2004 Aprilia Mojito Custom 50 Intake Manifold

Hi all,

I recently bought a 2004 Mojito Custom for my daughter (she loves retro-look scooters) as a non-runner, and I've been going through it over the last few days trying to figure out why it won't start. It's the early series (1999-2004) it seems, and I believe it has a Piaggio engine.

I am a 4-stroke guy, so I know my way around a bike a fair bit, and started by making sure I have a good spark, fresh battery, fresh fuel. Fuel is not being dragged up from the tank, and the pipe feeding the carb was dry as a bone, so a new vacuum fuel pump is inbound already. So whilst I wait for it, I cable-tied a custom built gravity-fed fuel tank to the rear frame (read: large syringe with no plunger and some fuel hose ) however, no bueno, fuel still does not seem to be entering the cylinder. I'm pretty sure I have decent compression, I can hear the vacuum pump diaphragm going when I crank the motor over, at any rate. I have cleaned the throttle slide, and it almost fired after a bit of carb cleaner went through it. Fuel also leaked out of the carb mouth when I removed the carb, so it's getting in there from my very Heath Robinson fuel tank.

An old mate who has repaired a lot of SR50's back in the day told me to check the inlet manifold, as they perish and split, and 9/10 times he had SRs that won't start, it's due to a split inlet letting too much air in, and no fuel due to a lack of negative pressure through the carb.
On closer inspection, it seems that the flange plate that bolts to the carb has mostly parted company with the rest of the intake, so a replacement is needed. Probably all as a result of the previous owner running no airbox (yes, I know, I know....) and the carb flapping about largely unsupported. The standard airbox is ready and waiting!

But sadly, as part AP3ABA000062 is discontinued, I have had to order a second-hand one with reeds from an eBay breaker in the hope it works for a while at least.

If that doesn't work, or dies eventually, I am left with the same issue of that part being very rare, or a couple of hundred £'s from certain parts vendors.

So my question is this: has anyone else here found a currently stocked/produced replacement intake, or, has anyone successfully swapped it out with a newer (2004 - 2010 series) straight intake manifold and another carb?

If so, I would greatly appreciate any help or information, please!

 

In the scooter world it's very old. check the reed petals to make sure of no cracks or not closeing properly. I'm sure any piaggio 50cc inlet manifold will fit. Just go through the usual stuff, new spark plug etc.

 

Yeah, she is pretty old! I'll get the reeds out as soon as my new security allen key bits arrive, as that's the last bit to check.

Looking at other Piaggio manifolds, they don't seem to have the flange plate to bolt the carb to, so suggestions on a replacement carb welcome if I have to fit a non-stock manifold.

 

Early Piaggio's had an alloy flange but later are all black, still have the alloy flange under the rubber coating.

 

Yeah, this one has a flange at both ends. Attached some pics, hope they help.


The carb-side flange was barely hanging on, it's so perished. The whole thing lines the carb up to the airbox, and I'd like to retain that, to save messing about with jetting etc required for an aftermarket item.

 

That looks like the minerelli engine to me, not Piaggio !

 

Okay, I wasn't certain on that, but it's helpful to know my best guess was wrong! How can you tell?

 

Oil pump next to inlet manifold and it's 4 bolt, Piaggio is a 2 bolt manifold. You are correct on saying spares are going to be a problem ! I'll have a look round for you.

 

Aah, thanks for the clear explanation! You are a scholar and a Gent, Marsh!

 

Have a look at this on ebay. 275126964254. or this 303702335691. they look similer ish !

 

Thanks, I'll have a look!