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B&S 446777-0165-E1 V-Twin Firing on one cylinder

33K views 49 replies 7 participants last post by  mikeinri 
#1 ·
Hey guys,

Great site. I hope you can help.

I have a B&S 446777-0165-E1 twin cylinder engine. It appears to be running on one cylinder, here are the symptoms:

Has spark to both cylinders (tested by mechanic). Appears to be getting gas to both cylinders (tested by mechanic).

Starts easily and sounds like it's running on both at startup.

Within a few seconds, the sound of the engine changes, appears to run more smoothly.

With both plug wires in place and the engine running, if the "bad" cylinder spark plug wire is removed, nothing changes.

With both plug wires in place and the engine running, if the "good" cylinder spark plug wire is removed, the engine dies.

Mechanic did a compression test. Says that the "bad" cylinder is showing 150 at cranking/startup, within a few seconds drops to 120, then to 60 and stays there.

His suggestion was to replace the engine.

Any better suggestions?

Mike
 
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#2 ·
Mechanic did a compression test. Says that the "bad" cylinder is showing 150 at cranking/startup, within a few seconds drops to 120, then to 60 and stays there.

His suggestion was to replace the engine.
Find another small engine guy and have him look at the valves. You could pull the exhaust/muffler and have a look at the cylinder walls. If scored, replacement may be in your future. If not, my guess would be head gasket or a valve problem.
 
#3 ·
Thanks. After reading another post here, I was thinking about cleaning the carb, and opening the valve covers, inspecting and adjusting the valves to see if that improves anything. What do you think?

BTW, do those compression numbers make any sense? I have the B&S repair manual, but it says B&S doesn't publish compression numbers. It just gives advice to test if the cylinders are behaving equally.

Back up my hard drive? What if it's already against the wall?

Mike
 
#5 ·
Engine and tractor are 2003.

He said the compression on the "good" cylinder is fine, but I don't think he gave me numbers.

No mention of failing coil. Wouldn't that kill the spark (he said it's getting spark, I haven't tested it yet myself).

Not to be overly stupid, but a compression test can really only be done with the engine NOT running, correct?

BTW, other than knowing it's running on one cylinder, it operates just fine. I do use this with a snowblower attachment, so I'd really like both cylinders to be running...

Mike
 
#6 ·
BTW, does anyone know where I can figure out which replacement model will fit if it comes to that?

The B&S site just has the newest specs, no cross-reference list that I can find. The big thing seems to be the "Type" code, which is supposed to indicate PTO, etc. Mine is 0165, what does that mean?

Mike
 
#7 · (Edited)
Did you actually witness the presence of spark, or are you going by what the machanic told you?? Yes, a compression test can only be done by cranking the engine with the ignition disabled.

I'm toying with the notion that a valve may not be closing all the way.... getting "hung" after the engine comes up to temperature. A constant "puffing" noise in the muffler will indicate the exhaust valve and a "popping" noise in the air cleaner indicates an intake valve.

Check for spark and condition of spark plugs.... a plug may look good even though it has failed. Usually when a plug fails it is done for and will not come back to life and exhibit the symptoms your mower is showing.

I still don't think the engine needs replaced..... the least may be a bad coil and the worst could be valve servicing.

I came up with this...ouch!!

http://www.napaonline.com/Search/Results.aspx?Ntt=691060&Ntk=Interchange Number&Nty=1&N=0

Got the part # and did a cross reference. Kinda pricey but less than a new engine!!
 
#9 ·
Thanks guys. I agree, valves do seem to make sense. I also have neglected some routine maintenance this year (oil, filters, plugs are all at least 1-2 years old)...

Mechanic mentioned valves, but thought it was probably cylinders because it had some pressure to start with. Honestly, I don't know how good this guy is, this is the first time I tried him out.

The mechanic didn't do the spark test in front of me, and I haven't pulled the plugs yet myself. I plan to do all of that tomorrow, and I will get a compression tester to help.

I'll start by adjusting the valves and see if that helps. I did notice a sound that almost sounded like backfiring (on the one cylinder that does work), so I probably have valve issues on both sides, most likely a dirty carb as well.

Here's my plan:
Change spark plugs, oil, air and fuel filters.
Clean carb.
Adjust valves (both cylinders).
Test for spark.
Test compression.

BTW, I couldn't get that napaonline link to work.

Just of out curiosity... How do I know what the type number means? Mine is 0165, where did you get the info that 0127 is a direct replacement?

Mike
 
#12 ·
Thanks guys. I agree, valves do seem to make sense. I also have neglected some routine maintenance this year (oil, filters, plugs are all at least 1-2 years old)...

Mechanic mentioned valves, but thought it was probably cylinders because it had some pressure to start with. Honestly, I don't know how good this guy is, this is the first time I tried him out.

The mechanic didn't do the spark test in front of me, and I haven't pulled the plugs yet myself. I plan to do all of that tomorrow, and I will get a compression tester to help.

I'll start by adjusting the valves and see if that helps. I did notice a sound that almost sounded like backfiring (on the one cylinder that does work), so I probably have valve issues on both sides, most likely a dirty carb as well.

Here's my plan:
Change spark plugs, oil, air and fuel filters.
Clean carb.
Adjust valves (both cylinders).
Test for spark.
Test compression.

BTW, I couldn't get that napaonline link to work.

Just of out curiosity... How do I know what the type number means? Mine is 0165, where did you get the info that 0127 is a direct replacement?

Mike
The type number identifies the engine mechanical parts, color of paint, decals, governed speed and Original Equipment Manufacturer. The replacement engine information is from Briggs & Stratton.
 
#10 · (Edited)
I see what you mean about the link... I always check the links and it worked after I posted but does not work now. I will recheck and post if needed.

Just checked link again and it worked:4-dontkno
Could be a problem on their end.

Problem is on their end...retried and got error.
 
#13 ·
That's what's driving me nuts. When I look at the B&S website, I find a nice catalog of replacement engines and their specs, but I can't find a direct cross-reference list to old engines.

So, without pulling the engine out of the tractor, how do I know what size PTO I have (that seems to be the critical piece of info, and 0165, 0127, etc. must be the key to that info).

Mike
 
#16 ·
Right... is that length not critical?

BTW, can't get your new link to work, either. I did go to their main page and searched for my number (446777-0165), but it wasn't found...

Hopefully, my list of items to fix tomorrow will get me going. I'll let you know.

Thanks again.

Mike
 
#17 · (Edited)
OK, here's an update.

FYI, I confirmed with B&S (email through website) the following information for replacing the engine: 446777-0165 replacement is 44Q777-0127, short block is 698172 (K-B was right, above). The 0165 featured the following: The crankshaft on the engine is 3 5/32" in length with a 1" diameter. The end of the crankshaft is tapped 7/16"-20.

Didn't get time to finish much of my list this weekend. Fortunately, the snow that we got Saturday night didn't amount to much on the driveway...

OK, so I tested for spark with a spark plug test light (not the B&S tool, but one that I bought at a local auto parts store). Both cylinders show spark during startup and while the engine was running (not that both cylinders are running).

Removed the spark plugs. The plug in the "good" cylinder looks normal, gap was good (0.030 in). The plug in the "bad" cylinder looked sort of OK, the electrode and insulator looked normal, and the gap was good. However, the base of the housing appeared to be wet, but I can't tell if it's gas or oil (it's black, and a bit gritty looking).

I then switched the plugs (put the one from the "good" cylinder into "bad" and vice-versa). The engine shows exactly the same symptoms, so the problem is definitely not the spark plugs.

I removed the air cleaner, and sprayed some carb cleaner and PB Tune-Up spray into the carb while the engine was running. This caused lots of choking and smoke, but after it cleared, it does sound a little better. This didn't fix the bad cylinder (not that I expected it to).

I also noticed that when the engine is stopped, some small puffs of white smoke come back up through the carb. I'm sure this is not normal, but what would cause that?

This is where I ran out of time. I really don't want to pull the carb apart yet (especially since I don't have a gasket set right now), so what should be my next move? Should I jump right to adjusting the valves?

Mike
 
#18 · (Edited)
I does seem that the valves may need to be looked at.

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3441&body_0$tbKeyword=valve adjustment

See if you can get some useful info from the link.

If the engine has been neglected you may be looking at replacing it...hope not.

Don't know why it didn't come up as a link.. might have to copy and paste it.
 
#19 ·
I don't know if I qualify as "neglecting" the engine. I ususally replace the plugs, oil and filters every year, I know I didn't get to it yet this year. I haven't had the carb apart in several years.

Anyway, I'm going to start with adjusting the valves and see if that helps. If not, I'll pull the heads/valves and carb apart and go from there.

Mike
 
#22 ·
OK guys, here's an update. Finally got to work on this a bit tonight.

The "bad" cylinder is #2 (per the B&S manual). This is on the "driver" side of the tractor, so to speak.

Anyway, I pulled the valve cover off, removed the spark plugs, and turned the flywheel per the smalleng video to adjust the valves. The intake valve was actually too tight, so I adjusted it to 0.004. The exhaust valve was perfect, so I left it alone.

Put it back together (with the air cleaner off), and tried to start it with JUST the #2 spark plug wire in place. To my amazement, it started and ran. I shut it off, reconnected the #1 wire, and started it back up. Then, I pulled the #1 wire off while running, and the engine died as before.

So, I think I've gotten nowhere. I restarted the engine a few times with just #2 (the bad cylinder). It starts and runs (poorly). The throttle "hunts" or "surges" and the engine sounds like it's backfiring sporatically, but frequently. Again, this is all done with the air cleaner removed. Still runs beautifully on #1...

Tried spraying more carb cleaner while it was running, that was no help.

OK, what next? The manual says the following may affect one cylinder, not both:

1. Spark plug and carb adjustment. I know I have spark (used a test light), and (I swapped the plugs, so I know the plugs are both good. Not sure how a carb adjustment could affect just one cylinder on this engine.

2. Leak in spark plug wire. Again, this seems unlikely, as the test light shows good spark.

3. Head gasket.

4. Intake manifold.

5. Valves.

6. Rings.

7. Piston.

8. Cylinder.

So, unless you guys think my problem may be limited to a dirty carb, I think I'm looking at pulling the carb, intake manifold, and head, and at a minimum, cleaning everything and replacing the gaskets. I think a valve job is beyond my capabilites.

Any other ideas???

Mike
 
#23 · (Edited)
Hello mike, let me see if i can help out some. First your compression should be around 150 or so. Its not that important to be lower , due to the decompression being built into the cam shaft. I recently had a 446777/ 21 hp kick my butt, all over a carb. It was one of those non adjustable carbs . I disassembled it several times cleaning and poking around in it trying to find a problem. I came to the conclusion that one of the cylinders was hogging the fuel and a new carb did i fact fix my problem. Those carbs are really finicky and have some strange parts in it. Now about that cylinder that is running at 60 psi. That is not normal. Are you positive that is what is going on? If so a leak down check will tell you were its leaking.

Here is the link to my post of my engine .

http://www.techsupportforum.com/f258/briggs-446777-21hp-backfire-thru-carb-401055.html .

There are 2 videos there to watch,one is my motor backfiring thru the carb and the other is a really good valve adjustment video.
My original problem was a partially wiped lobe on the cam shaft,which is common for that engine. That is easy to check just make sure your rocker arms are all moving equally.
 
#24 · (Edited)
Thanks. I did see your other post, that's the video I used to adjust my valves. That was extremely helpful.

When you say to watch for equal rocker movement, I don't know if I would be able to see that. How obvious would this be, and what's the best method for turning the engine while looking for this?

I am unsure about the compression, I didn't see the guy do the test. I bought a basic compression gauge, can someone walk me through what to do with it? I get the basic idea, but I'm trying to figure out what the mechanic was doing when he saw the pressure drop. Don't these gauges just show the max compression until you relieve the valve on the gauge?

The other thing that concerns me is that there is a visible amount of vapor coming out of the breather tube into the air intake (engine running, air filter off). When the engine stops, a bunch of white smoke comes back up and out of the air intake. I know this is a sign of a bad breather, but it's also a sign of worse things, isn't it?

BTW, when #2 is running (poorly), it's only at WOT. When I turn it down to idle, it backfires and stalls. #2 doesn't run when #1 is also running (the engine actually sounds beautiful with just #1 running)...

I'm sort of at a conundrum here. I really don't want to invert too much money into the tractor, and especially don't want to get in over my head with ripping the engine apart beyond my abilities to get it back together again. The cost of tractors is dramatically lower now than when I bought this one in 2003, so it's harder each year to justify spending $200 here and $200 there anymore (a new engine would probably be a really bad investment).

Thanks guys, I haven't given up on this yet, I want to at least make it to spring (it's snowblowing time), so if there are more ideas, please keep them coming.

Mike
 
#25 ·
Wow, 12-15 inches of snow, went through it with the 42-inch snowblower on just one cylinder, no problem. Wonder how long I've had this problem with no clue it was happening...

Which leads to my next question: If I keep running this engine on one cylinder, will it make the bad cylinder any worse?

BTW, from my original "to-do" list, here's my status:

Change spark plugs, oil, air and fuel filters. DONE
Clean carb. NOT done (I need a gasket kit)
Adjust valves (both cylinders). DONE for #2, I'm not touching #1 right now, it's running beautifully.
Test for spark. DONE (with test light, spark on both sides looks good)
Test compression. NOT done yet, read my question in my last post.

Mike
 
#26 ·
Keep a really close eye on the oil. Running on one cylinder and one not running but still, maybe, getting gas, the protective oil film will be washed away.

Check the level often. Smell it !

BG
 
#27 ·
Gotcha. Gas in oil is bad...

What's the preferred method to clean the carb? I would assume taking it apart and soaking it is best. What's the best cleaner to soak it in?

Here's something scary. I just found a carb gasket kit for under $40, but a new carb is only $140. I would hate to clean the carb, put it back together with the new parts, and then have to throw it away and buy a new carb like madcat had to.

Mike
 
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