[boutin73]

Okay heres a good one for ya. I have an HT-20 with a Kohler 532. I started it up the other day and I am running on one cylinder. I pulled the plug and have plenty of spark. Whats bizzare is that it seems like this cylinder isnt getting any fuel. Im not sure how thats possible because theres only one carb (feeds both cylinders). Anyways I put some ether in the cylinder and fired it back up, but it didnt burn. Seemed like it just blew straight out the exhaust. I tried straight gas, same results. I put my finger on the plug hole while it was running and felt vacuum. I am stumped. I can see both valves are moving so no stuck valves. I assume if I have spark and I put fuel in the cylinder it would at least burn that fuel for a second or two. What do you all think? Any ideas before I start tearing into this project blindly? Thanks for any help.

 

[bushwacker]

If you have fuel and spark the only thing left to check is your compresion. You may have a blown head gasket. You could have a piece of carbon stuck on the valve not allowing it to seal. The valve seat could have worn and the valve lash may need to be opened up to allow it to close all the way. This last senerio could also have caused the valve to burn, with all the hot gases slipping by with the valve not closing all the way while it still had enough compression to run, then it gets so hot the edge of the valve burns away. My HT 23 blew a head gasket before so that is my first guess.

 

[boutin73]

Thanks for the reply. Any suggestions or tips before I crack into it? It will be my first adventure working inside the motor. I dont want to screw anything up. Ill check compression first. What should it be at? Thanks again

 

[rscurtis]

I would suspect that if you felt only vacuum, that piston isn't moving.

 

[blackjackjakexxix]

I have a couple blocks here if you find a broken rod,this seemed to be common on those tractors, I have had several that I parted just for that reason,(broken rod) Rick (724)944-5513

 

[boutin73]

Yeah vacuum is all I felt. Thanks Rick Ill keep it in mind I just bought the cylinder heads from ya cause one of mine has a crossthreaded plug. I assume its a big job to to fix a broken rod or the piston. Im pretty mechanically inclined so Ill be able to do whatever needs to be done, but I havent done much work on thses older small engines. Any dissasembly advice would be great. Thanks guys.

 

[wizof8]

First off, Keep the wife out of the garage, the fridge well stocked and raise the limit on your credit card. LOL

 

[boutin73]

Great advice wiz! Already two steps ahead of you!

 

[Tater305]

id pull the head off and look inside it. I pulled the head of my buddys HT23(blown head gasket) and it was pretty straight forward just remember were the bolts went I cant remember if they were all the same length or not but I try not to mix them up then go from there.

 

[Cvans]

I pulled the head off and it was an air filter screw stuck under the exhaust valve. Half an hour later it was and still is running like a champ.

 

[mrcaptainbob]

YAYYY!! How neat that it worked out so nice. The carbs on my HT-20's have a heavy gauge screen mesh pressed down into the throat. The mesh is small enough to keep those air filter screws and washers from falling in. Glad you got it worked out.

 

[Tater305]

good to hear you fixed it...Mrcaptainbob my buddys had the same thing in his carb I thought that was a pretty good idea.

 

[ratboy]

boutin73, this is going to sound a little odd, but have you tried a new spark plug in that hole? Maybe just switching the existing plugs from one side to the next? I've seen weak plugs fire in the open air but would not fire under compression. Also, run a compression test before acting too hastily on a tear-down.

 

[Cvans]

The carbs on my HT-20's have a heavy gauge screen mesh pressed down into the throat.

Sounds like an excellent idea to me. :fing32:
I wonder why the rest of the world hasn't caught on yet?

 

[boutin73]

I could only hope it is as simple as your case Cvans! I also have that same same heavy duty screen on my carbs intake. Maybe something smaller could get through. Ratboy I did try a different plug, not a new one though. There is spark and I was actually pondering if it was possible for it not to fire under compression. Maybe two bad plugs? I know when I pull the plug out it is soaked, but doesnt smell like fuel. Almost like water? But if water got in there somehow the Ether I put in should have burned. Im gonna try to crack into it this weekend (after the compression test of course). I just need to clean a spot in the garage, been working on fixing a water problem on that! I tell ya if its not one thing its two

 

[Cvans]

YES! Spark plugs can cease firing when put under compression. We used to have a spark plug tester that would check plugs with and without compression. You'd be surprised at how many plugs we found that looked just fine but would not fire under compression.

 

[mrcaptainbob]

You have a point there, Ratboy. I had spark plug issues on one of my HT's. The darn thing just quit running 'proper'. But there's nothing wrong with anything, including the plugs!! Yeah, well, two new plugs later and it ran like it's old self. However....I didn't throw those plugs away just yet. After all, they were almost like new!! For kicks-and-giggles I swapped them with the ones in the other HT. I have NO explanation for this...it ran fine with them, and in fact is STILL running them! I dunno... I am suspicious, though, that these tractors are all female.

 

[boutin73]

Well I wouldnt have thunk it but I guess it unanimous Ill get a new set of plugs (even though these only have about 20hrs on them) before I do anything. Cross my fingers.......

 

[Cvans]

I am suspicious, though, that these tractors are all female.

Ooooooo, ouch.:swow: I'm not going to let my little lady see that one. :fing32:

 

[mrcaptainbob]

Tractors, females, computers. (not in that order...) I love them all. Just can't figure them out sometimes....