Difficult to start/cuts out/bogs down/backfires. Help!

[L14MNP]

My car cut out after a roll (iirc). Seeing as a rear upright had came away from a rear tower support at the same time, I wasn't too concerened, as it was time to go home anyway.

I actually thought the fuel level had dropped below the pick up just at the right moment. I guess not now though!

Here's where I'm at, I repaired the tower insert and refilled the fuel tank just before, then when attempting to start the engine, it didn't want to know. I got it spluttering and then it eventually fired. I assumed the fuel wasn't getting to the carb, even though the feed line and bulb are full.

Once running, it cut out. This process repeated for a few attempts. I tried fethering the throttle but if didn't seem to make much difference. Some tries would allow WOT, but it then bogged down as soon as I came off the gas, and subsequently died. It backfired a couple of times too (when dying) and also seemed to be running at a higher/erratic idle.

I thought it would sort itself out if I let it idle, or drove it, but nope.

It now doesn't want to fire again, won't even splutter. I reckon i could get it away again, but something is obviously wrong, hence asking the experts at LSF! Plus I'm afraid I will break the pull start!


Any ideas? From my very limited knowledge, it almost seems like the carb settings are wrong. This can't be possible though, as I have not touched them since it ran fine.


Any help appreciated! I was going to go out with this tomorrow morning. Been looking forward to it whilst at work. :lol:

 

[Lan-Ed-Tul]

rest carb needles to factory settings, theyre mentioned in another thread how many turns out from full seat for each needle. also pull plug see if its soaked with gas, dry off, one suggestion made is to turn upside down and pull the starter a few times to blow excess fuel from cylinder, sit back upright reinstall plug, and try to start.

one other thing is to yank the engine cover and check the coil gap. use a business card between the coil and flywheel for gap setting, retighten the bolts holdin coil the card should give you correct gap. do remember to take card out, lol put cover back on and try to start. also you can slap plug in plug cap hold the spark end on metal of engine roll over engine to check for a spark

 

[L14MNP]

Cheers Lan. Will check those shortly mate. Got painted parts drying in the garage, so it's a no go zone atm!

I never checked for a spark yet as I assumed it was sparking fine. Will do though. I read a bit in the other lads thread about the carb settings. Will use that for reference.

Thanks for the speedy reply!

 

[Lan-Ed-Tul]

np, if that air filter is soaked too might pull that apart and let air dry out while you are doin the other checks. one other thing to check, if youhad the fuel lines taken off, make sure you put them back on right. the upper connection is fuel return the lower connection is supply

 

[L14MNP]

Air filter is dry mate.

Found at least part of the problem!


This fiddlesticking 'cage' is made of cheese!






As you can see, the roll over has pushed the plastic cover above the engine into the plug cap and cracked, bent and closed the gap on the plug! It has also marked the underside of the cover.



TORCH plug replaced with an NGK, car is not flooded, but still refuses to start. This has to be ignition related, given the previous symptoms.

The spark is much brighter and stronger with the NGK now. I still haven't checked the coil gap, as tbh I expected it to fire after replacing the plug. It kinda spluttered once, but that aside, it doesn't want to go.

What is the correct starting sequence? I ususally just pull the start with the choke open, until it splutters, close the choke then pull again and it fires.

Is this what I should be doing? I guess I need to check the coil gap too, seeing as this is an ignition related issue.

Damn thing!

 

[Lan-Ed-Tul]

choke closed, a pull or 2 till it tries to start open choke and usually fires next pull

 

[handgrenade73]

?

Check to see if you cracked the head anywhere from the roll over. Theres no reason the roll over would cause the plug gap to move unless the head moved and the piston hit the bottom of the plug..Sounds like you have a leak somewhere

 

[mickey]

i started with the same buggy as you have . the motor only lasted a tank and a half before it puked out. the plating on the cylinders is not very good in the 23cc. i would pull the cylinder and have a look. and oil the air filter it shouldnt be dry.

 

[L14MNP]

Check to see if you cracked the head anywhere from the roll over. Theres no reason the roll over would cause the plug gap to move unless the head moved and the piston hit the bottom of the plug..Sounds like you have a leak somewhere

Yeah, I realised after I typed that. What an idiot lol.

Will check the head over tomorrow. The threads for the plug are still fine, so I hope the head hasn't moved. Maybe the plug was just gapped badly? Although I would imagine it wouldn't run with such a small (no?) gap?

Mickey, that doesn't sound too clever mate! I really don't want to spend a fortune on this hobby. I know certain things are needed, but I want it to cost me as little as possible. I'm trying to restore/mod a real car atm lol.

Will oil the filter. I meant it wasn't soaked with fuel.

Thanks everyone.

 

[Lan-Ed-Tul]

it is odd the gap is closed, or least it looks like the bar is touching the electrode. youll know if it hit the head if you see a coresponding ding/dent/scratch where the plug is in middle of piston top.

to ease your mind a lil bit, mine is a 29cc and run bout 3 gals at very least and engine still goin strong. its just a luck of draw it seems at times with the engines, some folk it goes to crap real quick and others, like mine have no issues.

ive rolled mine too and medium throttle and didnt do any damage cept body.
yours buckling like that, either the parts were inferior quality, or it took alot harder smack than you thot it did.

 

[L14MNP]

This is sorted now everyone. I took it to a model shop this morning, and the guy refitted the spring in the plug lead. I thought it was refitted correctly after I pulled the lead off and the spring was stuck on the plug - as it was sparking during bench testing, but obviously not lol.

As a bonus, the guy tuned the carb. He said it was only opening 3/4 at WOT, and also fiddled with something to make it pull away quicker. Cool.

Thanks for all the help. Please see my other post for further issues.
(btw, the plug did still have a minisucle gap.)