Sticky twin carb's.

Previously wrote:

Hello All,

The twin carb's on my 54' Domi racer are causing a few problems. The slides close easily when the engine is not running. With the engine running, any light opening of the throttle causes them to stick open.

My first plan of attack when home next is to replace the throttle cables. Any other suggestions would be appreciated.

Cheers

Rob Lutman

can you see the slides staying open or are you assuming they do because the revs rise,if they do snap shut yet still you experience rev rise it could be due wear to the engine side of the slide or tofree play between slide and carb body,causinga weak mixture,or even a poor seal to the carb flange, if they dont snap shut check yourslide spring tension after ensuring the cables are free.if you have a two into one junction box for the cables they can stick internally too and can be difficult to get to operate smoothly, i have a feeling that oil on nylon doesnot always lubricate well and can cause binding, the internal disc of that unit is commonly made of nylon.

Previously wrote:

Hello All,

The twin carb's on my 54' Domi racer are causing a few problems. The slides close easily when the engine is not running. With the engine running, any light opening of the throttle causes them to stick open.

My first plan of attack when home next is to replace the throttle cables. Any other suggestions would be appreciated.

Cheers

Rob Lutman

I have recently had a badly sticking throttle and it has been caused by ethanol in the petrol attacking a petrol tank sealant. On combustion it lefta very sticky residue on the engine side of the throttle slide plus more in the manifold and the throat of the carb.

I had also had some smoking on starting for some days before the throttle stuck.The remaining petrol in my tank had changed to a yellow colour.

A friend has the same issue but possibly caused by the use of a petrol additive.

The "Fuel" article in the June issue of Roaholder is worth reading.

Ihope that your sticking is cured by new throttle cables - I thought new routing of the cables was all I needed.

Iain

Previously wrote:

Previously wrote:

Hello All,

The twin carb's on my 54' Domi racer are causing a few problems. The slides close easily when the engine is not running. With the engine running, any light opening of the throttle causes them to stick open.

My first plan of attack when home next is to replace the throttle cables. Any other suggestions would be appreciated.

Cheers

Rob Lutman

I have recently had a badly sticking throttle and it has been caused by ethanol in the petrol attacking a petrol tank sealant. On combustion it lefta very sticky residue on the engine side of the throttle slide plus more in the manifold and the throat of the carb.

I had also had some smoking on starting for some days before the throttle stuck.The remaining petrol in my tank had changed to a yellow colour.

A friend has the same issue but possibly caused by the use of a petrol additive.

The "Fuel" article in the June issue of Roaholder is worth reading.

Ihope that your sticking is cured by new throttle cables - I thought new routing of the cables was all I needed.

Iain

thats interesting and worrying too , unleaded fule is attacking fibre glass, its attacking valve seats, when left for longer periods of time it allows corrosion in the carbs, maybe anything being stored for a period should have a two stroke mix added to the tank and the engine run on it to coat the internals in an oily residue to prolong its life, like the Redex used to .