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Author Topic: help - how do i know when engine is four stroking when setting carb  (Read 2950 times)

digger

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help - how do i know when engine is four stroking when setting carb
« on: March 10, 2009, 06:20:47 pm »
hi people could you please help me i don't want to sound thick but could some one help me with the term four stroking when setting a carb on a zenoah , i have looked at different web sites but still not to clear what I'm looking for . if you would like to call me thats not a problem  MODERATEDhelp is greatly needed
thank you
regards
    Darren

Personal phone number removed forum


Brian
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malcolmfrary

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #1 on: March 10, 2009, 07:09:44 pm »
As I recall from scooter days, if it goes "VROOM" it is working as a two stroke, and things are as they should be.  If it goes "put-a-put-a-put" it is four stroking, and things are not as they should be.  It is turning over with enough momentum to get past a dead stroke and get enough mixture to be set off on the next firing stroke.
I will now back out and let someone who actually knows about small infernal combustion correct me.
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DickyD

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #2 on: March 10, 2009, 07:17:17 pm »
Putting your phone number on here is not a good idea Darren  >>:-(
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digger

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #3 on: March 10, 2009, 07:23:42 pm »
Quote from: digger on March 10, 2009, 06:20:47 pm
hi people could you please help me i don't want to sound thick but could some one help me with the term four stroking when setting a carb on a zenoah , i have looked at different web sites but still not to clear what I'm looking for .
thank you
regards
    Darren
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omra85

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #4 on: March 10, 2009, 08:11:46 pm »
Darren
This should answer your question (although it is referring to glow plug engines the same applies to petrol)

A model engine makes sounds that will tell you how it's performing. You'll have to listen very carefully for them, recognize their message, and make adjustments to the fuel control needle valves accordingly. The mixture of fuel and air is controlled by the amount of fuel metered by the needle valve.

SLOPPY RICH MIXTURE running is characterized by a very slow, irregular, sputtering exhaust sound. The exhaust gas will be very smoky and contain many droplets of oil. NEVER RUN AN ABC ENGINE AT THIS SETTING. The cylinder is not able to heat properly and the fit will be ruined in a short time.

RICH MIXTURE running is characterized by a slower, sometimes irregular, sputtering exhaust sound. The exhaust gas will be smoky and probably contain small droplets of oil. NEVER RUN AN ABC ENGINE AT THIS SETTING. The cylinder is not able to heat properly and the fit will be ruined in a short time.

FOUR CYCLING or SLIGHTLY RICH running is a rich type setting, but it is fast enough to push the boat. This is the setting you normally look for before launching the boat then further adjustments can be made to fine tune the engine.

PEAKED OR TWO CYCLE. As the main needle is closed (clockwise), it reduces the amount of fuel mixed with the air drawn into the engine. At a specific point, which varies with each engine, air temperature, altitude and relative humidity, the exhaust note will change quickly into a smooth, powerful note. If the needle is closed further, the note will stay smooth, but will weaken. The peak occurs just at the break point from a rich setting and further leaning will ruin the engine. A lean setting raises the engine heat above the safe point, reduces lubrication, and destroys glow plugs due to high combustion temperature. This is very harmful to the engine and your investment. Learn to tune the engine before flying. Remember, a little rich is always preferred for long motor life.

(from the K & B technical help site)

Danny
PS So Malcolm the Mod was right  :-))
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dreadnought72

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #5 on: March 10, 2009, 08:24:13 pm »
I had an aero Enya-15 back in the past, and it was obvious when it was four-stroking (putt-a-putt) compared to two-stroking (rrrrrrrrrroowww). You WILL know the difference. Get it going "wet" and four-strokey, then lean up the fuel. It'll take off.

Andy
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omra85

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #6 on: March 10, 2009, 08:25:30 pm »
This link will take you a HUGE page of links to EVERYTHING you always wanted to know about models  :-)) :-))
http://homepages.ihug.co.nz/~atong/

Danny
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tigertiger

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #7 on: March 11, 2009, 02:10:45 am »
Hi Digger.
and anybody else who this may apply to.

If you do need to chat with people on the phone then ask people to send you a PM, or if you see that someone on here has the knowledge then you can PM them.
You can put you phone number in a PM. This is safer than doing it on open forum, where anybody, including non members can see it.

Good luck with your problem
Mark
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digger

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #8 on: March 11, 2009, 07:48:15 pm »
sorry about that mark , will not happen again
regards
Darren
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omra85

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Re: help - how do i know when engine is four stroking when setting carb
« Reply #9 on: March 11, 2009, 08:18:06 pm »
Darren
Another good way of telling if your engine is four-strokiing is
-
-
-
-
when you keep getting overtaken  -  by the same boat  ;) %) {-)

Danny
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