TR4/4A TR4 Stromberg Carb Question ?

[joejoecat]

Started my TR4 this morning and noticed gas dripping. Popped the hood and both carbs were leaking gas at the same point at the adjusting screw . I never touched the carbs and this has never happened before. I thought I may have flooded them ,started the car and ran it for a couple of minutes still leaking.Any thoughts ??? Thanks in advance

 

[DrEntropy]

If they've not been gone thru recently they could have older o-rings and seals which have either dried out finally, or have been melted because they were subjected to ethanol being added to the gasoline... Those are about the only things I can think of to cause "spontaneous" leaking.

 

[joejoecat]

Doc,I haven't used any ethanol gas . They are leaking from the fitting that the adjusting screw goes into. Is there an o-ring under there ?

 

[DrEntropy]

Which carbs are on the thing? HS6 SU's? If we're talkin' the mixture adlusters there's (supposed to be) a cork seal. The only other adjusting screws are external and shouldn't have any exposure to fuel. It may be that the needle/seat in the float bowls are "fuzzed up" and need cleaning, too. Did it sit for any time before this started?

 

[TR4]

There are O-rings that you need to check. See Moss parts 25 and 27 in this link https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29128

 

[DrEntropy]

Profile indicates '64 TR4, has it had Strommies fitted later? :shocked:

 

[tdskip]

My old spit did that all of a sudden (well, after being stored for a couple of months). Slightly different unit than yours, but it was the o-ring and a simple fix.

Doc, my '64 TR4 has Strombergs as well.

 

[joejoecat]

They are Stromberg 175-cd carbs . I just ordered the gasket kit which contain the O-rings from Moss.Any Tricks in replacing the O-rings ? Thanks for all your help.

 

[TR4]

I recommend counting the number of rotations it takes to completely run the adjustment screw up into the carb from where they are currently set. That will then give you the setting when you replace the O-rings. Fully run in the jet and back them off that number of rotations you counted to get you back to where you had them before replacing the O-rings.

You will also need to center the jets so the metering needle rises and falls freely. That effort is a lot easier when the carbs are off the car but I have done it with them mounted.

My TR4 had the same issue when I first bought it and a complete rebuild of the carbs was my first effort to get the car running again. I got a rebuild manual for Strombergs that gave a step by step order. I had no auto repair experience before and they work great now.

 

[trrdster2000]

joejoecat, I wish you had ordered the little kit for centering the jet, it can be a real bear on this carb. On some of the older ones you have to tighen the top screws in a certain order to get the piston to move freely. When you put it back together use some fine oil not only on the 'O' rings but on the threads as well, be sure to clean up the threads with a fine wire brush. You can do this all on the car, but I would go with taking them off and getting a good clean up on both.

Wayne

 

[DrEntropy]

Ah. As the others have suggested, bench the units and go right through 'em. If you just replace that O-ring, you will certainly start seeing othere bits in there fail shortly after. Get all the grief over with at once. :wink:

The kits vary in quality as well. The only source I've used for years is Joe Curto. His are the OEM replacement kits, very comprehensive. Lately Moss has been improving their track record with regard to "lowest bidder" vs. "the right stuff" so it'll probably be fine.

Read the proceedure, follow the suggestions and they'll take you thru it step-by-each. Any questions or confusion, post relevant info here and we'll try to straighten it out. :thumbsup:

 

[TR4nut]

I've changed out the o-rings on these carbs a few times, no real tricks here I think, but I agree its best done with the carbs off the car, drop the bowl to clean things out.

I disagree a bit on the jet centering, as I haven't had a problem (maybe just blind luck). I just found that the jet can be centered by moving the piston up and down while gradually tightening up the bottom adjusting screw. Get it tightened, make sure there is no drag, then set jet height and you should be good to go.

Randy

 

[joejoecat]

Just thought I would give you guys an update.I received the gasket kits from Moss today . I didn't take the carbs off the car I just took out the jet assembly and replaced the 3 o-rings in each assembly put it back together no more leaking gas. I'm not sure the carbs are adjusted properly but it is ideling at about 700 to 800 RMP's. That's down from about 1200 before.Took it out for a spin tonight and it seems to run great,so I don't think I'll monkey with any more just drive it. Thanks for your support.