Hi,

Many years ago, we sold a blower to a local "Putt putt" golf course. We recommended optimal at that time. The mix was 100 - 1.

They returned showing us that oil was coming out of the exhaust and dripping on the outdoor carpet of the golf course. We called the Echo warehouse in Texas (Texas Outdoor Power Equipment). They contacted echo techs who had the golf people lean the mix more (I think 150 to 1 optimal).

I AM NOT RECOMMENDING THIS, BUT I AM RECOMMENDING THAT YOU HAVE YOUR DEALER CALL ECHO TECHS FOR ADVISE.

If it were mine, I would put up with the smoke and probably run it on a richer mix than recommended. I am a believer that a rich mixture extends the life of my motors, at least in the weather and elevation I experience.

Good luck,
echoman

 

Hi Echoman...Thanks for your reply. I agree that smoke on a two stroke is a good thing. I was just curious why the other two Echo tools did not smoke with the same fuel mix. Could it be that it becomes more noticeable on a larger displacement engine ( 21.2 cc vs. 44 cc)?

This smoking only came to my attention last week. I normally blow out my garage with the hand held PB-200. But this time, I had the 403 out and decided to blow out the garage with it. Within a minute the smoke detector picked up the smoke and activated the fire alarm. My wife came out and asked what was going on and I told her I did not have a clue. I thought perhaps the alarm had malfunctioned. She said that it was probably from the smoke that the 403 puts out. Honestly, I never knew it smoked because the exhaust exits to the rear. Needless to say, the alarm company had already dispatched the fire department

If I had to guess, it seems like the choke richens the fuel/air mixture too much
to the point that it always stalls out before I can slide the choke off. When that happens, fuel/ oil mixture gets sprayed into the muffler. Then when I pull the recoil a second time, with choke off, it fires up and then proceeds to burn off the excess mixture in the muffler. This is the only two stroke that I have ever had that always fires on the pull with the choke on when it is cold. All the others take 3-5 pulls to fire, but with those, I can slide the choke off and keep them running.

 

If I had to guess, it seems like the choke richens the fuel/air mixture too much
to the point that it always stalls out before I can slide the choke off. When that happens, fuel/ oil mixture gets sprayed into the muffler. Then when I pull the recoil a second time, with choke off, it fires up and then proceeds to burn off the excess mixture in the muffler

Hi,

First, this is all speculation.

I totally agree with your assessment on excess fuel since it chokes well. I also have some other thoughts.

I tend to rationalize everything so that it makes sense to me. With the larger motors on blowers that smoke when the same size motor does not smoke on a chainsaw, I believe it has to do with the constant velocity of the blower relative to the constant change of rpm on the chainsaw motor. I have no proof and can't even speculate on why it should be that way. The only hint I have is that Echo techs told us that the "putt putt" blower could use 150 to 1 because it was constant velocity.

So, go figure. Hope this helps in some way.

echoman

 

What you describe is typical of 2 strokes engines.
The main cause of the smoke is the larger displacement of the blower engine.
When you shut it down, the gas inside the engine crankcase evaporates leaving a film of oil over the internal parts (which is good). When you start the engine after cool down, the "new" mix "washes" the oil film making the mix going in the cylinder very rich in oil thus the smoke.
The second cause is the oil you are using. When the engine is not at operating temperature, the oil doesn't fully burn and create the smoke you see (and carbon up the engine).
I recommend you to use Amsoil ASE at 80:1, it will save you money and eliminate the smoke problem.
Regarding the starting procedure, what you describe is typical as well.
When cold, both my PAS-265 start in three pulls and my PB-755 starts in two.
To start my PAS-265, I put the choke on, hold the trigger full gas and pull twice (engine chuckles on second pull). I then remove the choke and pull once with the trigger full gas. Engine starts and I can put it to work right away (no warm up needed since E3 spark plugs).
On the PB-755, I put the choke on and pull once with throttle at idle (no sputter). I remove the choke and pull once again. Engine starts and I can put it to work right away as well.

 

Hi,

Thanks Happy Frog. Excellent post.

When I made my first post, I was sure I knew everything. I have learned more since then than in the prior 30 years.

You and many other knowledgeable people on this forum are responsible for that.

So, thanks again
echoman

 

Hi Echoman & Happy Frog...Thank you both for the great information. That is what I love about a site like this, you can gain a lifetime of information in just a few minutes!

Happy Frog...your theory of the cylinder being oil coated at shut down makes a lot of sense. I had never thought about that, but with those engines shutting down while still turning 2,300 to 2,500 rpms (at idle), the piston would still be sucking raw fuel into the cylinder and even exhausting it into the muffler. Then when it is restarted while cold, the engine and muffler heat up and begin to burn off that excess mixture that was previously deposited.

It sounds like every engine has it's own starting quirks. This PB-403 always amazes me because cold, on the first pull with choke engaged, it will fire before the rope is half way out. But, before I can slide the choke off, it cuts out. But it will always re-fire on the second pull with the choke off. I have tried to partially choke it when it is cold, but it only wants to start on full choke. If has a mind of it's own...

Thanks again for the great info...

 

Within a minute the smoke detector picked up the smoke and activated the fire alarm. My wife came out and asked what was going on and I told her I did not have a clue. I thought perhaps the alarm had malfunctioned. She said that it was probably from the smoke that the 403 puts out. Honestly, I never knew it smoked because the exhaust exits to the rear. Needless to say, the alarm company had already dispatched the fire department

Bwaa ha ha, I'd have paid good money to see that

Seriously though I'm pleased that the collective pool of knowledge that is Lawn Site has answered your question. These guys never cease to amaze me with their talent.
Good luck Phil

=

 

Happy Frog...your theory of the cylinder being oil coated at shut down makes a lot of sense. I had never thought about that, but with those engines shutting down while still turning 2,300 to 2,500 rpms (at idle), the piston would still be sucking raw fuel into the cylinder and even exhausting it into the muffler. Then when it is restarted while cold, the engine and muffler heat up and begin to burn off that excess mixture that was previously deposited.

Actually, on a 2 stroke engine the mix goes through the crankcase before reaching the cylinder; coating everything with a film of oil (this is how the oil in the mix lubricate the engine). Never mind the cylinder, the extra oil burnt at start up comes from the crank case...

 

Actually, on a 2 stroke engine the mix goes through the crankcase before reaching the cylinder; coating everything with a film of oil (this is how the oil in the mix lubricate the engine). Never mind the cylinder, the extra oil burnt at start up comes from the crank case...

Thank you, Happy Frog......That makes perfect sense.

Now I just have to remember to never take the 403 into the garage just after a cold start up. I am sure our fire department will appreciate it as well!

Phil G...I am glad that I could put a smile on your face. It was quite embarrassing when four engines pulled up in the driveway!

 

Thank you, Happy Frog......That makes perfect sense.

Now I just have to remember to never take the 403 into the garage just after a cold start up. I am sure our fire department will appreciate it as well!

Phil G...I am glad that I could put a smile on your face. It was quite embarrassing when four engines pulled up in the driveway!

Just a thought, when you've finished using the blower let it idle for 15 to 20 seconds so that when you kill the engine the it should stop quicker (drawing in less fuel) than if you killed it with the engine at high revs. Or am I just being a dumb arse?

atb Phil

 

Is it just me or do ya'll see this scene written into a comedy. Thanks for the visual. hahaha

 

Just a thought, when you've finished using the blower let it idle for 15 to 20 seconds so that when you kill the engine the it should stop quicker (drawing in less fuel) than if you killed it with the engine at high revs. Or am I just being a dumb arse?

atb Phil

Actually, Phil, it makes perfect sense. I will give it a try. Normally when I shut it down I am running it faster than idle. Good thought!

 

Is it just me or do ya'll see this scene written into a comedy. Thanks for the visual. hahaha

Yeah...I think that if I had this scenario on video, it would have been a hit. I am only grateful that the wife was home because I did not hear the alarm go off with the blower running. I can only imagine the look I would have had on my face when the engines pulled up with me not having a clue.

 

I’ve had my share of embarrassing moments, and I hope this soothes yours.

I had an auto parts store in 1973. It was in Comanche Texas and a 25 mile drive to a warehouse in Brownwood on a four lane divided highway which had plenty of traffic.

My wife, two young children, and me driving our 1965 white Chevy impala headed toward Brownwood. Along the way, I stopped and popped the hood for some reason. While doing whatever I did, I got both hands oily. The car being white would show the oil stains if I closed the hood with my dirty hands, so, I closed it with my forearms. The hood only half latched. I turned around and sat on it to close it completely.

Now anyone familiar with a 1965 Impala knows the hood does not come all the way to the front and wrap over, rather it comes within 3 inches of the front and closes flush.

It caught both cheeks of my a$$. I was on my tiptoes and it hurt. The hood release was on the center front which was between my legs. As high as my toes would lift me and as long as my arms weren’t, I could not reach the latch. Cars were whizzing by, me sitting on the front of the car (on tiptoes), my hands between my legs with this worried look on my face.

I turned for help as I faced my wife and children. They looked somewhat puzzled since I barely twisted my body (pain) and tried to shout over the traffic. I can remember motioning with my hands to the areas of distress and solution. My wife and then my children tilted their heads like a dog will when puzzled. Then, it hit them. They understood. I could not hear the laughter in the car, but I could see it.

Finally, she got out, put her hands between my legs and released me.

So, maybe you will feel better now. Hahaha

echoman

 

So, maybe you will feel better now. Hahaha

echoman

Ok...That did the trick. Now I don't feel quite so bad. Can't imagine how much that hurt...Ouch!

 

Just for the sake of discussion, I put a new carburetor kit in the PB-403 to see if it would make any difference with the cold start up smoking. I made sure that the needle lever setting was exact. Bottom line...it made no difference at all. So, I am now convinced that Happy Frog's theory of the oil coating the crankcase on shut down and then burning off on cold start is right on!

 

Phil G...I am glad that I could put a smile on your face. It was quite embarrassing when four engines pulled up in the driveway!

Someone has to ask; I don't suppose you've got that on home cctv? We could do with another giggle

No.......... okay

I'll get my coat...........

 

Hi Bob,

If you want to eliminate the smoke completely, you could use G-Oil; it has a higher flash point than traditional 2 cycle oils and doesn't smoke or smell. It is also a renewable source of oil; it's made from beef fat rather than petroleum. I've used it in Stihl chainsaws and blowers and it is pretty amazing.

Mike