Old troy-built tiller with 3 hp tecumseh

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

ps: It is quite easy to pull the cylinder head on those engines... remove the pull start schroud and pull the gas tank aside and slip the head bolts out. Then you can see the condition of the cylinder wall - scoreing and such... look for a lip at the top of the cylinder where most of the ring wear happens...... like any other engine.... head bolt torque should be 200 inlb = 16 ftlb.

It may also be that the piston rings have rotated to where the gaps of the top two rings have lined up and compression is lost that way as well.

 

[waterinthefuel]

Re: Old troy-built tiller with 3 hp tecumseh

Let's try this:

View attachment 84138

KRS

I'm going to throw out some ideas based on my airplane mechanic knowledge.

That intake valve is some kind of grimy. You're probably not getting a good seat which is the problem with your compression. BUT, the bump thing you speak of might be the compression release. It's hard to tell from a single photo.

The cylinder wall looks ok. It has some wear though and a bit of scoring. I hate Tecumsuh. I'm glad they are out of business.

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

I'm going to throw out some ideas based on my airplane mechanic knowledge.
That intake valve is some kind of grimy. You're probably not getting a good seat which is the problem with your compression.

ummm....that would be the EXHAUST valve....hopefully you do know the difference...

The cylinder wall looks ok. It has some wear though and a bit of scoring. I hate Tecumsuh. I'm glad they are out of business.

Actually, they are very good little engines and not difficult to maintain if you have a clue what you are doing...

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

Let's try this:

View attachment 84138

KRS

=> KRS... if the head is still off, it would be a great time to set the points and timing.

 

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

The head gasket should be fine to reuse. I do it all the time on the Briggs from my lawn mower. Do you have an inch\lb torque wrench??

That is the intake valve that is so messed. Set the crank position so each of the valves is wide open and wiggle the valve parallel to and perpendicular to the crankshaft to check for relative wear in the valve guides.

What does the cylinder head look like for carbon buildup?? The cylinder and valves sure dont show an oil burner.

The cylinder markings don't look too bad. check the verticle marks and possible rough areas with your fingernail. Most of them look like scuff marks.

That governer shaft where the oil is leaking might be worn and no amount of other fixes may help. The splash lube system in the crankcase just overwhelms it.

Changing the breather body and using straight 30 oil may be the best you can do without boring and installing a bushing to resize the hole. Once you do those checks and know more, I would put it back together and give the new breather and the 30 oil a try. Instead of using the 21oz of oil just put in 18 for your first try to see if it still is throwing it at you. If the oil throw off is less, top it up an ounce at a time to see where the limit is. Just check the oil more often if your running with a lower level and no hill side use...

A re-ring and new valve guides with new valves would be the best but you likely could find a brand new 'will fit' engine for about the same money unless you can do it your self.

 

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

Seems to me I read somewhere that this was built in 1987. if that is true, then it should be an electronic ignition - no timing or setting.

if it is points, you'll need to remove the flywheel.

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

The head gasket should be fine to reuse. I do it all the time on the Briggs from my lawn mower.

+++. I've reused mine a few times and it works fine. If it doesn't...easy enough to change.

That is the intake valve that is so messed. Set the crank position so each of the valves is wide open and wiggle the valve parallel to and perpendicular to the crankshaft to check for relative wear in the valve guides.

Nope...that's the exhaust valve. I have a 3HP, 5HP and two 7HP Tecumsehs and they all have the exhaust in that position and I've never seen an intake valve in worse shape than an exhaust valve. (for heat wear).

What does the cylinder head look like for carbon buildup?? The cylinder and valves sure dont show an oil burner.

Agreed...looks like it's in great shape.

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

Seems to me I read somewhere that this was built in 1987. if that is true, then it should be an electronic ignition - no timing or setting.

if it is points, you'll need to remove the flywheel.

Missed that. All mine do have points.
If this one has electronic ign., obviously my comment about setting timing and gap with the head off was "pointless". :facepalm:

 

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

Let's try this:

View attachment 84138

KRS

.......



Nope...that's the exhaust valve. I have a 3HP, 5HP and two 7HP Tecumsehs and they all have the exhaust in that position and I've never seen an intake valve in worse shape than an exhaust valve. (for heat wear).

Just basing my ID as an intake valve on the fact that the valve on the left is larger than the right - the intake is always larger - and the flange that can be seen just above the same valve has the mounts for the carburator and the carb is mounted next to the flywheel shroud and you can see the flywheel on the left side of that picture....

I could still be wrong though.....:facepalm:

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

Just basing my ID as an intake valve on the fact that the valve on the left is larger than the right - the intake is always larger - and the flange that can be seen just above the same valve has the mounts for the carburator and the carb is mounted next to the flywheel shroud and you can see the flywheel on the left side of that picture....

I could still be wrong though.....:facepalm:

Guess I'm getting older....
Checked a pic I have of last time I had the head off one of the Tecumsehs and I would have bet the farm....
At any rate, from the picture that I took it is clear that I am...ummmm... less correct than you are....or WITF....apologies to you both. :redface:

 

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

Guess I'm getting older....
Checked a pic I have of last time I had the head off one of the Tecumsehs and I would have bet the farm....
At any rate, from the picture that I took it is clear that I am...ummmm... less correct than you are....or WITF....apologies to you both. :redface:

no problem from this end.

I 'bet the farm' on a piece of information that I gave on another forum a while back too.... was based on a SIMPLE math calculation.... totally blew that one even after it was pointed out to me. I was so sure of myself. ...:facepalm: .... :redface: .... .... :redface:

I'm probably wrong more than I am right..... according to my lifestyle manager anyway....

 

[Tim Frank]

Re: Old troy-built tiller with 3 hp tecumseh

no problem from this end.

I 'bet the farm' on a piece of information that I gave on another forum a while back too.... was based on a SIMPLE math calculation.... totally blew that one even after it was pointed out to me. I was so sure of myself. ...:facepalm: .... :redface: .... .... :redface:

I'm probably wrong more than I am right..... according to my lifestyle manager anyway....

...you're married, too, huh....?

 

[dolluper]

Re: Old troy-built tiller with 3 hp tecumseh

Hows the muffler

 

[stackz]

Re: Old troy-built tiller with 3 hp tecumseh

Want to order carb rebuild kit, but don't see any numbers on this carb; ideas?

View attachment 83231

read through the thread completely before posting. that plate the hose is running to on the left in this pic is the valve housing and is the pcv. I'd clean it out with some brake parts cleaner.

as to the missing screw, just take the one you have and match it at lowes. it doesnt have to "match" exactly, not rocket science, just a tiller engine.

as for the carb rebuild. unless a gasket tears I dont worry about it. I just tear them apart and clean everything with brake parts cleaner and slap it back together. if you tear a gasket, make another one with a sheet of gasket material you pick up at the auto parts store.

since you have the engine torn open, go ahead and lap the valves after you confirm they are straight.

though, at this point. I wouldnt even bother with that engine anymore. its a side mount type of engine so just measure the output shaft diameter (I'm thinking 3/4") and go to harbor freight and buy a knock-off honda engine and go to town with your newly repowered tiller:

http://www.harborfreight.com/2-1-2-half-hp-horizontal-ohv-gas-engine-97964.html

this is their regular price but I see them on sale every couple months for $89.00 AND you can usually use a 20% coupon as well lol. They are having huge parking lot sales next weekend so you can probably get the engine for $100

 

[dolluper]

Re: Old troy-built tiller with 3 hp tecumseh

I say a bad or clapsed muffler causing pressure and missing idle restriction screw are your problems...tecumseh must breath right....seen bad mufflers cause what you say about governor and even breather tube leaks....many other conditions also

 

[Pascal]

Re: Old troy-built tiller with 3 hp tecumseh

Don't think I can replace screw with one from lowes; it has a pointed tip like it's supposed to be metering fuel.

Won't junk this one yet, but it sounds like those HF engines are a good future repower.

Muffler was very very hard to blow through. It was spotless inside, no carbon etc. Opened it up just a little.

Still waiting on carb parts.

Put the head back on and when oiling the bolts the oil crept between the head and the gasket to the block. Will that cause a problem?

Took another look at the breather tube. I had the breather tube set in too far. With a brighter light I found the old mark on the tube which showed the depth it went into the breather, so I think I had it in too far and it was touching the plate inside and couldn't breath.

Thank you all for the help, I appreciate it,

KRS

That muffler should not be real hard to blow through. Some restriction - yes...

As for the oil, no - the oil won't hurt the head gasket seal on this application BUT the torque spec for the bolts is likely based on DRY threads. The oil will result in over tightening and the possible result will be pulled threads in the block. The other concern with your description of applying oil is that some oil is down in a blind head bolt hole in the block. If there is enough you will have a hydraulic lock when the bolt is tightened and the block may crack.

Do you have an Inch/lb torque wrench.....if not - finger tight + 1/6 turn to 1/4 turn should be close for a used gasket based on the tightening instructions that the manual gives for spark plugs. This method will eliminate the possible overtightening that would happen with oiled threads and a torque wrench. recheck them after the first use...


That mispositioned breather hose sounds like a winner for probable cause and for a fix by moving it back. Hope that works.

 

[john3931]

Re: Old troy-built tiller with 3 hp tecumseh

One thing you have watch with the idle circuit screw, there is a pin in carb that can fall down into the hole. If it does the screw will not go in. Also, make sure you have the little washer between the spring and o ring.

 

[dolluper]

Re: Old troy-built tiller with 3 hp tecumseh

You need a 640018 tecumseh screw....just seat it as there is no adjustment....thats why those emission carbs are so sick....they all run lean.....while the carbs apart pay close attention to the float bowl screw there is a very small hole close to the threads that needs to be clear......small strand from a COPPER wire works well to clear without damage the other hole is larger and easy to see on the float bowl screw.....when setting it up make you get the governor set right as well as the float level

 

[windy5849]

Re: Old troy-built tiller with 3 hp tecumseh

Congratulations, and great job on repairing the tiller.Success is a wonderful thing!

 

[dolluper]

Re: Old troy-built tiller with 3 hp tecumseh

Great to hear...now you can fix them Tecumsehs anytime...their not to bad when set up right