No idle and general Q&A

Hi, I’m a new vintage moped owner. I picked up my bike yesterday and I’m very happy - though slightly intimidated by it. I’ve never ridden a bike this old. I’ve had a go and I’m getting the hang of it but I need some help knowing if I’m making mistakes or the bike needs work. I’m only used to modern bikes so it’s all new to me.

I’ll be making the post in a Q and A format so it’s easy for me and others to follow.

First of all I would like help identifying the bike. We know it’s a Fantic Motor but unsure of the model name as it wasn’t documented. As far as the DVLA are concerned it’s an orange Fantic. Which is great as that’s my favourite drink.

Second question is regarding road legality as it is. I’m aware that modern rules don’t apply to old vehicles. This thing has the paperwork to go on the road but no mirrors or indicators make me feel like I stick out as someone who shouldn’t be on the road. I will get mirrors fitted for personal preference. I’m looking here to double check that it is legal to be used as is.

Third question is re the clutch which appears to function as normal when starting. You can pedal as normal with the clutch lever left alone and it will start if you pedal while holding the lever. However when the engine is running the effect of the lever is no different wether it is pulled or not. It accelerates well and bogs down and stalls if you slow down. Is this me being a melon or is something not right? I can’t see the clutch cable moving on top of the engine when pulling the lever.

Last question. The engine won’t idle on the stand with the clutch lever in any position. Or when on the ground at a stop. It has been sitting for a long time but I gave it a run and the carb is clean. I’ve found the choke lever which doesn’t have an effect as far as I can tell.

Thanks in advance for taking the time to read and reply.

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Re: No idle and general Q&Atf

1. It looks to be a Fantic lei

2. Unsure of moped laws in the UK. I’m sure someone else will chime in.

3. The clutch is a starter clutch only and should never be pulled while the bike is running.

4. The idle issue is possibly related to the clutch issue you asked about. The clutch engages fairly low on stock bikes. If it won’t idle or make power down low it won’t have enough power to slip the clutch so pulling the starter lever will make no difference. Also the engine will bog and die before the clutch disengages.

I would focus on getting it to idle.

What kind of carb is in there now? Do you know what jet is in it?

Re: No idle and general Q&A

Never pull the clutch lever when the engine is running. Never.

As stated above, it's a starter lever.

How it works, is while pedaling, the clutch is disengaged from the drive, so there's no resistance. Pulling the lever presses a friction plate against the clutch, which engages the clutch, and the engine spins and fires up.

The basics of the centrifugal clutch, is as you rev it up, spring loaded pads expand, contact a drum, and move the gear that moves the bike.

If you pull the lever while the bike is running, you're forcing the friction disc against a very fast spinning hunk of metal, and all it's doing is wearing out the disc, and making grinding noises, which, if done often enough, will destroy everything clutch related.

The centrifugal clutch is designed to hook up as you go, and unhook up as you slow or stop.

An idle problem could be as simple as turning the idle screw on the carb in till it idles smooth, or rebuilding the carb, an air leak, or, you already messed up the springs and/or friction surfaces and the clutch isn't working properly.

Re: No idle and general Q&A

The SHA carburetor has a passage under the slide that provides mixture at idle, it's small and easy to miss while cleaning.

Re: No idle and general Q&A

Update. I’ve gotten used to riding it now but still having idle problems. I didn’t ride it very far so I don’t think I damaged anything. It will idle on the stand with the choke open and it takes little effort to stop the rear wheel so everything seems free. I’ll get onto cleaning the breather holes as mentioned above. This thing still has all the dirt on it from when it was in Italy. Now does that count as patina?

Re: No idle and general Q&A

Bit confused by some advice I’ve been given. An internet man asked if I replaced the clutch fluid after removing the clutch cover to look for damage. It was bone dry when I took it off and there is no gasket or place to top up. Makes me think it’s not meant to contain oil

Re: No idle and general Q&A

The clutch side should absolutely have oil in it. I'm not sure what model that engine is, but the Morini M1 takes 12oz of 20W Non-Detergent oil according to the wiki. You can cut your own gasket using the cover as a template in a pinch.

Re: No idle and general Q&A

Never mind I don’t know what I’m doing. (edited)

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