Kawasaki FH601V Compression Question

bertsmobile1 said:

Before you go any further I would whip out those guide plates clean them up & wack some paint on them.
I gather it gets a tad humid around your place with real cold nights & heavy dew.

SO some background might be good.
When did the engine last run ?
IS the loss of compression sudden or has it been getting harder to start for a while.
Also did you do the compression as per the manual.
You said you have worked on other engines so I hope that meas to rotated each cylinder to TDC compression before taking the readings & making the adjustments.

As for the plug, no colour is better than black.
If the engine is not running you will get no deposits on the plug.
If you have been cranking it for a while & it has not fired then the plug should be wet with fuel.
If not check the fuel cut off solenoid on the bottom of the carburettor.
If you get that much water in your rocker cavity chances are there is water in the solenoid & it has corroded closed.

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Put everything back together so I’m gonna hold off on cleaning up the guide plates until I figure out if I have to break this thing down or not.

I adjusted the valve clearance at TDC yes, and triple checked them. Adjusted to factory specs. When I checked the compression I simply put my compression gauge and cranked the engine over a few times. I did this multiple times both sides. Not sure what or if there is any other method. But again it wasn’t a leak down test, don’t have the equipment for that.

Also pulled the carburetor and cleaned it, plus drained the tanks and cleaned them as well. The carb has fuel in it as it drains out of the bottom from the drain screw.

Both plugs are new. The left cylinder is showing light blackening from cranking the engine. The right has zero discoloration and I can smell fuel on it.

This motor was given to me and has been sitting for quite sometime and supposedly was running good but I don’t really know that for sure.

If I’m getting drastically different compression readings between the two cylinders, with any engine I’ve ever dealt with that would indicate something like a cylinder that needs to be rebuilt. Why would this engine be any different?

Thanks

Usually on engines with ACR's , you won't get an accurate compression reading, why? Because the compression release is doing it's job.
If you had a way to spin the engine at normal running RPM it would be accurat e.

I believe with compression releases it usually drops the pressure to about 80 or 90 pounds on most small engines.
https://www.youtube.com/watch?v=jc3j4ShE-tk

Scrubcadet10 said:

Usually on engines with ACR's , you won't get an accurate compression reading, why? Because the compression release is doing it's job.
If you had a way to spin the engine at normal running RPM it would be accurat e.

I believe with compression releases it usually drops the pressure to about 80 or 90 pounds on most small engines.
https://www.youtube.com/watch?v=jc3j4ShE-tk

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Thanks thats a good video. Think I'll pick up a tester and do a leak down test.

What is throwing me on the compression is I assumed that the ACR would affect both cylinders but it would make sense that its only one cylinder.

Beau Yes do a leak down test, that will tell you for sure the rings ore leaking VALVES..... Where you at down here in Mardi Gras country Mon Ami ~!~! ??????

Fish said:

Fat Tuesday is not for another few days??

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Fish we been kicking it up in Eunice since Friday night down town, Maybe even before that LOL...........Schools close down for a few days too.... Stores close some banks close....... Cest La Vie..........

Boudreaux In Eunice La. said:

Beau Yes do a leak down test, that will tell you for sure the rings ore leaking VALVES..... Where you at down here in Mardi Gras country Mon Ami ~!~! ??????

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Boudreaux I’m planning on it. Just gotta get a leak down kit.
I’m over in Madisonville but wish I was in your neck of the woods. I’m originally from Gran Anse. But part of my family was from around Eunice. Hope you passed a good Mardi Gras!

Ok, so I finally got around to performing a leak down test on the engine.

On the right cylinder with both valves in the closed position at tdc I've got heavy air flow from the exhaust so obviously the exhaust valve is not seating properly. If I block off the exhaust I've got some air flow from the crank case and the gauge drops to between 45 and 50%.

On the left cylinder with both valves in the closed position at tdc I've got no air flow from valves. I do have some air flow from the crank case and the gauge drops between 40 and 45%.

I'm not sure whats normal for air flow around the pistons to the crankcase but more than likely less than what I'm seeing/hearing but the fact that its fairly even on both sides to me would seem like normal wear. Granted, this leak down kit is from Harbor Freight so not sure how accurate it is anyway. But again I do think there is obvious wear in the cylinders but seems as though engine should run even with that wear.

The problem appears to be with the exhaust valve on the right cylinder I suspected something was up with that cylinder to start with.

The valve stem does not appear to be bent and I don't hear any unusual noise when turning the engine over. But aside from pulling the heads to take a look at the valve any advice here would be appreciated.

Thanks

Make sure when you do your tests that you have clearance between the valve stem and rocker arm. (To make sure the cam isn't holding a valve open.)

The air you hear going into the crankcase is going past the rings. This is a sign of wear. How many hours on the engine? Has the air filter been properly maintained?

The air you hear going into the exhaust (or intake) is air leaking past a valve. I can't speak for the FH601V, but the manual for the FR651V thru FR730V calls for "cleaning the combustion chamber, check and adjust valve clearances, and clean and lap valve seating surfaces" 300 hours. I can just about guarantee that 9 out of 10 owners are NOT going to do that and if they do, are smart enough to not do it in the order specified.

It might be that the 300 hour cleaning is to prevent the problem you're having. But it wouldn't have helped the rings.

cpurvis said:

Make sure when you do your tests that you have clearance between the valve stem and rocker arm. (To make sure the cam isn't holding a valve open.)

The air you hear going into the crankcase is going past the rings. This is a sign of wear. How many hours on the engine? Has the air filter been properly maintained?

The air you hear going into the exhaust (or intake) is air leaking past a valve. I can't speak for the FH601V, but the manual for the FR651V thru FR730V calls for "cleaning the combustion chamber, check and adjust valve clearances, and clean and lap valve seating surfaces" 300 hours. I can just about guarantee that 9 out of 10 owners are NOT going to do that and if they do, are smart enough to not do it in the order specified.

It might be that the 300 hour cleaning is to prevent the problem you're having. But it wouldn't have helped the rings.

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Thanks. Yes I had clearance between valve stems and rocker arms and understand why the air is moving through the various parts.

Have no idea how many hours are on the engine but I can bet the valves and seats have never been cleaned or lapped. I guess I should pull the head and take a look at the valves.

Beau said:

Thanks. Yes I had clearance between valve stems and rocker arms and understand why the air is moving through the various parts.

Have no idea how many hours are on the engine but I can bet the valves and seats have never been cleaned or lapped. I guess I should pull the head and take a look at the valves.

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Well down here head gaskets are only $ 13 each so why not.
Push rof engnes are so easy to do head jobs on it is almost a crime not to.