Ariens yt12 with replacement engine B&S 28r707

[Fish]

Just doing a light cut illustrates the warpage that can occur from heat, notice the cut is thinner on the one side, which is why recutting is needed.....

 

[Fish]

Here is the valve about to be recut!!!!

 

[Fish]

First cut shows little warpage, a few more turns, it is like a new valve!!!

 

[Fish]

Just lapping a valve is a poor repair.. Which is why the seats are cut 1 degree off, that gives the good seal.

I worked at "The Mower Shop" in Louisville a few years back, and my workspace was pretty crowded, and on of the problems was an old drill press. I requested that it be taken out, so I could work in this small space.... No, "we use it a lot!!!!!"

Turns out that is how they recut/refaced their valves, they just put the valve in the chuck, fired it up, and just held sandpaper on the valve face, and charged the customer $8 for the "recutting" job!!!!!!

 

[Xxtjtheboater95xx]

I did put a brand new head gasket on yesterday and there was still air coming back through the carb, FYI. ( may be due to the cold outside air?)

Anyway, that's a huge job as I would have to deliver the tractor to someone or take the whole engine off the frame. The valves though don't seemed to be warped at all. But wouldn't a compression test tell me that the valves are not seating properly or that the valve seat(s) are loose? As compressing air in the cylinder is the most important part.

Also I think I'm going to try the old flywheel again because that was the only thing I changed before this all took place, but you haven't said anything about a flywheel being a possible issue.

Also, I did get the engine to run a little bit longer yesterday by adjusting the mixture screw but it still doesn't sound normal.

Is the valve clearance always supposed to be measured at tdc or is there some place I can find the exact place to measure it because the manual only gives me the clearances and not when to measure them.

P.s. you're right, I do need a good neighbor.

 

[Fish]

Yes, you need to rotate the engine until top dead center, both valves will be fully closed {should be anyway}, if it was top dead on the other stroke, one valve will
be closing as the other one is opening. When they are fully closed, try to rotate the valve with your fingers, if you can, it is not fully closed. Also with the muffler and carb off, as well as the head, again tdc, spray some carb spray in the intake and exhaust ports, and you can see the leakage.

 

[Fish]

Yes, definitely try the old flywheel, then you can rule it out if it doesn't help. Why did you change it again?

 

[Xxtjtheboater95xx]

The flywheel teeth are stripped on part of the flywheel and every time I started it, the teeth would get worse, it's a plastic ring gear. The guy I bought the engine from gave me a new one with aluminum ring gear but I don't know if its the same because I just rushed to get the new one on. It fits and the starter works fine on it so I didn't question it. I can't find a part # on it but its rusty anyway. I don't think it will work though because the teeth may be too worn, maybe I'll be able to pull start it. I do have the old blown engine that I took off the tractor and has the same almost the same model numbers.(below)

Newer engine - 28r707-0148-01
Blown engine - 28r707-1120-e1

The blown one though has a aluminum or steel gear and so does the starter gear pinion gear

But the newer one has a plastic starter pinion which I think is kind of weird.
That flywheel may also be able to be interchangeable as well, so that's why I bring up that engine.

Let me know if I'm confusing you in any way.

 

[Xxtjtheboater95xx]

I will spray the carb cleaner in the intake and exhaust ports, sounds like a good idea for checking leakage.

 

[Fish]

Looks like the same flywheel, but if you swap, you should also swap the gear on the starter. But as far as running, no difference.