My Tractor Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
87 Posts
Discussion Starter · #1 ·
I thought this was only a Kohler engine problem, but to my surprise!
My JD 265 with FC540V Kawasaki engine wouldn't start today. Didn't fire at all. Ran flawlessly yesterday. The first thing I checked was the choke, Bingo! The choke plate was out of place and one of the brass screws was missing, the second screw is 3/4 out but still holding. I can see that the missing screw is not in the intake, so it has gone into the engine.
I pulled the plug and scoped the inside with my cheap amazon computer bore scope. Couldn't see the entire piston crown, maybe 75% or so. Looks good to me! Can see several spots where the carbon has been knocked loose, doesn't look serious. I will replace both screws and just run it. Probably lucky those weren't stainless screws!
Does locktite work for brass into steel? Is there a better way to secure these little devils?
Thanks,
2477873
2477874
2477875
2477876
2477877
 

·
Registered
Joined
·
1,276 Posts
This can be a problem with the Briggs Intek single cylinder ohv engines, but for the throttle plate


Sent from my iPhone using Tapatalk
 

·
Banned
Joined
·
355 Posts
Don't cheap it out.
Pull the head .
I have seen almost new engines totally trashed by one of those screws
A previously mentioned stake the bolt
Put a rod through the carb throat so the head is sitting on it then a couple of taps on the thread end with a fine pointed centre punch will make sure it stays in place.
 

·
Registered
Joined
·
1,144 Posts
Had somewhat the same thing happen to a Bolens twin only it was one of the four screws holding the breather on the carburetor. Engine was running fine then all of a sudden I lost a cylinder. Pulled the head and one of the the four screws had lodged in the exhaust valve between the valve seats. The top of the head had a nice dimpled texture to it, clean as a whistle too LOL. Pulled the bolt out, put a new head gasket on and all was good. The four screws on the breather I retapped to the next size to clean up the thread and used Loctite, never had a problem..................Mike
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #6 ·
Don't cheap it out.
Pull the head .
I have seen almost new engines totally trashed by one of those screws
A previously mentioned stake the bolt
Put a rod through the carb throat so the head is sitting on it then a couple of taps on the thread end with a fine pointed centre punch will make sure it stays in place.
Thanks for the information on how to stake the bolt! I'm going to do a little more inspection before deciding to pull the head. I know it's the right thing to do, but I'm not in a great position to do that work right now.
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #7 ·
Update: My FC540V Kawasaki carburetor has steel screws holding the butterfly valves in place, not brass!
Does anyone know if these screws are "lock-tited" at the factory? I don"t see any trace of it on the one remaining screw.
The screws appear to be M2.5-.45-6mm.
My son brought over a decent bore scope and the only sign of the screw going through the engine is the one spot where the carbon is knocked off the edge of the piston crown. The rest of the piston crown is blemish-free. The bore is unmarked. We could only see one side of each valve, but they look normal, so I plan to just fire it up after repairing the carb.
 

·
Premium Member
Joined
·
5,515 Posts
From the service manual for the FC540V, it says "Apply screw locking agent to screws of throttle valve or choke valve. Do not allow agent to flow into shaft bearing surfaces".

I suggest googled for it yourself and download it for free. It's got all the info you need to fix pretty much everything for it.
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #9 ·
Thanks Dave! Great information! I didn't think of that, I will be downloading the service manual.
 

·
20,000 +posts!
Joined
·
20,953 Posts
This was a fairly common cause of demise for many Tecumseh HH series engines as well..
I have one I bought for a spare ,a HH120 12HP one,and I was reluctant to take the cylinder head off it because I was told it had rum well,and it did have excellent compression..and finding a new head gasket locally is usually a big pain..

I'm glad I did remove the head though--I found the top of the piston and the cylinder head above it all dinged up with impressions of screw threads,it looked like Trilobite fossils...and the brass screw from the throttle butterfly was firmly imbedded in the cylinder head,above one of the valves,which fortunately wasn't damaged,nor was the lifter or camshaft..and the cylinder wall was perfect,not a scratch in it!..
I am not sure if the head is cracked where the screw got punched into it,it may be,but I have a spare head,so thats no big deal..
I guess they used brass screws for a reason,hopefully if one gets inhaled,it being softer metal,it may not cause extensive damage..but it can!..steel screws would guarantee some bad things will happen..best way to secure these screws is to mash the threads on the side opposite the screw head after installing them with a tiny chisel or punch,mushroom it enough so the screw cant come all the way out if it ever loosens..
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #11 ·
This was a fairly common cause of demise for many Tecumseh HH series engines as well..
I have one I bought for a spare ,a HH120 12HP one,and I was reluctant to take the cylinder head off it because I was told it had rum well,and it did have excellent compression..and finding a new head gasket locally is usually a big pain..

I'm glad I did remove the head though--I found the top of the piston and the cylinder head above it all dinged up with impressions of screw threads,it looked like Trilobite fossils...and the brass screw from the throttle butterfly was firmly imbedded in the cylinder head,above one of the valves,which fortunately wasn't damaged,nor was the lifter or camshaft..and the cylinder wall was perfect,not a scratch in it!..
I am not sure if the head is cracked where the screw got punched into it,it may be,but I have a spare head,so thats no big deal..
I guess they used brass screws for a reason,hopefully if one gets inhaled,it being softer metal,it may not cause extensive damage..but it can!..steel screws would guarantee some bad things will happen..best way to secure these screws is to mash the threads on the side opposite the screw head after installing them with a tiny chisel or punch,mushroom it enough so the screw cant come all the way out if it ever loosens..
Thanks to all who suggested pulling the head! I realize that is the correct thing to do.
Can the head be pulled without removing the engine?
FC540V Cylinder head bolt and nut Torque: 52 N•m (38 lbf •ft). (from page 12 of the manual).
Is 38 ft-lbs correct? Sounds a bit high to me.
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #12 ·
To update this thread, I decided to pull the head, and upon removing the muffler I found that the muffler had a small hard object in it. I wasn't to remove the "bb" sounding object, or see it with my bore scope, but I knew the only small hard piece that could be in there was the one missing butterfly screw. I reinstalled the muffler, fired it up and have now run it for 1 hour since it ingested the butterfly screw. I expected to several hours on it bu now, but without any snowfall, I don't run the JD265. Thank you all for all the input on this.
 
1 - 13 of 13 Posts
Top