Vanguard 16 hp issues

Tony R

New member
For the past few days l have been having issues with a 16 hp vanguard.
Typically it runs perfect for about 45 minutes, then starts bogging, low on power and I would guess 15% less rpm. This is running 8gpm pumps building washing low pressure. It drops more rpm if using pressure tip. It will run like that for up to another 15-30 minutes (sounds bad. I though maybe it had a really bad miss). I removed the plug wire from #1 cylinder and started it and it ran. Removed #2 plug wire and it started and ran equal. If I keep running the engine with both wires on it will finally bog enough to die. If I shut it off for an hour it will run fine for a while again. It's been warm 85-95.
also the engine has 2100 hours

it has me stumped because I was not able to narrow it down to 1 cylinder. Any ideas??
 
Troubleshooting a V-twin engine which dies when hot.

thin oil, or oil diluted with gasoline from a leaky float bowl can allow the engine to overheat,
.. but usually leads to a complete piston-seize.

an ignition coil can fail in the otherwise "normal" temperature range.

there's a diode between the ignition coils that can fail,

if the air filter is partially plugged.. the ignition fouls out, but usually in a few minutes or less, not after 45.

at a certain age, the compression goes away with the wear on piston rings..
and as the engine gets warmer, the oil is less of a sealant against the rings, compression drops more, and horsepower drops.. engine craps out.
but, at this stage.. you have already seen hard starting for a while.


Whenever troubleshooting an engine.. take the air filter off first..
if that is the problem, you will notice an immediate difference.
If it is a contributing factor, you will find out later, but keep it out of the rest of the troubleshooting.
..you might see fuel dancing up out of the carb, indicating a bad intake valve.
.. that can be an "after-warm-up" symptom too.

the next easiest thing to check is the oil, and low oils sensor..
if the oil isn't low, or smells contaminated with gasoline, disconnect the low-oil sensor wire,
..and leave it off, for the rest of the troubleshooting, as it can be a contributing factor.. like it fails after it gets hot.

next.. get a spark plug wrench, and inspect the spark plugs.. closely.. color, stains, gap, check for cracks,
check the plug wire for cracks, abrasions, and "carbon tracks" from arcing.
..that failure gets worse with working temp too.. hot air is less dense, and allows HV arcing easier.

Now that's a lot of troubleshooting in 5 minutes or less. Eh?
come to my Troubleshooting and BulletProofing Class
 
I have had a couple of customers over the years have something very similar happen to them....in particular with Briggs, vibration causes the choke pull to slowly pull out and kill the engine over a period of time. Not saying that is the problem as several things can cause similar issues as Jerry said, just the only one I didn't see mentioned. Good luck!
 
Lol. That is a good tip. There has been a bungee cord cord keeping the choke in on this engine for the last 1000 hours. I definitely did check that. One spark plug had a little darkness on the insulator and I could not get it to repeat issues at home without air filter. I put new plugs in and new air filter. Ran fine for 2 days. Then today it crapped out right before lunch. Ran fine for 3 hours after lunch.
 
Have had the choke problem numerous times. Scott Stone gave me some good advice to just big some new clips and have them on hand. The just wear out and only take a minute to replace.

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Scott Stone is an idiot and doesn't know anything. I don't even know why you would listen to a guy that is barely making it by... Now, if he had a viable business, he would not have work every day and brag about it. I don't know why anyone listens to that fool.
 
Where do the clips go? Any pics?
 
It's just the little clip up at the actually pull ring on the choke, its held down with a single screw seems like, usually I take it off, bend it a little and replace it. Sometimes that doesn't always work, in which case you can get a clip, or a bungee cord!
 
Scott Stone is an idiot and doesn't know anything. I don't even know why you would listen to a guy that is barely making it by... Now, if he had a viable business, he would not have work every day and brag about it. I don't know why anyone listens to that fool.

Yeah, he isn't too bright, but he was smart enough to know that I was wasting three times as much time trying to bend them than it took to replace them!

Even a broken clock is right twice a day.

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Scott Stone is an idiot and doesn't know anything. I don't even know why you would listen to a guy that is barely making it by... Now, if he had a viable business, he would not have work every day and brag about it. I don't know why anyone listens to that fool.

Scott Don't Be so hard on yourself, it will be ok.
 
Scott Stone is an idiot and doesn't know anything. I don't even know why you would listen to a guy that is barely making it by... Now, if he had a viable business, he would not have work every day and brag about it. I don't know why anyone listens to that fool.

keep talking like that and offending yourself and you could get baned here to buddy...
 
keep talking like that and offending yourself and you could get baned here to buddy...

Once you soar past being a 25%er you are allowed to be eccentric.

Sent from my DROID RAZR HD using Tapatalk 2
 
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