Export thread

Ariens yt12 with replacement engine B&S 28r707

#1

X

Xxtjtheboater95xx

Hi guys, been reading these forums for a while now for your great help. This time though, I think I have a unique problem but it could just be a carb problem.

Here's the story

I have been using this mower over the summer, I bought it with a blown engine for a great price with multiple attachments including a snowblower on it right now. I went to start it the other day when we had a big snow storm and it wouldn't start right away and the cranking was pretty slow so I thought it was the battery. I cranked it a bunch of times and the flywheel teeth were a little stripped in one spot but after all those cranks it seemed to strip more and more of the teeth so I had an extra flywheel with a good ring gear. And it did start but I noticed afterward that the starter pinion gear was stripped now, and I think this is because the starter froze in the up position from the really cold weather and it rained and then froze during this whole process.

I also had an extra pinion gear and replaced that last night so that's all good. But still when I try to start it, it will start with a few cranks but only when I disconnect the transmission from the engine with a knob and this allows it to start because it is not spinning all those extra belts.

Still when it does start, it doesn't rev to full speed like it normally does I'm pretty sure because of the sound.

It was last night I started it again with the new flywheel and starter gear and I saw the muffler inside and it was red hot and so I shut it down. It has enough oil and is sitting on a level surface. The redness might be normal, but I just haven't seen it run before at night so I didn't want to wreck it and I just know it wasn't running right in the first place, thinking it might just not be getting enough fuel to run faster and I would think it needs a carb cleaning. But it worked well when it was warm out and only now having trouble. As I was thinking this, I hoped the new flywheel didn't change anything, I mean I didn't weigh them but they look exactly the same and they are both pretty darn heavy.

Ask me any questions you may have. Thank you for your help. I tried to give as much information as possible but I may have missed something.


#2

Fish

Fish

Remove the flywheel nut and make sure that the key is not partially sheared, it could be the cause of the hot muffler, you may not have torqued the nut down tight enough.


#3

X

Xxtjtheboater95xx

I remember putting the key in and hammered it down about a quarter inch below the surface of the flywheel and tightening the nut down as good as I possibly could do on my own with a crowbar and a torque wrench. By sheared, do you mean like the corners of the key dented in or like what would make a key shear? Am I missing something here?
Sorry :confused2:


#4

X

Xxtjtheboater95xx

Flywheel key is in the right place, it'll run fine but after running for only about 30 seconds to a minute, the muffler will glow red hot as stated before, this is my biggest concern right now.

Oh and it eventually puts out a blue flame continuously after more than a min but I shut it down after that because I think I'm going to break something.


#5

X

Xxtjtheboater95xx

Opened the cylinder head today and the top of the piston has some good carbon built up on it and so does the intake valve but the exhaust valve has a white coating of some sort on it. The valves, I'm pretty sure are seating nice and tight with no wiggle.

What do I check now for why the muffler is getting so red hot and the engine isn't staying started for too long.
Btw when I move the throttle lever, it doesn't seem to make much of a difference moving it slower or faster(but it does need to be at a relatively high throttle position for it even to start) best I'm not sure if its because its just too cold out.


#6

Fish

Fish

You need to check your valve clearances, you will likely find the exhaust valve probably doesn't have any gap, and the exhaust cold with the piston at top dead center should be between .009" and .011", intake between .005" and .007"


#7

X

Xxtjtheboater95xx

Finally was able to check the valve clearances, and they are within spec.had to take carb off for that so I cleaned the carb again and it's clean. I try to start it and it'll start when I choke it and will run for a few seconds and then shuts down, if I keep pushing the choke in and out it'll keep running but I'm thinking the guy gave me the wrong flywheel, but he knew what engine I bought from him. Anyway it fits but I don't know whether a wrong flywheel will cause the engine not to run right. Or if I should look for something else instead of taking the damn flywheel of again.


#8

briggs

briggs

Xxtjtheboater95xx said:
Finally was able to check the valve clearances, and they are within spec.had to take carb off for that so I cleaned the carb again and it's clean. I try to start it and it'll start when I choke it and will run for a few seconds and then shuts down, if I keep pushing the choke in and out it'll keep running but I'm thinking the guy gave me the wrong flywheel, but he knew what engine I bought from him. Anyway it fits but I don't know whether a wrong flywheel will cause the engine not to run right. Or if I should look for something else instead of taking the damn flywheel of again.
Click to expand...


take the carb of again soak it in a mix of gas and sea foam of night then blow it out with compressed air make sure u get all the ports etc


#9

exotion

exotion

briggs said:
take the carb of again soak it in a mix of gas and sea foam of night then blow it out with compressed air make sure u get all the ports etc
Click to expand...

If it starts on choke that means it wants fuel because something is partially slowing the flow of gas as soon as you take it off choke you create a bigger mix of air and gas but your Carb is starving for fuel I agree you need a better way to clean it if I clean a carb the first time I use compressed air and carb cleaner the second time I let soak fully submerged in seafoam I make sure I twist it around to get all air bubbles out the next day I take it out use can of carb cleaner and a lot of compressed air. Maybe a new needle and seat and o ring also don't forgt new gaskets between carb and engine


#10

briggs

briggs

exotion said:
If it starts on choke that means it wants fuel because something is partially slowing the flow of gas as soon as you take it off choke you create a bigger mix of air and gas but your Carb is starving for fuel I agree you need a better way to clean it if I clean a carb the first time I use compressed air and carb cleaner the second time I let soak fully submerged in seafoam I make sure I twist it around to get all air bubbles out the next day I take it out use can of carb cleaner and a lot of compressed air. Maybe a new needle and seat and o ring also don't forgt new gaskets between carb and engine
Click to expand...


i agree:thumbsup:


#11

Fish

Fish

Sounds like the exhaust valve is leaking badly, a complete valve job is probably needed. With the plug back in, rotate the flywheel backward to check the compression.
You should reach a point that the flywheel will stop, and rebound back, with some bounce, it is a quick way to check an engine's compression.


#12

X

Xxtjtheboater95xx

Do you mean the valves need to be lapped? I want to say that the engine makes a clickity clack sound when it does run and I'm pretty sure that's not what it's supposed to sound like. But not like a knocking sound.its hard to explain, I can post a video tomorrow


#13

X

Xxtjtheboater95xx


Take a look and listen to it and see what you you think. ask me anything.

I put a newer carb on it and had it clean just like the last one


#14

Fish

Fish

Xxtjtheboater95xx said:

Take a look and listen to it and see what you you think. ask me anything.

I put a newer carb on it and had it clean just like the last one
Click to expand...

Likely a loose valve seat!!! Sounds like you need a good neighbor!!!!


#15

X

Xxtjtheboater95xx


Another quick video

Would this also indicate a loose valve seat? Some sort of visible air coming out of the carb.

And if there was a loose valve seat, would I be getting any compression?
I think I should get a gauge to test the exact psi.

.


#16

pugaltitude

pugaltitude

Have you tried a new head gasket?
Air coming back through carb is usually due to head gasket blown between cylinder and valve chest.


#17

Fish

Fish

Yeah, you need to have someone go through the valve system, and just lapping the valves won't cut it. That intake seat may be loose as well, and if that needs to be re-peened in, the seats and valves definitely need re-cut.

For those that are not sure, this is not an OHV model.


#18

Fish

Fish

I dug out an old block with valves, I'll just pull out the intake for this pictorial....

Attachments







#19

Fish

Fish

The exhaust valve is white and powdery from the heat of a leaking valve..


#20

Fish

Fish

The Neway seat cutter cuts the seat at an angle that is 1 degree off from the valve face, that difference is where the seal is, just lapping, just smears the contact over a huge area and valve leakage is certain, so the repair is poor and will not last long.....

Attachments





#21

Fish

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.....

Attachments





#22

Fish

Fish

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

Attachments







#23

Fish

Fish

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

Attachments







#24

Fish

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!!!!!!


#25

X

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.


#26

Fish

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.


#27

Fish

Fish

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


#28

X

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.


#29

X

Xxtjtheboater95xx

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


#30

Fish

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.


#31

X

Xxtjtheboater95xx

Right, I have three flywheels though(1 from blown engine, 1 from newer engine, 1 from the guy that i bought the newer engine from since i told him some of the plastic teeth were already worn). I will try the 1 frame the blown engine on the newer engine. The one I have on the newer engine that I'm having trouble with is the replacement one the guy gave me but who knows if its the right one.

This was just for clarification*


#32

X

Xxtjtheboater95xx

Also, I did what you said, taking the carb and muffler off and spraying carb cleaner in those ports and didn't see any leakage out from the valve seat area, so I'm pretty sure they are fine.

FYI when I took the head off again today after cleaning everything well yesterday, I noticed the exhaust valve was white again but I researched this and seemed this is usually normal since the hottest air is going out through the exhaust anyway.


#33

Fish

Fish

What are the valve clearances set at?


#34

X

Xxtjtheboater95xx

Last time I checked they were

Intake: .006

Exhaust: .009

So that's within spec


#35

Fish

Fish

So do you have the flywheel that came on the engine you have now? if so, put that back on just to see.


#36

X

Xxtjtheboater95xx

Flywheel key was sheared. Haven't been able to try it now since I need a new key.

But I'm wondering how I can prevent this from happening the next time I put the flywheel on, any suggestions.?

Thanks.


#37

X

Xxtjtheboater95xx

I was reluctant to think it could have possibly been the flywheel key because I just recently put it on, even though I looked before, it was a brief look and could clearly see it with good light, and since I resorted to taking the flywheel off anyway.


#38

Fish

Fish

Fish said:
Remove the flywheel nut and make sure that the key is not partially sheared, it could be the cause of the hot muffler, you may not have torqued the nut down tight enough.
Click to expand...

We went the long way around the barn, eh?

You didn't torque the flywheel nut tight enough, I use an impact wrench myself.

On the top of the flywheel, there are two threaded holes, you could thread in two long bolts and use that to lock the flywheel.


#39

X

Xxtjtheboater95xx

Yeah, I didn't realize how much torque played into keeping the key from shearing, I knew that happens but I wasn't sure what caused the key to shear.

now I know

Sorry for the trouble.image.jpg


#40

Fish

Fish

No trouble, it got me to break out my valve cutters!!! Hopefully you are ready to get that thing going!


#41

X

Xxtjtheboater95xx

Went to the nearest lawn mower parts store and got a new flywheel key(in the middle of a snowstorm no less), started up the first try and runs like a champ!!!

You really can't tell that the flywheel key is sheared until you take the flywheel off.

Lesson learned.

Luckily everything works for this huge snowstorm here in the northeast

I was actually installing the flywheel when we already had about 5 inches of snow on the ground

I'm still surprised when I put the flywheel on the first time that the key would have sheared that quickly, meaning it wouldn't have run ok the first time or something.


#42

C

chockkicker

Xxtjtheboater95xx said:
Hi guys, been reading these forums for a while now for your great help. This time though, I think I have a unique problem but it could just be a carb problem.

Here's the story

I have been using this mower over the summer, I bought it with a blown engine for a great price with multiple attachments including a snowblower on it right now. I went to start it the other day when we had a big snow storm and it wouldn't start right away and the cranking was pretty slow so I thought it was the battery. I cranked it a bunch of times and the flywheel teeth were a little stripped in one spot but after all those cranks it seemed to strip more and more of the teeth so I had an extra flywheel with a good ring gear. And it did start but I noticed afterward that the starter pinion gear was stripped now, and I think this is because the starter froze in the up position from the really cold weather and it rained and then froze during this whole process.

I also had an extra pinion gear and replaced that last night so that's all good. But still when I try to start it, it will start with a few cranks but only when I disconnect the transmission from the engine with a knob and this allows it to start because it is not spinning all those extra belts.

Still when it does start, it doesn't rev to full speed like it normally does I'm pretty sure because of the sound.

It was last night I started it again with the new flywheel and starter gear and I saw the muffler inside and it was red hot and so I shut it down. It has enough oil and is sitting on a level surface. The redness might be normal, but I just haven't seen it run before at night so I didn't want to wreck it and I just know it wasn't running right in the first place, thinking it might just not be getting enough fuel to run faster and I would think it needs a carb cleaning. But it worked well when it was warm out and only now having trouble. As I was thinking this, I hoped the new flywheel didn't change anything, I mean I didn't weigh them but they look exactly the same and they are both pretty darn heavy.

Ask me any questions you may have. Thank you for your help. I tried to give as much information as possible but I may have missed something.
Click to expand...

Running to lean a fuel air mixture will cause hot exhaust


#43

L

lfredg

Xxtjtheboater95xx said:
Finally was able to check the valve clearances, and they are within spec.had to take carb off for that so I cleaned the carb again and it's clean. I try to start it and it'll start when I choke it and will run for a few seconds and then shuts down, if I keep pushing the choke in and out it'll keep running but I'm thinking the guy gave me the wrong flywheel, but he knew what engine I bought from him. Anyway it fits but I don't know whether a wrong flywheel will cause the engine not to run right. Or if I should look for something else instead of taking the damn flywheel of again.
Click to expand...

when you checked valve clearance were you on tdc of compression stroke it still sounds like your valves are out of adjustment and that happens if set on wrong stroke


#44

M

maz94

briggs said:
take the carb of again soak it in a mix of gas and sea foam of night then blow it out with compressed air make sure u get all the ports etc
Click to expand...

If you cant fix it with a HAMMER or DUCT TAPE it in an electrical problem Sorry just trying to lighting the load. I also think it is a valve


#45

M

maz94

Xxtjtheboater95xx said:
Finally was able to check the valve clearances, and they are within spec.had to take carb off for that so I cleaned the carb again and it's clean. I try to start it and it'll start when I choke it and will run for a few seconds and then shuts down, if I keep pushing the choke in and out it'll keep running but I'm thinking the guy gave me the wrong flywheel, but he knew what engine I bought from him. Anyway it fits but I don't know whether a wrong flywheel will cause the engine not to run right. Or if I should look for something else instead of taking the damn flywheel of again.
Click to expand...

First I think if it was the wrong flywheel it would kick back and not start at all, it sounds like more of a fuel problem. Is there a fuel filter, if so it may be clogged, if it runs for a short time could be clogged vents in the gas cap. Check the vent holes in the cap. Check gaskets, Make sure they are not sucking air in. Soaking carb doesn't say it is cleaned out, it could have a tiny piece of debris in the main jet. Try the easy things first Cap, Filter or carb loose. I hope this helped Good Luck Maz94]


#46

Fish

Fish

Xxtjtheboater95xx said:
Went to the nearest lawn mower parts store and got a new flywheel key(in the middle of a snowstorm no less), started up the first try and runs like a champ!!!

.
Click to expand...

He said it was fixed.


Footer Links 1

Top