2003 GT 235 dead cylinder on one side

[HoosierDoc]

I have taken excellent care of this mower for the last ten years and it finally has had its first problem. It is a 18hp Kaw and has 450 hrs on it. No smoke, no pop, no indicator that something was wrong. I went to turn PTO on and the blades were not moving at correct RPM so I shut it down. I pulled the deck out from under it inspected the belts/blades, nothing seemed to be out of sorts. I checked drive belt (original) it had cracks all over it so I switched it out. I started the mower. Again there was very little RPMs. I changed spark plugs and tested to make sure both sides were firing. They were equal and reactive. I went ahead and changed the coils because they looked pretty bad anyways. I then check the fuel pump. It had a new filter and was pumping fine. I checked air breather/ carb, it to was spotless. I then took off the right side (fuel pump side) valve cover...it was good. I then took off left side valve cover...the pushrod was not connected to the lifter on the bottom (exhaust valve). I reinsert the push rod and tighten the bolt. I took compression check on the right side it had 110 and left had 0. Oh boy. I unhooked the spark plugs and turned the key over. Air was blowing from exhuast valve. The lifters were moving and springs were operating. I need help.

A. Before I take off head to see if it is a stuck or bad valve...what torque should the lifter nut be and is there something else I should check.

B. If I take the head off should I look for damage/gap in valve....blown head gasket....etc

c. I won't be able to see the ring but on inspection through the spark plug hole the piston looks great. I should still check for hole or damage to piston/cylinder wall.

d. Anything that I am missing?

Any help will be great....I have no knowledge of small engines so be gentle...I am learning.

 

[jimbo64]

I have taken excellent care of this mower for the last ten years and it finally has had its first problem. It is a 18hp Kaw and has 450 hrs on it. No smoke, no pop, no indicator that something was wrong. I went to turn PTO on and the blades were not moving at correct RPM so I shut it down. I pulled the deck out from under it inspected the belts/blades, nothing seemed to be out of sorts. I checked drive belt (original) it had cracks all over it so I switched it out. I started the mower. Again there was very little RPMs. I changed spark plugs and tested to make sure both sides were firing. They were equal and reactive. I went ahead and changed the coils because they looked pretty bad anyways. I then check the fuel pump. It had a new filter and was pumping fine. I checked air breather/ carb, it to was spotless. I then took off the right side (fuel pump side) valve cover...it was good. I then took off left side valve cover...the pushrod was not connected to the lifter on the bottom (exhaust valve). I reinsert the push rod and tighten the bolt. I took compression check on the right side it had 110 and left had 0. Oh boy. I unhooked the spark plugs and turned the key over. Air was blowing from exhuast valve. The lifters were moving and springs were operating. I need help.

A. Before I take off head to see if it is a stuck or bad valve...what torque should the lifter nut be and is there something else I should check.

B. If I take the head off should I look for damage/gap in valve....blown head gasket....etc

c. I won't be able to see the ring but on inspection through the spark plug hole the piston looks great. I should still check for hole or damage to piston/cylinder wall.

d. Anything that I am missing?

had a friend that had this exact thing happen to him and all they did was adjust the valves---he said it was easy fix- have to get them right so you don't bend one- if you don't know how, i would look for someone who does to do this first time- i have never had to do it so i won't go there with some bad advice- he said one valve cover was cool, other hot-----let us know how you make out good luck:thumbsup:

 

[HoosierDoc]

Thanks...I am prolly just gonna have to suck it up and take it somewhere and have the valves checked....if it does need to be taken apart then I can alway bring it home and do it. It shouldn't cost more then $50.00 for a valve job, should it. I 'll have other side check just in case. Is there a retainer bar like I have my SB Chevy to keep the rockers from coming loose...obviously a 18hp Kaw doesn't put out the power of a SB but the vibration of mowing can/does shake the motor.

Yes, I just asked that...:smile:

 

[BBO]

It shouldn't cost more then $50.00 for a valve job, should it. I 'll have other side check just in case.

I am not so sure it's only a valve, but IF so I would have both sides done at the same time.
If the valves just need adjusting that's not so bad, but if they have to be removed to have ground, that's another.
You would need all new gaskets, and unless you do all the removal/assembly etc, this is likely a $350 job at a minimum.
I just hope you do not have a broken ring...
Zero compression does not sound good.

A rebuild might cost $1200 IF you can find someone interested, and you do not want to as how much a new engine would be.

 

[HoosierDoc]

I am not so sure it's only a valve, but IF so I would have both sides done at the same time.
If the valves just need adjusting that's not so bad, but if they have to be removed to have ground, that's another.
You would need all new gaskets, and unless you do all the removal/assembly etc, this is likely a $350 job at a minimum.
I just hope you do not have a broken ring...
Zero compression does not sound good.

A rebuild might cost $1200 IF you can find someone interested, and you do not want to as how much a new engine would be.

my fingers are crossed that it is just the valve adjustment. I am having it done now (both sides). If it doesn't work I'll take the head off and see what I have. Maybe just a bent valve, head gasket, or something not to bad. If it is a ring not sure what I'll do. If anything maybe I can find a good used motor on a junk mower. My mower is spotless and would hate to just toss it...I would hate to but $1500 into as well. :smile:

 

[HoosierDoc]

Just to give you guys who care an update...it was the valve retainer clip and exhaust valve. It was bent and wedged open.

 

[BBO]

Just to give you guys who care an update...it was the valve retainer clip and exhaust valve. It was bent and wedged open.

Wow. How do you suspect THAT happened? Did you fix it?

 

[HoosierDoc]

I don't know really. I neighbor of my friend works at JD and looked at with me. He said he has came across this before on this type mower (not often). He said it is a random occurance and was surprised it happedned. But that it was 10 yrs old without any problems so take it where I could get it. Luck that is. He said prolly should of had a valve adjustment done a few years back. That might of prevented this, but who knows.

In process of fixing. I bought new head, putting valves in this week. I went ahead and just changed it all out. Maybe cost more then it should. But the mower I think is worth it. All and all prolly gonna cost me $500.00 for this whole problem to be over but I really have not put anything into it for 10yrs, so Im not complaining. The way I see it is that it has less then 500 hrs. and barely a scratch. retail is still good on these tractors and I might just trade for a zero turn next year or so.

 

[BBO]

....In process of fixing. I bought new head, putting valves in this week. I went ahead and just changed it all out. .

Can you identify the part that was bent? (Click to enlarge)


You really replaced the head?


I like the GT series mowers.

 

[HoosierDoc]

Can you identify the part that was bent? (Click to enlarge)
View attachment 14994

You really replaced the head?
View attachment 14995

I like the GT series mowers.

#6- like it was folded. The spring was also broken
Not only was the retainer bent...the valve shaft opening had a huge gouge in the metal...I didn't really HAVE to change it. but there would have been a 50/50 shot it would just mess up. I could have use that sealer and tried,but the new head was like $125 and hell, I am not going to bitch when I had such good luck (knock on wood) with the mower for 10 yrs.