Troubles with F5-A

[Brad_Alto]

Hehe, yeah i was driving it today, will it go worse without a 2nd barrel, i had some rubber band acting as a spring but when i flattened it, it died. Should altos run without the 2nd barrel? is it doing the carbie any harm. when i start it up when its dead cold starts first kik when i start it when its hot it blows black smoke and chuggs. i thought turning down the mixture?
brad

[Josh]

You'll have far less top-end power running on the primary throttle alone. The secondary will make the engine die if it is opened suddenly. It needs to be opened gradually and at high RPM - hence the vacuum diaphragm setup.

[Brad_Alto]

Hey josh,
thanks for the info, what you explained makes a lot of sense whereabouts do i pick one of these vacuum diaphragm and the 2nd barrel from?
brad

[Josh]

You should be able to pick up a replacement vacuum diaphragm to connect to the secondary throttle linkage from a spare parts retailer. Steer well-clear of SuperCheap - I've already hunted around through their supplier's catalogue and come up with very little, and you're not likely to come across any trained spare parts assistants there anyway. Give somewhere like AutoPro a go, and try to jot down any numerical markings on the carby to help them out.

[Brayden]

A carby kit should be around $75 but the vacuum pot is an expensive prick - cheapest I could find one was about $90

[truder44]

Brayden
Where can I get a carby kit from? When I asked the local Suzuki dealer they said the F5A / F8B carby kits were discontinued.

[Josh]

Maybe at a Genuine Parts level, but otherwise that is not true. Fuel Miser still manufacter two carby kits for F5A/F8B carburettors, although I am not sure which carby is which. Both of the following are recommended for the MightyBoy:

- Fuel Miser MS-504
(suits MS2 24/32 DIDS Carby)

- Fuel Miser MS-506
(suits MS1 79000 Carby)

[truder44]

Thanks Josh

Apparently F5A is MS2 carby and takes MS-504 and
F8B is MS1 carby and takes MS-506

[Josh]

Thanks for clarifying that Truder!

The Fuel Miser catalogue was pretty ambiguous about the issue when I last checked, and the truth of the matter has eluded me for some time!

[Colin]

the vacume diaphrams are the same as some sigma/magna ones easy ti get from wreckers

[Josh]

Oh, great info Col! Cheers!