Compression Testing KT 17 IH 782
 

Good evening,

I purchased a Harbor Freight Compression Kit. I ran the engine for about 15 minutes. I removed the plugs. The left plug was hot and the right pug was "room temperature". I removed the air filter. I attached the compressing tester to the right plug hole and the compression did not register. The left cylinder register about 65 PSI. I tried to duplicate the testing but the compression test gauge failed to move each time. Compression test was a dry test.

For a little more information, see my 782 carb thread from last week.

Any advice would be greatly appreciated.

Thank you.

Click on this link, and look at Page #13....... KT Service Manual

Thank you very much!

I read the reference and then read about the engine disassembly to get to the internals. I am not sure I am good enough to do this as I am a greenhorn.

Tomorrow, I may talk to a small engine mechanic who may be able repair an older engine. I would really rather do the repair rather than contract it out. I think it would be fun.

Do you think a novice could o the repairs?

You should have about #90 both sides on a normal engine.
It appears you lost one cylinder.
I don't know what you mean by "DRY" test.
You should have had the throttle wide open when cranking, to get an accurate pressure reading, if you didn't.

On the dead cylinder side, put your finger in the plug hole and crank it over, can you feel any air moving at all?
if not, you prolly have a broken rod and the piston is not moving.
you can confirm this by removing the cylinder head.
If it is a KT series 1, it has died a common death, sorry to say. :BlahBlah:
If the rod is broken,there is no "fix"
A replacement engine is in order.

Ok,
I went back and found the carb question you posted.
It is possible you have a problem with the intake valve.
Either way removing the head will get you an answer.
A novice can easily remove the cyl head.
Just follow the service manual, and we can help if you get into difficulties.
:beerchug:

Thank you.

I will give it a try.

As always, I really appreciate the great advice. The advice I have received on this site has helped me get the tractor running. Now this problem has shown up (as described in my thread about the 782 carb question).

I watched a YouTube video that showed how to do a compression test. The mechanic used the term dry test when testing the compression after the 10 to 15 minute warm-up. They followed up with a wet test where he poured a tablespoon of oil into the spark plug hole.

Quick question: I read through the engine disassembly section, after reading about the compression test. Do I need to remove the engine to remove the head and check the valve? Or to check valve clearances? Being a newbie at this, I am trying to learn and try to fix it.

I have looked for several years to find a good small engine mechanic for this old engine but have not found anyone interested in working on it.

Thank you for the advice.

Nope, you can remove the head as well as remove the valve cover (to check valve clearance) with the engine still in the tractor.

You are well on your way to being your own small engine mechanic :beerchug:

Thanks for the advice.

I believe I have the 782 fixed. The problem is a little embarrassing but here is the story. Several weeks ago, I noticed the 4 screws that mounts the air filter to the carb elbow were missing. I removed the carb and checked it for the screws. I figured I had removed them and lost them as I was working on the throttle. I also ran a magnet through the intake manifold as a caution. Today, I removed the heads and found 2 screws in the right valve and two screws in the left valve. Evidently the 4 screws traveled through the carb and intake manifold into the valves. I removed the screws and replaced the heads and tested. I have compression and the motor sounds good. I still need to finish installing the panels.

Thanks for the advice. Y'all gave me confidence to tinker and try to fix the motor.

Next project is to find a new PTO pulley for the mower deck. Then, repair the mower deck. The pulleys appear to be frozen. The PTO deck pulley is rusted out.

Don't sound right but if screws passed through carb to engine than you are screwed.

you got lucky, had they made it past the valves into the top of the "pistons" you would have been "pissed"
Now,
Did you retorque the heads after two heat cycles?
in other words running it till hot/operating temp 2 times.
If not, please do yourself a favor and do it.
Otherwise you will blow the 2 new head gaskets just as soon you work the engine.
( this tip is not in the service manual) :beerchug:

Thanks. As always, I appreciate the advice.

I will retorque after two heat cycles. I tightened the bolts in the order as prescribed in the manual. I used the same head gaskets as they looked in perfect condition. I am ordering two new head gaskets.

Do I need any type of gasket sealant on the new head gaskets?

I did not see any gaskets on the intake manifold. Are there gaskets?

I am not a mechanic but I am having fun tinkering with this 782. This forum has been a huge help!!!

Thanks.

There usually are gaskets at all ends of the intake manifold! I suggest you look at the exploded diagram in the Cub Cadet parts and service lookup to find your corresponding gasket(s).

For head gaskets, usually no sealant required and is not recommended. Again, refer to the service manual.

Yes there are gaskets on the intake manifold --But if you didn't remove it, or they were not damaged if you did, it is just fine not replacing them with new ones.:beerchug:
it is possible someone used some sealant like RTV, or other types instead of actual gaskets.

Now: it is always recommended that head gaskets are replaced when removed and since they do take a little bit of work doing it, it just makes sense as one does not like doing a job 2x.
All that said:
There are times, and I'm talking from personal experience, that one does not have a new head gasket on hand,---- or it just is not available and the engine needs to be put in use now, reuse of the old one, if in good condition works most times.
Soo you are having a good learning experience.
It is common sense if reusing the old gasket to try ones best to use it on the same cylinder it has lived on and in the same position in relation to which side faced the head.
When reusing a gasket, they do make a coating called "copper coat, it is a spray on and I've had good success using it over the years.

A new gasket unless specified, needs no coating.
You might get by without a retorque since the "experienced" gasket has already compressed itself prolly all it is going too,

where as you will be very surprised just how much a new gasket compresses after it goes through several heat cycles.
You did good June bug!
If it were my job, I'd have the new gaskets on the hook ready for use, when and if the "experienced" gasket(s) fail.
Now don't feel bad that you "screwed" yourself, you have learned something as well as all others that have, and will read this.

Book Larnin' is good, but the "Skool of hard knox" is a never forgotten education.:beerchug:

Put a little lock tite on those air cleaner screws. :)

And use "small thread locker" type or they not ah gonna remove easily or jus' plum snap off :biggrin2:

Locktite lite:)

I appreciate the great help this site offers. I will use the thread lock. The engine sounds good to my untrained ear.

I had never attempted engine repair before COVID hit. Since I was not traveling, I decided to try and enjoyed it. I figured I had nothing to lose since the small engine shops I took my two CC to condemned them. This forum has been a huge knowledge base for me. I got the Cub Cadet 1320 running good. The 782 is good. It has been fun.

Here is a link to the 782 running after the 4 screws were removed from the valves. https://youtu.be/miJ3N5ig9jw.

Thank you again.

Rubber Cement!

Don't forget the Split lock washers..... often lost on previous engine services.

No,
rubber cement is for rubber bolts attaching rubber baby buggy bumpers :biggrin2: