x-craft

My Feedback: (3)

I have a G-38 that I picked up used here on RCU. If I could remember who I got it from I'd drop them a line but it's been a while now. Anyway, I can't get the darn thing to even pop for me. I have a spring started installed, there is fuel and fire but can't get anything to happen. I flipped it for what seemed like forever. My procedure is with the switch off I throttle up and cover the stack until I have fuel in the carb. Throttle down and switch on then try to start and absolutely nothing happens. I have a G-62 that starts on the first or second attempt, I used to have a G-38 previous to this one and had no problem with that one either. Anybody have any thoughts? I have checked the coil gap and replaced the plug.

bhole74

The first time I fired up my G-38 took about 30 minutes. It sounds like you may be flooding it. Make sure your plug is dry. Full choke, full throttle with ignition ON until it pops, then open choke and lower throttle to fast idle, it should fire. If it doesn't, try opening the idle needle a little bit. My BME 50 wouldn't start for the first time because of lack of fuel at idle. Make sure you have a helper hold the plane or tie it to something, you don't want that prop coming at you.

x-craft

My Feedback: (3)

This motor does not have a choke on the carb so I can't use your procedure. Tonight we primed it and cranked on it with an electric starter. There isn't even so much a single pop. We tried Ether with no results in any way. I am totally stumped. A friend of me is a motor man and he's going to look at it. If we figure it out I'll post. So far, there has been three people involved with this motor and it's still a no start. We've all owned big gassers, we all own G-38's and this motor is turning into a total curse. That's what I get for buying a used unknown motor.

mrbigg

My Feedback: (21)

I had the low end too lean and it wouldn't fire at all. runs great now.

mrbigg

My Feedback: (21)

I had the low end too lean and it wouldn't fire at all. runs great now. Is the ignition switch hooked up right? Are you sure your turning it on and not off before flipping? It's not like I would have done something as stupid as that................[sm=lol.gif](that's exactly what I did!)

x-craft

My Feedback: (3)

ignition is correct. I double and triple checked this.

beepee

x-craft,

I will ask it a different way: make sure the switch is "OFF" when starting the engine. "ON" to kill it. To check the working of the switch, you can disconnect it and start, but then you have to have another means of killing the engine. Fire, fuel, compression - these gassers can't help but run.

Good luck,

Bedford

x-craft

My Feedback: (3)

The switch has been checked and checked again. Off is on, on is off. Spark has been verified several times thus confirming the switches position. You are right, these motors can't help but run. That's what's so puzzling. Even Ether didn't make it pop[] I even verified the spark in the compression cycle thinking it was possible the flywheel had slipped somehow. That is good too.[:@]

thevirginian

x-craft,
remove the magneto wheel and check if there is a key in the slot of the crank.

Richardrc

Did you check to make sure you have the correct spark plug? Maybe it isn't creating unough/proper spark.

efrakjr

My Feedback: (9)

1. Plug wire could be shorting to ground when on the engines spark plug (wire positioning problem)
2. Make sure that it is a counter clockwise running engine (should rotate toward the flywheels fin cups)
3. Close the gap on the spark plug to around .010 to .015 inch (spark may not be hot enough to fire under a compression condition)
4. Coil air gap should be about .020 inch
5. Magnets may have lost there strength (not likely)

Good luck, let me know how it goes.
efrakjr (Earl)
[email protected]

NM2K

My Feedback: (14)

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Look at the bright side. It's only a collection of parts. It is not alive. It has no will of its own. If all of the requirements are met, it cannot help but run.

One thing worries me. No popping at all when the ether was injected into the carburetor? That is not good. It sounds as though none of the ether made it into the cylinder. Is the throttle plate installed upside down?

The engine does have some compression, right? Compression plus ether means you should be getting a pop at least. No, I don't recommend using ether for this application - but I can understand why you did. Sometimes a man gets desperate. <G>

These engines won't start unless the spark plug IS wet from choking. Too much prime? It happens. Pull the plug drain the cylinder and now you have the perfect amount of prime in the engine.

Could it be that the carb plate is closed too far, or installed backwards? That would put the kai-bosh on running, even with ether. Good luck.

Cyberwolf

My Feedback: (4)

Theres only 4 things that will make the engine run Air ,fuel,spark and compression of course these have to be in the right working order for it to run or in your case start .If the carb is ok and the plate hasn't been reversed next I would check the plug wire ,you said that you checked the spark and had some ,but I take it that was off the spark plug itself ,the boot can be shorted out to the wire and cause a missfire and the plug won't get any spark or not enough when on the spark plug itself .Its been a while since I messed with a G-38 and I can't remember if it has the 2 coils or not ,if so check each one of them for proper output.
If all else fails do a compression test on it , a 2 stroke won't run if they have to low of compression.
Hope this helps some .

TomCrump

It may be compression. Tim and I tried three coils, all had similar spark. We know that fuel is getting to the plug.

This is the first gasser that I haven't been able to make run.

Cyberwolf

My Feedback: (4)

The crank key has been mentioned and I take it you have checked it .And checked the spark with the plug in the boot grounded to the engine ,it has fuel to the plug .I guess do a compression check dry and wet and let us know what you come up with .

Nickrc3

My Feedback: (6)

You mentioned on vertifying spark? How did you install the ignition kill switch via the magneto?
If you simply cut that short black wire and tied the switch in series with it, she'll never start. I just did this on mine, till I learned the proper modification of soldering across that magneto lead.

NICK

TomCrump

I'll see if I can borrow a compression guage and give it a try.

I bet Tim is checking his kill switch wiring right now. Thanks for the tip.

x-craft

My Feedback: (3)

I soldered a wire to the tab that the little black wire is also attached to. I then attached a wire to ground and tied the two together with a switch. All seemed to be good. I might add that the other two coils I tried had no kill switches installed so I can rule out that issue anyway. With the spark plug out we had fuel running out of the cylinder so I know fuel is getting in there. An attempt was made by spraying ether directly into the combustion chamber via the exhaust outlet. No fire in anyway there either. Don grabbed a bottle of oil and shot it down into the cylinder then put the plug back in. The compression immediately felt better until the oil worked down into the crank case. The feeling is that it's compression but I still can't believe that it won't do anything at all. This is one frustrating motor that just doesn't want to live. All these are great suggestions and I think all the bases have been covered. Where to go now is probably sending it in and having somebody else fix it. I could easily order a cylinder, piston and ring, replace them and hope that it fixes the problem but I'm not exactly sure it needs all that.

WILDCRASHWILLY

Is it possible that the spark plug itself could be defective? Just something to consider if you have access to another plug. I have heard of plugs having internal cracks in the porcelin and thatunder compression, the spark going straight to ground at the threads instead of jumping through the electrode the way they are designed to do.

Just a thought as you have covered several very viable scenarios and all the other suggestions mentioned above are possible.

I had this happen on a chainsaw once. Plug would fire when laid next to the cylinder head wher I could see it but would not fire in the engine. After scratching bald spots on my head I replaced the plug anyway and the thing ran perfect.

Just another idea.

x-craft

My Feedback: (3)

Good idea Bill, unfortunately I've tried two other plugs already. A brand new one and an old one that came out of another G-38.

Cyberwolf

My Feedback: (4)

I really wouldn't think it would need a piston and new jug if the compression is low,you may get by with just a ring and a hone job.Unless it has scored the wall or piston or both .Anyway I am really curious to see what the compression is ,thats a given and easy to rule out if its good or bad.
Ok you have laid the plug on the engine and turned it over to check spark correct .
Gas running out the plug hole is not a real good sign either .
But even if its flooding it I would think at sometime the mixture would be close enough to pop ,unless its a steady downpour inside the cylinder,then it won't do squat .
This is really tough to make a proper diaganosis without having it to test and so forth .But never fear one of us will hit it on the nose.

x-craft

My Feedback: (3)

when we had fuel running out of the cylinder it was on purpose. The plug was removed and the carb plugged off to choke it. Tom and I cranked it over until we saw fuel coming out of the cylinder just to see if it was getting into the chamber. Yes the plug was grounded out and we got good spark with all three coils. The inside of the cylinder looks good and from what I can tell the piston looks ok too. I was going to order a ring when I ordered the new replacement motor but for some reason I didn't. I guess I didn't want to throw parts at it if I wasn't sure. I'm going to have to look and see if I still have my compression checker. What should I see in it?

Here's what I do know, if I pull the plug and put my thumb over the hole and flip the motor over I can feel the pressure but my thumb stays in place. If I do the same with a brand new G-38 the pressure blows out. There is a very noticable difference.

x-craft

My Feedback: (3)

Good news.............................no, the motor still has not started. I did find the person I bought it from though. I've e-mailed and PM'd but am waiting for a response yet. I'm not asking for the world but I'm hoping for a fair equitable gentlemens solution. I'm sure it's repairable and if something can be worked out I'll be happy.

Cyberwolf

My Feedback: (4)

After checking a few things your compression should be a min of 80 PSI for it to run and thats the low side .Im glad you found out who sold it to you maybe they can shed some light on the subject .Good luck.

x-craft

My Feedback: (3)

I found a compression gauge and I got the compression to hit about 70psi. It was hard to hold the motor and do this since I don't have it mounted anymore. To be more accurate in that manner I'll have to screw the motor to something and try again. Thanks for that info, it's good to know. I was figuring the compression should be at least 90 going by what one of the guys who looked at it told me.