Kawasaki FR691V cam lobes with ball bearing

[Rocket Surgeon]

Regarding the 180 psi compression:

Is it possible that I am measuring the compression improperly? I'm removing one spark plug and screwing in my trusty Harbor Freight gauge. I've been measuring it with the carb removed. (not removed for the test, it just happened to be off).

The service manual says to open to full throttle and full choke, but frankly I don't see how those directions would affect the measurement.

With battery disconnected, I crank it until the pressure gauge stops increasing...per the service guide instructions.

It's also curious that the Husqvarna service center said that 180 psi was ok. Personally I've never heard of an engine with compression that high.

Slomo:Google says the FR691V has a compression ratio of 8.2:1.

 

[slomo]

To clarify: the valve guide on the valve that bent the valve push rod sits 0.040 in. above the height of the other valve guide in the same head, measured with the valve oil seals removed. Anytime I said "rod", I meant "valve push rod". Anytime I said "guide" I meant "valve guide". When I said "twice bent rod" I was referring to the valve push rod which, on two separate occasions, was found to be bent. In both instances the valve push rod was replaced.

I believe the bent valve push rod issue is now resolved. Thanks for that.

Dunno what pictures you'd like to see. There is no dirt or clogged fins to show, as the engine was pressure washed when removed from the mower prior to disassembly. The head with the out of place valve guide has been replaced with a new head. Two of the four valves have been replaced, and all four have been lapped prior to installation, with the valve clearance set to 0.004 in.

So the engine "was' pressure washed. Which tells all of us here, that engine was filthy. You probably washed off the evidence.

So you have a new head installed and valves are set. Should run like new.

slomo

 

[slomo]

Regarding the 180 psi compression:

Is it possible that I am measuring the compression improperly? I'm removing one spark plug and screwing in my trusty Harbor Freight gauge. I've been measuring it with the carb removed. (not removed for the test, it just happened to be off).

The service manual says to open to full throttle and full choke, but frankly I don't see how those directions would affect the measurement.

With battery disconnected, I crank it until the pressure gauge stops increasing...per the service guide instructions.

It's also curious that the Husqvarna service center said that 180 psi was ok. Personally I've never heard of an engine with compression that high.

Slomo:Google says the FR691V has a compression ratio of 8.2:1.

Sounds like you measured the compression correctly. Wondering if that gauge is functioning proper? 180PSI sounds like your combustion chambers are full of carbon bumping up the static compression. I would think, your engine should read around 80 to 150psi max. Have you checked your cam timing?

Should be full throttle and NO choke. If Husky said 180psi was good then you are golden. Again you see those readings in racing engines with a lot of compression.

slomo

 

[Rocket Surgeon]

Engine was not filthy, just a little dirty. The fins all looked brand new and have never been clogged. It has been established that the valve guide softened and relocated, so at some lever it overheated.

I think we are done with the valve issues.

Per the previous posts: after replacement of the valve push rod, the engine does not seem to run smoothly, has white to blue-white smoke out of the exhaust. Seems to have fouled wet plugs. The wet seems to be oil. The compression seems unnaturally high.

Any ideas?

 

[slomo]

Engine was not filthy, just a little dirty. The fins all looked brand new and have never been clogged. It has been established that the valve guide softened and relocated, so at some lever it overheated.

I think we are done with the valve issues.

Per the previous posts: after replacement of the valve push rod, the engine does not seem to run smoothly, has white to blue-white smoke out of the exhaust. Seems to have fouled wet plugs. The wet seems to be oil. The compression seems unnaturally high.

Any ideas?

To add on more fuel to the fire, it's just a push rod. It doesn't actually push on any valves directly.

So you now have an oil issue. Head gasket good? Head torqued proper? Engine block BREATHER hose going to carb, clean and clear? Valves adjusted proper? Some engines require the piston to be 1/4" INTO the bore when setting valves. Check your engine manual.

Open your oil dipstick tube with the engine running. Just loosen it and let it sit on the threads. Tell us if the engine is trying to puff or blow the dipstick up out of the oil fill tube.

Next stop would be piston and rings.

slomo

 

[Rocket Surgeon]

Slomo: The only timing check that I am aware of on this engine is ensuring the alignment of the punch mark on the cam gear and the crankshaft gear. I did check that and they are aligned. All gear teeth look like new.

I don't see how the ACR would affect the compression test anyway, since I would think the cam balls would retract during the test, but as I said, the cam and ACR seem fine.

I'll jerry-rig up a test for that quality HF compression gauge. Based on past experience, I've sworn not to buy any HF crap with a meter or gauge in it. It's always a mistake. I'm constantly walking the line between by own cheapness and the complete and utter lack of quality at HF. Guess they count on that. I have a second failed mower/atv lift in the truck awaiting return to them right now.

I checked the crown of the pistons for fouling and build up, but they seemed ok. I guess to be sure I'll pull the pistons and check the rings.

The kawasaki engine service manual states yada yada yada if the compression is out of specification...and then lists no specification within the manual. I think I read online somewhere in a forum that the upper range should be around 120.

 

[Rocket Surgeon]

Slomo:

I know the valve push rod doesn't push directly on the valve, however it is the push rod associated with the valve. I assume you're messing with me.

Head gaskets = brand new
Heads torqued to spec (oh god, its a HF torque wrench)
Checking the breather hose/port tonight, will advise.
Valve clearance adjusted to spec. = .004 in. (you don't actually adjust the valves, rather you adjust the clearance between the rocker arm and the valve stem, he he...my turn!)
I can't do the dipstick test yet, as the motor is disassembled on the bench. Will keep in mind to do after re-installation.
The service manual didn't mention pushing the pistons into the bore.

I will pull the pistons and check the rings.

Thanks.

 

[Scrubcadet10]

Have you checked the flywheel key for proper alignment?

 

[slomo]

Slomo:

I know the valve push rod doesn't push directly on the valve, however it is the push rod associated with the valve. I assume you're messing with me.

Head gaskets = brand new
Heads torqued to spec (oh god, its a HF torque wrench)
Checking the breather hose/port tonight, will advise.
Valve clearance adjusted to spec. = .004 in. (you don't actually adjust the valves, rather you adjust the clearance between the rocker arm and the valve stem, he he...my turn!)
I can't do the dipstick test yet, as the motor is disassembled on the bench. Will keep in mind to do after re-installation.
The service manual didn't mention pushing the pistons into the bore.

I will pull the pistons and check the rings.

Thanks.

2-chey' buddy. You got me on the valve clearance thing. Time to clean up my game LOL.

You might have some stuck rings ON the pistons. That could burn some oil. Make sure you have a proper ring gap. Now you got me double looking at what I type LOL. Making sure "I" send out the proper terminology.

slomo

 

[Rocket Surgeon]

I have not checked the flywheel key for proper alignment, nor do I know how to do that. I'm not sure how a flywheel key could have become unaligned.

Tonight I checked the HF compression gauge by pressurizing it with my compressor, and it agreed to the psi with the gauge on the compressor. YES, the compressor is from HF as well, so I suppose a conspiracy between HF suppliers is still a possibility.

I removed both pistons, and they both, along with the rings, look as though they have never been run.

I don't know where to go from here.

Tomorrow I'll disassemble the crankcase breather assembly and clean with brake cleaner, then I'll reassemble the motor.

If it still has problems, I'll shoot myself in the head...or buy a new mower.