Garelli revs super high when starting then dies soon after. Air leak?

I've got a 1978 Rally Sport no mods, all stock. The thing hasn't gone more than around the block in years. I could get it to start last week but had little power and wouldn't idle.

Swapped in a new rubber clutch and cleaned the carb last week. Put it all back together today and kicked it until it started. This is where I am getting confused.

Once it starts it revs like I have the throttle is wide open, but i don't. Then after about 4 very intense seconds it dies. 5 more kicks it starts up and sings like a bat out of hell then dies.

I tried doing spray test but its hard to tell since it will only continuously run for 4-10 seconds. When I did spray it, i didn't notice any "instant kills". What would cause it to rev SUPER high then die?

Re: Garelli revs super high when starting then dies soon after. Air leak?

if your throttle slide is fully closed then it will not rev up unless....there is an air leak. Suspect ignition side crank seal.

Re: Garelli revs super high when starting then dies soon after. Air leak?

August Adams-Miller /

Probably an air leak but could potentially be that your idle screw is just cranked up way too high.

Re: Garelli revs super high when starting then dies soon after. Air leak?

I also think the idle screw or something is keeping the throttle open a little. To rev SUPER high for 4-5 seconds needs air and fuel.

Maybe an air leak and float not set correctly?

Just taking some guesses based on the items that were serviced and that it wasn’t doing it before.

Does it respond to throttle movement while it is revving on the stand?

Re: Garelli revs super high when starting then dies soon after. Air leak?

Richard Eberline /

fuel strainer inside the tank is dirty, cap not venting and a for sure air leak.

Re: Garelli revs super high when starting then dies soon after. Air leak?

Honkycat - You're on to something - it needs to be getting fuel and air and nothing is changing when I mess with the throttle. my cable and throttle feel pretty rusty and crunchy. I think something is caught open. I ordered a new cable yesterday assuming my slide is stuck open due to a shit cable.

However - lets assume it is stuck open and that is why its reving super high.. why is dying at full throttle?

Re: Garelli revs super high when starting then dies soon after. Air leak?

If everything is perfect, besides a stuck throttle, I think it would happily run away on the stand until it overheats and seizes. Which should take more than a few seconds.

I would take off the air filter and back the idle adjust screw out while watching to make sure the slide comes all the way down. Maybe before that, I’d make a new gasket for the intake manifold.

It would die at full throttle with an air leak because the mix is way too lean. Closing the throttle with an air leak allows enough air in to burn off whatever fuel may have spilled in from the carb being primed or something. That’s why I suspected the float not being adjusted right. After that initial fuel excess burns away the mix is too lean again and the engine dies.

A stuck throttle has a pretty distinct feel though. So, I think you’d know if that was the culprit immediately.

I’m gonna stop there because I’m drunk and constantly deleting and fixing my typos is hard. And I’m not sure if I’m making sense.

-respectfully

Re: Garelli revs super high when starting then dies soon after. Air leak?

Ha!! My friend told me last night that you cant come close to solving the problem on your ped until your at least 6 beers deep.

Re: Garelli revs super high when starting then dies soon after. Air leak?

> Aaron Turek Wrote:

> -------------------------------------------------------

> Ha!! My friend told me last night that you cant come close to solving

> the problem on your ped until your at least 6 beers deep.

Good thing my FA50 rarely needs attention , as I haven't had a beer in about 20 years .

Re: Garelli revs super high when starting then dies soon after. Air leak?

Having a couple beers and listening to Merle Haggard is standard garage etiquette for me.

I don’t recommend being drunk while working with tools.

P D, I respect your sobriety. For whatever reason, sticking to it for 20 years is dedication. Unless you meant just beer? And now you just hammer bourbon shots while turning wrenches.

Anyhow, where’s that new throttle cable at? The anticipation is killing me.

Re: Garelli revs super high when starting then dies soon after. Air leak?

> Papa _ Wrote:

> -------------------------------------------------------

> Having a couple beers and listening to Merle Haggard is standard garage

> etiquette for me.

>

> I don’t recommend being drunk while working with tools.

>

> P D, I respect your sobriety. For whatever reason, sticking to it for 20

> years is dedication. Unless you meant just beer? And now you just hammer

> bourbon shots while turning wrenches.

I have had some alcohol in the last 20 or so years .

I have a few bottles of wine left from the mid '80s , stored in a cool dark place .

We drink a little wine maybe once a year or two .

And , I have a bottle of Armenian brandy that'll clean your pipes and curl yer toes .

Most that try it don't need any more than a shot and a lot not even that much . ;)

Re: Garelli revs super high when starting then dies soon after. Air leak?

> Aaron Turek Wrote:

> -------------------------------------------------------

> Honkycat - You're on to something - it needs to be getting fuel and air

> and nothing is changing when I mess with the throttle. my cable and

> throttle feel pretty rusty and crunchy. I think something is caught

> open. I ordered a new cable yesterday assuming my slide is stuck open

> due to a shit cable.

>

> However - lets assume it is stuck open and that is why its reving super

> high.. why is dying at full throttle?

Sometimes a problem can be caused by more than one fault. The motor is using more fuel @ wot than will flow to carb. Gas cap not venting, petcock passages/screens plugged, restricted fuel line, dirty screen/filter on carb, float valve not working/partially plugged, fuel level not high enough in carb. etc,

Re: Garelli revs super high when starting then dies soon after. Air leak?

> Papa _ Wrote:

> -------------------------------------------------------

> I don’t recommend being drunk while working with tools.

You're supposed to wait until you're done with the tools and then drink before the test ride.

Re: Garelli revs super high when starting then dies soon after. Air leak?

Honkycat - Treats says it will be tomorrow. And if shit at work is as slow as it was today, I'll have plenty of time. despite the cold temps and 8 inches of snow that we got on Monday that refuses to go way (welcome to Wisconsin).

P D - Armenian brandy sounds like something that could make me go blind upon drinking it. Respect.

Live evil - I can agree that numerous things could be happening. Plan tomorrow is get the new cable on and check that float bowl.

Re: Garelli revs super high when starting then dies soon after. Air leak?

> Aaron Turek Wrote:

> -------------------------------------------------------

> Honkycat - Treats says it will be tomorrow. And if shit at work is as

> slow as it was today, I'll have plenty of time. despite the cold temps

> and 8 inches of snow that we got on Monday that refuses to go way

> (welcome to Wisconsin).

>

> P D - Armenian brandy sounds like something that could make me go blind

> upon drinking it. Respect.

>

> Live evil - I can agree that numerous things could be happening. Plan

> tomorrow is get the new cable on and check that float bowl.

Check the flow of gas to the carb. Pull hose off of carb open petcock and observe flow of fuel into catch can. If flow is good then go on down to the carb screen/float. (edited)

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