Author Topic: Smoking trait of the petteroid, can it be reduced/eliminated?  (Read 24827 times)

sid

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #15 on: June 16, 2006, 03:50:04 AM »
most of my petters smoke a little on start up and for the first few seconds but clear up very quickly// you do have have a problem//like everyone else it would be just a guss// do you have very much run time on it//at least the mosquitos are under control//sid
15 hp fairbanks morris1932/1923 meadows mill
8 hp stover 1923
8 hp lg lister
1932 c.s bell hammer mill
4 hp witte 1917
5 hp des jardin 1926
3 hp mini petters
2hp hercules 1924
1 1/2 briggs.etc

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #16 on: June 16, 2006, 04:28:08 AM »
Hi Dutchman,
At first mine smoked like yours but now it's much less with the modified piston... I'm not sold on a valve problem...  sounds to me like the rack / governor  is hunting a bit... and it is likely wet stacking because of the lack of a load.. you may need to load it to burn the fuel / oil out the the exhaust.. ... I think it will run better when you load the engine.. 

mkdutchman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #17 on: June 16, 2006, 01:40:04 PM »
yeah, there is a definite "blown valve" sound coming out of it, as you say, bent or sticky, broken spring, bent pushrod, lots of possibilities there, but it is missing a lot of power strokes, which could also be down to the pump / governor, but that blowy valve sound is where I'd start.
Hmmm, the "blown valve" idea is foreign to me, what exactly is that? And how do you correct it? And yes, you're right on the power stroke missing, one time when I had the injector out I noticed that at low throttle speeds the injector shoots only every other time and at even lower speeds every third time. Haven't been able to get to the bottom of that yet.

And seating the rings.....I think what we'll do right now is install the motor and run it under load for a while, just to see if it make any difference in the smoke.

sounds to me like the rack / governor  is hunting a bit... and it is likely wet stacking because of the lack of a load.. 
What is wet stacking?

I sure do appreciate all the  helpfulness and suggestions.

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #18 on: June 16, 2006, 02:35:47 PM »
Wet stacking is when the engine is not burning the fuel / oil to the point that there is wetness of the exhaust pipe. It is usually found on engines that run high RPM and no or little load..like a generator.. The Detriot 2 strokes are known for this..  diesel exhaust increases in response to the load on the engine.. as for the injector firing every other time... why don't you mark the flywheel with TDC and crank the engine... the injector should "fire" every other time the piston comes to the top of the stroke..

mkdutchman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #19 on: June 16, 2006, 03:00:25 PM »
.. as for the injector firing every other time... why don't you mark the flywheel with TDC and crank the engine... the injector should "fire" every other time the piston comes to the top of the stroke..

I already did that, (actually, I used the camshaft) and I know the injector should fire, every time the crank handle comes around, but it doesn't, only every other time, and at lower throttling every third time, will have to check for air I guess......

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #20 on: June 16, 2006, 03:54:04 PM »
Ok, if it's not firing every time the crank handle, which is on the camshaft on this engine, comes around, then that explains the origin of the smoke:  unburned fuel.  The cam's right and the tappet clearance is OK from an earlier post. 

And you checked that the injector spray is fine, with no drips.  With the injector removed from the cylinder head does the injector spray reliably every time the crank handle comes around?

The "blown valve" thingie means that you might have either the intake or exhaust valve sticking in its guide.  It might be bent, out of tolerance, or running in a warped valve guide.  The valve also might not be seating properly, which is consistent with the behavior you describe (running ok at high speed but missing at low speed).  To be sure you'd have to lift the head off and remove the valves and possibly the guides. 

This is a puzzle

Halfnuts

« Last Edit: June 16, 2006, 03:57:12 PM by Halfnuts »

GuyFawkes

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #21 on: June 16, 2006, 04:57:08 PM »
yeah, there is a definite "blown valve" sound coming out of it, as you say, bent or sticky, broken spring, bent pushrod, lots of possibilities there, but it is missing a lot of power strokes, which could also be down to the pump / governor, but that blowy valve sound is where I'd start.
Hmmm, the "blown valve" idea is foreign to me, what exactly is that? And how do you correct it?

stick your ear next to an inlet or exhaust tract, that "tanking" / "pop down the end of a sewer pipe" sound is a valve blowing, hard to tell from a video, but has that definite ring to it.

basically means the valve isn't seating and sealing, causes include

worn / buggered seats or valves
broken valve springs or weak springs
bent valve
"Pick up" on valve stem
tappets too tight and close when motor warms up
bent guide
"pick up" inside guide
riveted upper or lower guide throat
bent pushrods
worn or incorrectly set up rockers and rocker shaft

basically do a compression test, better still, do ten in a row
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ronsmith

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #22 on: June 16, 2006, 07:35:12 PM »
my petter is doing the popping down inside the engine, but only after it has run 10 min. or so. It is smoking grey smoke heavily. The sound is like a...pom..pom..pom sound down inside. And the poms are not on every stroke more intermittant.

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #23 on: June 16, 2006, 08:06:59 PM »
Guy and I are in agreement about the valves being the source of the funny sound.  Something's wrong there.  Time to tear it apart and see what's what.

Halfnuts

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #24 on: June 16, 2006, 10:01:09 PM »
Not sure about the Pom Pom's but if the injector isn'tsquirting fuel everytime the cam makes a revolution you need to check into that... most likely a defective IP.. I still don't think you have a valve problem.. If you did you would be leaking compression...

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #25 on: June 16, 2006, 10:41:26 PM »
Mr. Wagon (I can't bring myself to call someone "Fatty"),

If you watch the video you'll hear a miss, then immediately after, see a big puff of smoke, so I think the injector is firing, but perhaps one of the valves isn't opening or closing or sealing on one or more cycles, and on the next successful combustion cycle, the fuel is burned.  If the injector simply weren't firing that wouldn't cause a puff of white-ish smoke. 

If he's got a badly seating valve that seats intermittently, that would explain the engine's behavior.  As for the injector firing, he's indicated it is firing when he cranks it over.  No way to crank it over at 1500 rpm to see how consistent it is, though.

Halfnuts

europachris

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #26 on: June 17, 2006, 02:07:07 AM »
One thing to check would be the piston rings.  Maybe one could be broken (or missing) and allowing loss of compression and/or lube oil coming up into the combustion chamber?

Something else - my Changfa 185 acted quite a bit like this when I first started it up.  Two things I noticed - the injector pump feed line from the fuel tank wasn't completely bled of air yet so the fuel going to the pump was getting pretty foamed up from all the pulsing action.  I also had the oil bath air filter a bit overfilled (and with too light of oil) so the engine was inhaling some extra oil there and blowing it out as blue smoke.

I'd take a real hard look for any air bubbles (or air leaks) from the fuel tank, fuel filter, and injection pump supply lines.  The injector won't fire every time if half the fuel coming to the injection pump is full of air bubbles.  Could even be a restriction in a line somewhere.


Chris

ronsmith

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #27 on: June 17, 2006, 02:57:25 AM »
I removed the rocker box, checked thr pushrods and reinstalled the rocker box. Then I reset my valve tension. It did not seem to be too far out. I set them to 15 on intake and 20 on exhaust with feeler gauge. THEN I removed about 3' of extension pipe from the exhaust port to my water barrel smoke filter. I screwed the muffler back on in its original spot and fired it up. It blew hot carbon sparks out for 3 or 4 minutes aand smoked grey, then when most of the carbon blew out the smoke turned blue and it smoked about like the petter in the video clip, which is a 75 percent imporvment over what I had.

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #28 on: June 17, 2006, 05:12:51 AM »
That's OK if I can call you halfnuts... then you can call me fatty... My Petter smoked a lot  but it's much better after the piston mod... 

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #29 on: June 17, 2006, 06:03:17 AM »
Yeah, but there's something wrong with the engine in question.  The sound isn't right and the pattern of belching smoke is trying to telll us something.  I'm not accustomed to hearing a diesel engine miss like that.  Sounds like a motorcycle engine with the spark too far advanced or a lawnmower engine with a stuck choke.  Smokes like one, too, by the way.  Everyone is weighing in with their ideas which is good.  Only thing to do now is to track it down.  An air leak into the fuel line is a possibility, however when stopped, you'd then expect fuel to leak out and make a mess that could be traced back to the leak.  If it's just a few trapped bubbles remaining in the fuel line getting whipped around by the fuel injection pump, that might account for the rough running but it doesn't explain the smoke.  I really hate puzzles.  Diagnosing this from afar is like playing "20 Questions" with my kids.  I be thankful they've grown out of that.

Halfnuts