2-stroke engine start

[aerialcastor]

Hello,


I have been trying in vain for a few days to start a 2HP Evinrude 2.5-stroke engine.

Everything happened ...

After a lot of work I managed to spark. First victory.

As the engine did not start, I suspected a compression problem. Well seen one of the segments remained stuck to the piston. Takeoff of the piston ring. Second victory
Reassembly of the connecting rod, the annular bearing, the piston of the cullase y tout y tout ... To realize that I put the piston upside down and that it struck in the cylinder head
Reassembly of everything and reassembly in the right direction.

Engine still does not start ...
Checking the fuel, which was blocked, cleaning and reassembly ...

Attempt to start, we feel that it is not far he almost wants to leave but not leave ...
If I put direct gasoline in the combustion chamber the engine turns a few seconds then stops.

I hesitate between two problems:
- poor carb adjustment (screws tightened minus two turns)
-or segment not tight enough therefore depression not strong enough to suck the mixture in the room.

Opinions?

[Alain G]

Hi Aerialcastor


Change the carburetor diaphragms and if it doesn't work take compression because if the compression is too low the carburetor pump will not pump enough fuel.

You can do a test with oil in the cylinder that you put through the spark plug, it will increase the compression and you will see if this is the problem!

[Pascal HA PHAM]

hello Aerialcastor,

two potential leads
1 ° setting the ignition advance,
is it ok?
because there may very well be a spark but not at the optimum angular point relative to TDC.

2 ° when you remove the candle and with a syringe you "pchitt" a small squirt of mixture in the cylinder (piston halfway up stroke) and you put everything back in place: does it cough or not ....? if it fires a little it is because there is rather a problem of gasoline supply .... if it does not cough at all hum ..... put a new and hotter candle and start again!

but it will do it I feel it!



A+



pascal

[aerialcastor]

Uh what are the diaphragms ?

There is no petrol pump, it falls by gravity into the fuel.


I have good news
I managed to run the engine at full throttle for almost 1 minute

then he stopped


Suddenly I tell myself that it is not the compression but the fuel.
There must be a bastard still worth restarting everything ....

Otherwise for the bad news the launcher has (still) dropped and I begin to have blisters in my hands.


If not, how about taking the cuts?

[Pascal HA PHAM]

you need a small dial compressiometer that you put in place of the spark plug .... the best is to take your "évinrude" to a motorcyclist / mechanic not far from your home and it measures you the compression in 2 shots large....

but as you describe it it is the fuel supply that would fish ...
A+
Pascal HA PHAM

[Alain G]

Hello Pascal!


It is preferable not to put the gasoline directly in the cylinder on a 2-stroke because it washes the oil layer and it could seize up, I recommend adding gasoline by the carburetor and the adding oil to the cylinder for a test!

The lack of compression has 2 effects on this kind of engine:
-Lack of compression of the mixture which creates a difficulty to light it.
-Lack of compression which makes the diaphragm pump inoperative because it is activated by compression in the base of the motor.

Be careful if the compression is too low and the engine starts, it can seize up, so if the engine does not keep the idle speed do not run it unnecessarily without checking the compression using of a gauge.

[Alain G]

Uh what are the diaphragms ?

There is no petrol pump, it falls by gravity into the fuel.


I have good news
I managed to run the engine at full throttle for almost 1 minute

then he stopped


Suddenly I tell myself that it is not the compression but the fuel.
There must be a bastard still worth restarting everything ....

Otherwise for the bad news the launcher has (still) dropped and I begin to have blisters in my hands.


If not, how about taking the cuts?

The diaphragms are in the fuel pump which is integrated on the carburetor!

If there is none, you have a fleet located in the base of the carburetor!

[aerialcastor]

As ignition I have this:



If I say no bullshit we can not pay the advance?

I do have a floating ring which is connected to a punch which aims to always have the same level of fuel in the fuel

When I put gasoline in the room it is added to 2% oil.

[Pascal HA PHAM]

you can make a close-up of the breaker and its plate: normally an advance is set!

If you use 2 stroke mixture and you inject it sparingly into the cylinder and you do not snore the thing to donf, there is no big risk of damaging anything! it is just to diagnose / locate where the problem is that this test should be done.

A+

[aerialcastor]

For close-ups here:





Sorry for the framing but my device doesn't have a practical screen.

There is indeed a small adjusting screw.
For me (and maybe wrong) this screw to make sure that the "coal" constantly touches the tree in the center.
Besides, at the beginning the coal did not touch all the time, I had concluded that that was why there was no spark.