engine troubles

yakken

Well-Known Member
i went to fly my 50cc bird today and the damn thing wont start. i took it home and started checking things out and found one of my a123 batts took a crap. so i hooked another battery up to my ignition and it still wont start. if i pull the plug and put it in the cap it has a good spark. engine is getting fuel. could my ignition have shorted out and ruined my battery? is it shorting to the engine when i put the plug and cap back on the engine? any help from you guys would be greatly appreciated.
 

Jedijody

Proud father of Soldiers
I wouldn't say it couldn't happen but I've never seen an ignition ruin a battery, I have though seen a battery take out an ignition.

CAUTION HIGH VOLTAGE, DO NOT PUT TOUNGE IN SPARK PLUG CAP!

Pull the cap off the plug and remove the plug from the engine. Put a small screw driver down into the plug cap all the way to the bottom, hold it so the screw driver shaft is centered in the plug cap opening. Turn the ignition on, rotate the propeller and observe the spark. It should be arcing from the screw driver to the metal plug cap shell, if it is, remove the screw driver and turn over the engine a few times while looking down into the bottom of the plug cap. There should not be any visible arcing, if you see arcing there is a hole in the silicone boot and you'll need to replace your spark plug cap. This happens when someone is ham fisted with the plug cap or from a hard impact to the plug cap while installed on the spark plug.

If the plug boot has a hole in it there will appear to be plenty of spark at the spark plug. But, compression pressure and wet fuel on the plug while trying to start raises the resistance at the plug higher than the resistance to arc to the metal plug cap shell.
 

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yakken

Well-Known Member
I wouldn't say it couldn't happen but I've never seen an ignition ruin a battery, I have though seen a battery take out an ignition.

CAUTION HIGH VOLTAGE, DO NOT PUT TOUNGE IN SPARK PLUG CAP!

Pull the cap off the plug and remove the plug from the engine. Put a small screw driver down into the plug cap all the way to the bottom, hold it so the screw driver shaft is centered in the plug cap opening. Turn the ignition on, rotate the propeller and observe the spark. It should be arcing from the screw driver to the metal plug cap shell, if it is, remove the screw driver and turn over the engine a few times while looking down into the bottom of the plug cap. There should not be any visible arcing, if you see arcing there is a hole in the silicone boot and you'll need to replace your spark plug cap. This happens when someone is ham fisted with the plug cap or from a hard impact to the plug cap while installed on the spark plug.

If the plug boot has a hole in it there will appear to be plenty of spark at the spark plug. But, compression pressure and wet fuel on the plug while trying to start raises the resistance at the plug higher than the resistance to arc to the metal plug cap shell.
i am going to go try it now. thanks
 

yakken

Well-Known Member
i did the screw driver test and it arced against the cap. turned it over with nothing in it and it was arcing like crazy. thanks for the help. i rdered a couple cap kits from V.V.

now i have another question. i have a brand new fromeco a123 battery in the plane. when i got it home there was blue lights on under the shrink wrap that i have never seen before on the battery. so i checked it and one cell was real low. i put it on my balance charger and it was losing charge on both cells trying to charge it. BTW i always balance charge them. i am going to call fromeco about it but will this battery catch on fire?? its not hot but i would be afraid to ship it back if it would. i have a few of these batteries and they have been flawless. it kinda freaked me out when i seen it glowing at first.:yikes:
 

yakken

Well-Known Member
called fromeco today on my battery that took a crap. guy i talked to on the phone was very nice. they are taking care of me on that battery. :thumbsup:
 

Vital-Rc

Well-Known Member
I've seen someone charge an a123 on nimh setting for over 45 mins and it got hot and made some weird popping sounds. Let the battery cool back down and inspected for damaged areas. It was balanced charged and brought back to life (no pun intended). Gotta love a123 cells, they are rock solid. :)
 

BRUTUS

Plank Junky
Lifetime Supporter
Bombproof baby.

Yakken- how old were your other 123's? I just got some and assumed they had the same 2-3 year life span as most other batteries...
 

yakken

Well-Known Member
My other a123's are three years old and have had no issues. Between me and my brother we have a dozen fromeco a123 packs. Probably over a thousand flights on them. This one pack was a new one that went bad. Fromeco is replacing it. I love a123's I won't use any other battery.
 

Myron

Myron
Good morning
I have a dle 30 with side carb tillotson.
After the 1 1/2 gallon brake in, I put it on my brand new Yak 55.
I noticed problem on the low idle I cannot go lower than 2000 rpm the high rpm is 6950 with 19x8 jfx.
The problem is that the engine cannot hold lower that 1800 without stop and even in 2000 sometimes had the same problem.
Some guys in the field propose to change to rear carb.
Any suggestions?
 

yakken

Well-Known Member
just don't stick you finger in the prop :wink:
Last weekend I was at the club and there was a guy with a glowtard profile. He kneeled down in front of his plane and flipped the prop with his finger with no restraint. I just happened to see what was going to happen and grabbed the rudder just as it started at WOT. :yikes: he almost got chewed up.
 

Dadstoysbg

Well-Known Member
That's one of the reasons I like my new 11x. You can set the safety so the radio won't come on if the throttle is advanced or you have the rate switch turned up. It also beeps at you too. almost like having your wife with you in the start up area. Dennis
 

yakken

Well-Known Member
Need some opinions please. Me and buttface spent about six hours yesterday trying to tune my brothers engine. We figured out that w/o the coal on it runs like a top. Put the cowl on and it just won't tune and the engine runs like sh!t. We ran a tube off the carb into the fuse but it didn't help. This engine is baffled well. My theory is that the air is creating a vacumn in front of the cowl and starving the carb for air. Do you guys think if we put a hole towards the front bottom of the cowl that it will let fresh air to the carb and cure the problem.
 

Jedijody

Proud father of Soldiers
Some pictures would be a lot of help but from your description, it sounds like the carb isn't getting good air flow into it. Either duct clean outside air to it or cut a hole for it.
 
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