tell how much leakage you have, you can listen at the carb, muffler output and the dipstick for air coming out to give you a clue to what is actually leaking

[GSPHUNTER]

I'm begining to think runaway too. I did talk to a Ferris dealer, and they said the same thing about comp test. The compression release will throw it off. I don't have the equipment to do a leak down test.

Like I've said before, I'm in a tough spot. I keep all my equipment at this guys place rent free. It's gated and locked, out of the weather, and fairly close to home. He's giving me accounts now that he's out of the biz.

I think I'm going to just have to tell him to sell it outright, w/o bashing him for his lack of maintenance. I'll clean it up a bit for him so it's easier to sell and to thank him for helping me out with storage.

Thanks for all the help guys.

[Valk]

Ain't nuthin' wrong with wanting a fresher (if not new) mower with a lot less miles on it. He'll likely easily sell it this time of year...try Craigslist.

Ass-u-ming this mower is not a moneypit...it may make a decent backup mower.

[topsites]

Who cares, one of my best mowers is 10 years old, looks like hell but runs as good if not better than the '05.

Since it's used and a spring chicken it ain't I would see about gaining a fair blue book value for the machine and let it go at that. You'll always have some repairs, it doesn't sound that outrageous unless it's just falling apart...

No, the spindles shouldn't have any play in them, but some of mine do.
You might have to replace a spindle bearing or two before long, but that's normal for any used mower.
I think the engine's ok, you won't get to the bottom of the psi discrepancy and it is possible one cylinder is stronger, so?
Give it an oil change and start running synthetic in it, give that mower some TLC and she'll be gtg.
And I would run it, keep up on the maintenance yes but run that beotch till the wheels fall off.

[Bill Kapaun]

I would make sure the valves from each cylinder are set the same. If one is a little looser than it's "equal" on the other cylinder, it may be having a slightly different effect on the compression release. If that's the case, 20 PSI is nothing.