Engine flooding

🇮🇹💦 Of the Loin /

I got a new Dellorto Carb for my garelli because there was definitley a problem with the old one.

Now i started it up and it idled fine but choked because the tank was dry (at least I think, I didnt check the plug that time)

but im noticing that my plug is getting soaking wet. If i clean it up it will idle alright for about 30 seconds or so but then it begins to start stuttering and finally dies.

Is this something I can adjust in the carb or is it something else?

Re: Engine flooding

sounds like you need to figure out what's wrong!

Re: Engine flooding

haha

good job helping the poor kid out

Re: Engine flooding

carbs are all different .. start a thread with Dell orto in the title to attract dellorto experts.

it does sound like the new (?) carb has a problem. However, since you also had trouble with the old carb, it may be something else.

This spark plug fouling / flooding may be caused by repeated, failed attempts to start, so there's now a puddle of liquid fuel in the crankcase. Some of this liquid fuel gets sprayed up and fouls the plug.

This is nothing but a wild guess, but it points out an example of how your carb may be OK. A weak ignition or old spark plug could do it .. cause misfires and foul.. or even a too-small spark plug gap.

Re: Engine flooding

🇮🇹💦 Of the Loin /

I think the fouling was a result of the engine being flooded from unsuccessful tries.

It starts and works now, except it backfires when i accelrate above a certain point, and will stutter after i pull the throttle up about halfway and above during riding.

the plug has a nice tan/brown color on the inside so it seems to be firing good, do I just need to adjust the mixture screw on the side?

Re: Engine flooding

im no dellorto person .. but all these little moped carbs are simple and primative. So my guess is any mixture screws will have nothing to do with anything beyond setting idle mixture.

Re: Engine flooding

what you could try would be to take off the fuel line, unchoke the carb, and blow it out with compressed air, if you have access to it. im thinking its a stuck float

-ZeEE MoPed MOgUl-

Re: Engine flooding

🇮🇹💦 Of the Loin /

Ill try that, but its a brand new carb.

I was just talking with my dad and he said it was most likely a timing issue.

because its backfiring and stuttering above a certain throttle point and not at lower throttle locations.

could it be timing issue or an improper gap on the plug?

Re: Engine flooding

The spark misfires (no-spark for _any_ reason) and that power stroke's unburned fuel is pushed into the exhaust. On the next cycle the plug does fire.. Then hot exhaust gases ignite the raw fuel in the muffler .. and bang.. a backfire.

If it happens only at higher RPMs, check timing.

If timing is ok suspect a weak ignition.. like point return-springs can get weak and the points will float at high rpms, causing intermittant misfires.. or vibration rattles a loose wire connector.

But i wouldn't restrict the search to ignition alone. And rather than guess about it, i'd do a thorough tuneup.

Re: Engine flooding

🇮🇹💦 Of the Loin /

The backfire didnt so much come from the muffler as it did from the carb.

But that hasnt happened in a bit, Ive been running it alot this evening and it has seemed to smooth out the running alot

Re: Engine flooding

just keep running it.

Mopeds seem to take a while to run right after sitting for along time.

My motobecane ran like shitt, but now it runs awsome.

Re: Engine flooding

yur carb backfired????? you would be riding on a bomb!unable to relate what happened to you! i don't think carbs

backfire tho' i'm wrong most of the time.

Re: Engine flooding

Jason Luther /

has your ped ever ran right? are you sure you have the correct plug? i have never bought a ped (0-7 i think) that had the right plug in it. it wouldnt hurt to check and clean your timing though. if you set the point gap (see freds guide in the resources section of this site) to .016" that will get you close enough to proper timing for it to run okay

Re: Engine flooding

Patrick Mattison /

In my honda i had a spark plug. i ordered a replacement from powersportspro and they sent a cooler one. i changed some stuf and it didn't run right. now after i have parted it out, i'm thinking i may have just had too cool a plug. damn. if i just had a _wee_ bit more patience

Re: Engine flooding

🇮🇹💦 Of the Loin /

I bought the correct plug according to garelli specs.

It's gapped correctly and here is what seems to be my only problems at this point

occasionally at high revs there will be a backfire from the carb. It has knocked the air filter out a couple times (its a loose fitting one and doesnt really fit. I put the old dellorto one in there and it fits fine and doesnt come out)

I am also noticing a little lack of power both on hills and on straightaways. I figure that im not going to go very fast on hills anyways because I am 250 lbs, but I think that the problem is that its not getting the right fuel/air mixture at this point, and a sluggish or bogged down engine would indicate the fuel is too rich? the only possible thing I can do to fix that (the mixture screw is all the way in) would be a smaller jet?

Does anyone know what a new Dellorto carb comes stock with? the old one had a 50 jet and I havent opened up the new one to see what it has

Re: Engine flooding

hey maitlan, hows it goin? poor allen, what are we gonna do with him? we gotta start our own branch dude, later

Re: Engine flooding

spark plugs heat range does one thing.. At high speed, a plug's tip should stay hot enough to burn away all deposits that collected on it during low speed driving.

If your timing is close, and you still get a true backfire (backwards through the carb) you may have a mechanical problem ..

Have you guys removed the cylinder head and taken a look inside? Have you examined the exhaust port and muffler to see if it's clogged with carbon?

A chunk of carbon in the head can get really hot and remain red hot. This glowing hot thing can ignite fuel at any time, regardless of your "ignition timing".. maybe it will ignite when the piston is at the bottom and the transfer ports are open, as fresh fuel enters.

Im not sure if a clogged exhaust will do it. Logically, it seems that if hot exhaust cannot escape through the exhaust port fast enough, some of it will be pushed down through the open transfers, into the crankcase and back out the carburetor ..

Re: Engine flooding

🇮🇹💦 Of the Loin /

If this is a possible cause, would the fact that my exhaust gasket is broken at the moment and part of it could be inside of the exhaust pipe be a problem?

Re: Engine flooding

i dunno.. maybe..

There's a lot of complexity hidden behind a 2-stroke engine's mechanical simplicity, because everything happens at once... everything interacts. Exhaust is not to be taken lightly .. it's as critical as is the piston.

So, while searching for a cure and i come across something like that gasket or _anything_ else that's not correct, i just fix it.

Re: Engine flooding

🇮🇹💦 Of the Loin /

I am going to get a new gasket tomorrow. I think thats partially the problem here, but I'm fairly new to working on 2 stroke engines, and I barely know my way around 4 strokes

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