Carbuerator keeps vibrating loose

[grandpa2390]

I put the carbuerator on and handtightened as tight as I could (without stripping it) and whenever i start the motor, the vibrations cause the carbuerator to shake loose. My motor will die while riding it as if it is not getting any fuel, but it starts up again immediately once i get some speed. But I am guessing the first possible solution would be to get the carbuerator to stop sliding. Any recommendations? If I still have that problem after the carbuerator stops rattling off, my only guess would be i need to perfect my choking technique. Reaching down and adjusting the choke while still riding. If anyone knows of anything that may be the cause of the engine dieing feel free to recommend. the Carbuerator does not slide completely off, but it slides a cm or 2 from where i put it.

[2door]

Grandpa,
You'll need to seal the carburetor to the intake with a good quality silicone sealer. On either an aluminum or steel intake I use course sandcloth and rough up the surface so the silicone can get a good 'grip'. Use your finger to smear the silicone inside the throat of the carb to fill the gaps and onto the manifold then slide the carb on until it seats. Allow the silicone to set up before trying to run the engine. Make sure not to overdo applying the silicone so it doesn't get into the carburetor or engine. You want just enough to seal and adhere the carb securely. If you haven't done it, you need to also seal the gasket area of the intake manifold where it attaches to the cylinder.
You engine is probably dying from excess air causing an over lean condition. That is caused by the bad seal around the intake and the carb throat. I like Permatex Black, silicone sealer/adhesive for all sealing.
Tom

[grandpa2390]

I don't have the means right now to do all of that, would readjusting the mixture screw perhaps solve the problem? of the mixture being too lean?

[mekano]

If your carb is rattling off: maybe change the china bolt and nut to better ones and tighten real hard?

[BarelyAWake]

Well, that's not a fuel/air mix screw (I wish it was) - that's just the idle adjustment. These carbs fuel/air mix is adjusted by moving the clip on the needle inside the carb - clip up for leaner and down for richer.

BUT - I'd lay looong odds that your mixture problem is from air leakage caused by your carb not being seated properly like Tom said - I wouldn't mess with the mix till ya get that sorted

[2door]

Originally Posted by mekano

If your carb is rattling off: maybe change the china bolt and nut to better ones and tighten real hard?

Be very cautious of this advice. Overtightening of the carburetor clamp can break the taps off the carburetor which will require replacement. If your intake is cast aluminum it can also break. There is no good 'fix' for a broken carb.
Do it right. Seal the carburetor to the intake and tighten the screw enough to hold it securely in place until the silicone sets.
Tom

[grandpa2390]

I am going to go your way 2door. Can you send me pictures explaining what you are talking about.

[mekano]

Originally Posted by 2door

Be very cautious of this advice. Overtightening of the carburetor clamp can break the taps off the carburetor which will require replacement. If your intake is cast aluminum it can also break. There is no good 'fix' for a broken carb.
Do it right. Seal the carburetor to the intake and tighten the screw enough to hold it securely in place until the silicone sets.
Tom

I have never experienced this tap break off or intake collapse.
Maybe I tightened it just right? Anyway, be careful, theese things are not made of the best material.

[Norman]

look a this for some info on mounting the carb to the intake manifold I think the info your looking for is on page 2.


http://motorbicycling.com/f39/motori...build-302.html

[corgi1]

Is there an o/ring in the neck of the carb?