TR5/TR250 Starter Box Assembly Leak

[Nose]

My starter box assembly on the carb closest to the firewall was leaking gas. I assumed it was from the gasket. I replaced the only gasket that it requires and it still leaks. it's not leaking through the gasket but from the assembly area. What can I do. The leak stops after the engine runs for a few seconds.

 

[poolboy]

Usually that leak occurs because of one or two things
Inadequate spring tension pressing the hollow disc firmly against the body of the carb...crud build up
Or more common, the float chamber is overfilling and the engine can't keep up with the excess when it's idling...needle valve fouled
There is an obscure 'weep hole' and that's likely where the gas is coming from.

 

[Nose]

My starter box assembly on the carb closest to the firewall was leaking gas. I assumed it was from the gasket. I replaced the only gasket that it requires and it still leaks. it's not leaking through the gasket but from the assembly area. What can I do. The leak stops after the engine runs for a few seconds.

thank you for the reply. I took the entire assembly apart, soaked it in gasoline, cleaned it up best I could, put it back together, and now it leaks just a little at start up, then stops......I think I will take your advice, readjust the floats to make it a little leaner and try it again. Appreciate the help.

 

[Nose]

Usually that leak occurs because of one or two things
Inadequate spring tension pressing the hollow disc firmly against the body of the carb...crud build up
Or more common, the float chamber is overfilling and the engine can't keep up with the excess when it's idling...needle valve fouled
There is an obscure 'weep hole' and that's likely where the gas is coming from.View attachment 91259
View attachment 91260

great pictures, but I don't understand the pic with the paper clip

 

[poolboy]

The paper clip is actually sticking into the otherwise 'obscure' hole.
It's the same hole that is clearly visible in the silhouette picture

 

[poolboy]

Just to be clear...my advice wasn't for you to change the float level................
If the floats are set at the recommended 15 to 17 mm I wouldn't fool with them UNLESS one of their pontoons contains gas and has lost a certain amount of bouyance ......usually overfilling is not the fault of the float though.....most of the time it's the needle valve and sometimes it'll self cleanse of the obstruction or residual varnish from the evaporated gasoline.

 

[Nose]

The paper clip is actually sticking into the otherwise 'obscure' hole.
It's the same hole that is clearly visible in the silhouette picture

Dahhh, thanks...I don't think my hole was that big with my carb. I have the carb where you have to take the piston out of the carb body to adjust the fuel air mixture.

 

[Nose]

Just to be clear...my advice wasn't for you to change the float level................
If the floats are set at the recommended 15 to 17 mm I wouldn't fool with them UNLESS one of their pontoons contains gas and has lost a certain amount of bouyance ......usually overfilling is not the fault of the float though.....most of the time it's the needle valve and sometimes it'll self cleanse of the obstruction or residual varnish from the evaporated gasoline.

ok. I put all new gaskets on the carb, and a new needle valve. I did check the floats when I had it apart and they appeared to be about right.

 

[poolboy]

Dahhh, thanks...I don't think my hole was that big with my carb. I have the carb where you have to take the piston out of the carb body to adjust the fuel air mixture.

Yeah the hole is that size in your carb's starter boxes...they all are.

 

[Nose]

Yeah the hole is that size in your carb's starter boxes...they all are.

Is there a way to eliminate the starter box assembly, the part that actuates the extra gas for the choke. I don't need the choke to start my car. Some Triumph guru worked on my carbs several years ago, changed some of the vacuum, did away with that emission device called the breather valve assembly, and also did something to my bypass valve assembly. When I was taking my carbs apart and cleaning all the different pieces, I noticed that this guru placed a solid metal gasket over the bypass valve opening. I'm assuming this left the bypass valve useless. Whatever reason he did this, my car never started better. I never have to choke my car to start it, not even in cold weather. I have not been able to stop the gas from leaking even though it leaks just at the start up and then stops after a few seconds....

 

[poolboy]

If someone told me they didn't need the choke to start a TR6 engine the first thing in the morning, I'd suspect the float chamber was overfilling...the same reason why the starter box on your carb is leaking.
I'd want to fix that not just because of the leak, but what the excessive fuel might be washing down the cylinder walls, maybe even diluting the motor oil.
Does the oil on the engine dipstick have a gasoline odor ?

 

[Nose]

Poolboy, you have no idea how much i appreciate your advise. I took the carb off and removed and separated the starter box again, stretched the spring a little, put it all back together, took the floats off and checked to make sure they were not bad, set the float to about 15mm, it was about 18mm. So I didn't get the float right the first time, but now I'm good. Just got it all back together, fired it up and no leaks.....I'm sure you know, getting those 4 nuts off the carb manifold is a pain.....glad that's all done....thanks again for your advise...you are appreciated. Peace

 

[Nose]

Now my carburetor nearest the radiator is leaking through the bottom of the jet plug. Any suggestions. The car is running better than ever, if I can just get the leaking to stop.

 

[poolboy]

It could be as simple as cleaning the hole and replacing the O-ring...that is if the leak is just gravity related and an O-ring
It could also be due to an over filling float chamber and the fuel is being forced out.
I'd check those black floats for buoyancy and if they float evenly put them back in and set the height at 17mm.
And when you put the jet back in..remember it sets the richness of the mixture, so if you were happy with the mixture, make sure you get it back in the identical depth from the bridge.

 

[Nose]

Okay I will and thanks for the advice.