Sessholvlaru

I'm stumped here. My G260PUM (the 26cc boat motor) will not start. It has spark (strong enough to see outside in the sun) and the plug is wet with fuel. I even dripped some gas into the combustion chamber, nothing. I find it hard to believe that with air, gas and fuel it will not even pop. I'm using a 32:1 mix, just like is called for.

Any tips? Could the timing be off? I do not know the history of this motor, other than that I was told it was running not long ago (likely bullsh*t at this point). Thanks!

av8tor1977

My Feedback: (6)

Probably flooded. Disconnect the fuel line, leave the spark plug out, and spin it over to clear the flood. Then clean and dry the plug and re-install it, hook up the fuel line, and try to start it with no choke. If after a while it still won't start, check the plug again. If it is wet, you probably have a carburetor problem.

AV8TOR

w8ye

My Feedback: (16)

I experienced this with a Homelite 25 weed whacker a couple weeks ago and the bottom line is that the muffler was plugged by a blue wasp nest (mud Dauber).

Knocked the nest loose with a screw driver and the engine ran fine.

A guy gave it to me because he couldn't get it to run several years ago and I just got around to looking at it.

Sessholvlaru

Hi guys.

It is not flooded. Also, there are no obstructions anywhere. I had the carb apart and no signs of anything wrong. Spark is strong and blue. Fuel is getting into the combustion chamber. This is really boggling me. Spark+fuel=combustion...or so I thought.

Could the timing be that far off as to not even pop?

w8ye

My Feedback: (16)

It takes . . .

The right air/fuel mixture

Spark at the right time

And compression

To make one fire.

You are missing one of these?

Antique

My Feedback: (4)

Take the mag rotor off and check for a sheared key.....

Sessholvlaru

How does the mag rotor come off? I'm looking at it right now...

Antique

My Feedback: (4)

The rotor is on a taper, unscrew the starter nut and pull it with a small 2 jaw puller..
Put some rope in the spark plug hole to keep thepiston from moving...The factory piston stopper is a 10mm aluminum piece that screws into the spark plug hole.... A 10mm bolt will do the same thing....

Sessholvlaru

Don't have a puller. Darn.

Antique

My Feedback: (4)

Piece of 3/8 steel about an inch wide...Drill a hole in the middle for a 3/8=24 bolt, 2 holes to put 8mm bolts in the
8mm threaded holes in the rotor...
Been using mine for 24 years...

Sessholvlaru

Got the rotor off. The key is not sheared. What else could this possibly be?

spaceworm

Have you tried a NEW plug? Worth a try if you haven't.

Sessholvlaru

Yes, brand new plug made no difference.

w8ye

My Feedback: (16)

You need to send that engine to Antique and let him get it going?

Sessholvlaru

I'm trying to get it going on my own, even though I am about to step on this boat. There are only so many reasons why it won't run...but this is a real mystery to me.

1) Bright blue spark
2) Getting fuel (even dripped fuel into combustion chamber, not even a pop)
3) New plug
4) Key not sheared
5) Good compression
6) Good fuel

I took the motor apart and there is some scoring on the sides of the piston, mainly on the skirt. Maybe this motor was run without oil in the fuel at some point, I have no way of knowing. Otherwise the motor looks nearly new. There is no play in the bottom end and the piston ring is free. The EI is not adjustable, so that isn't the problem. The carb was completely disassembled and nothing seemed out of place.

captinjohn

Try a small shot of engine starting fluid in carb throat. See what that does. Also I do not know how you are starting it....but it may need to be spun a little faster to start...the way its tuned. Capt,n

Sessholvlaru

I don't see what a shot of starting fluid would do that gas in the combustion chamber wouldn't... Something is wrong here.

The motor is a pull-start and there really isn't a way to get an electric starter on it.

Sessholvlaru

This is driving me mad. Anything look out of place here?

Sessholvlaru

Made another attempt, still nothing. With the plug out, I can see the mist of fuel come out of the C.C. with a flashlight. Is there some condition where the plug will spark when held against the head but not when installed?

Sessholvlaru

Tried again, this time putting some nitro in the chamber. Nothing. Not even a hint of combustion. If anyone is in the Caldwell area, you may very well see an 1/8 scale Miss Bud on the curb tonight.

mandx

i'm also using zenoah g26 for my airplane....once i had a problem starting it..I checked the curb., fuel line, timing, etc.....I found out that the E.I. wire had a small cut in which it did not work or gives out current to fire the spark plug.... I fixed the problem by soldering the wire and until now i have not encountered the same problem again.... Try to check you E.I. if it gives current to your spark plug.

av8tor1977

My Feedback: (6)

Check the compression. It should be at least 60 psi to run. (Hopefully it is much higher.)

I still say it is flooded. Try what I said in my first post. Take out the plug, unhook the gas line, and spin the engine over. Clean/dry the plug, replace it, and try starting it without the fuel line hooked up. I have had severely flooded two strokes take a BUNCH of pulls on the rope with the throttle open and the fuel off to clear out a flood, even after spinning them over with the plug out to clear the flood. I have had malfunctioning carbs completely flood the engine in two pulls of the rope....

AV8TOR

rglgatortail

My Feedback: (7)

In your first picture you were showing the back of the motor but lets look at the carb, in the picture as you look at the carb there is a screw that has a combination of philips and straight slot head that screw controls the idle, you turn that screw clockwise will raise the idle (and of course you turn it counter clock wise will lower the idle), your symptoms kinda tells me that you just dont have a set proper idle so turn that screw maybe a half a turn clock wise and try to start the motor but do this with the fuel line removed so you dont have a run away engine from a too high of a idle, i suggest to remove the fuel line and put several drips of fuel thru the spark plug hole and try till you get a pop and a run that way when it does run it will just take off from the drips of fuel. I think that if the idle is set too low it just aint getting enough air for it to burn the fuel that its getting, so if the idle is set too low its kinda acting like a choke and then you are just flooding the engine.

dingo9882

I had a similar problem with a fox 4.2 recently. I have just one question though. Is fuel coming out of the carb at all? The reason why I ask that is because I had junk in the carb needles. I actually had to pull the needles out and blow them out with air. I also had to blow air through the port that meters the fuel going into the carb. It sounds crazy but try it. Also, try starting the engine at full throttle. May sound like a bad idea but I had to do the same thing to my 4.2, that how I found out there was stuff in the carb. It would run at full throttle but then die at anything below that. One more thing, check that the diaphram and everything is installed correctly. If it is backwards or the carb is put on backwards that would cause this same problem. Just check to make sure. I have made silly mistakes like that and had the same problems.

Sessholvlaru

Trust me, it is not flooded. I know because I have taken the motor out/head off more than once. I now believe it is a gasket problem. There must be leaks somewhere.