Well I guess I’m paying for letting my XK140 sit unused for several months. Today I pulled it off the lift and turned on the ignition and it started right up! But…when I shut it off I smelled gas. Looking under the hood I found that the bottom of both carburetors were wet with gas. Attached is a picture of that area for the carb nearest the firewall. The other carb is leaking in the same place. All of the areas that I’ve put red arrows to are wet.
It would seem that I would need to replace the fiber washers in both areas on both carbs…right? Or is there somewhere else for me to look for the culprit? Never having done this are there any tips/suggestions/warnings anyone could give me?
Also, is this a job I can do while the carbs remain mounted to the engine or am I looking at needing to remove them to accomplish this?
Have you tried tightening up the banjo bolts in question? Sometimes thet can dry out and shrink a bit if thr car has lain idle for some time. I thnk the fibre washers supplied today are more prone to this.
HI Chris,
All of the banjo bolts are higher up than what’s pictured but yes I did check all of the fittings and all are tight. I’m thinking that I will need to remove both of the pictured bolts (I think the one the right is a cap with a fiber washer inside of it - need to check that out). and replace the washers.
Still searching the different forums to see if this has been discussed elsewhere but coming up empty for now. Moss catalog is at the ready!
Thanks!
Chet
I did it just a month ago on my 120, replaced all the fiber gaskets or washers. Probably last did it 15 years ago.
Yes you can do it without taking the carbs off. You have it correct that the brass cap has a little fiber washer in the bottom of it. They are all special BSPP sizes so not something you will find at Ace Hardware, but Moss has them. Don’t forget to clean the check valve in the starting pipe.
I carry an extra set with me, along with a float, in my emergency kit.
Hi Rob. Thanks for your reply! Looking at the Moss catalog online I see they have “Jet Cover” part #AUC-3160 listed as the correct part for that brass cap however there is no mention of a fiber washer included. I don’t see any separate listing for that washer - would you happen to know if that part sold by Moss includes the washer and if not where I might find it?
I’m assuming that I can simply unscrew the second (larger) bolt in my picture and replace the washers shown directly above it, however there is another washer above the bracket that is above it (top arrow in my picture). Would you happen to know how I would get access to that for replacement?
Thanks for your help!
Chet
The left arrow in your picture points to the jet assembly itself. Take care when loosening the big hex nut, as the jet assembly inside is spring loaded with quite a strong spring. It uses a special cork washer held in an alloy cup under the hex head. When replacing you have to hold the assembly up against the spring pressure to get the hex nut started on its thread. Don’t do it up tight straight away, but keep lifting the carb piston and let it drop into the jet assembly to make sure the needle is centred. You want to hear a nice positive clunk as the piston lands. Keep checking as you tighten it up.
Moss used to sell the jet cover washer separately. I wonder if they dropped it. They show it in the rebuild kit.
It is a fiber washer about 0.463" OD x 0.350" ID and about .030" thick.
It fits snug in the cover and needs a large enough ID so it doesn’t touch the jet screw and move it when you screw the cover on.
Burlens or SU Rebuilders in San Diego might have it.
I presume you have BSF wrenches or sockets.
You will probably want to remove the jets, float bowls and starting carb and do everything. When you put it all back, leave everything loose until you get all the parts aligned, then snug everything up finger tight, then go back and tighten everything a little at a time.
Thank you Bob - that’s very helpful! I confirmed just now that Moss does not carry the fiber washer however both SNG (US) and SU Rebuilders do. Shipping of course will cost me a lot more than the part so I will first try to see if I can find fiber washers of the dimensions you kindly provided.
BSF wrenches or sockets? Well…I have the original tool roll that came with my car so I’m hopeful. Would you happen to know which wrench sizes would fit the two hex heads for the jet cover and the float bowl bolt in my picture?
Well…replaced the fiber washers but still leaking (?) Also now the engine won’t start (?). Any idea what I did that would cause it to continue to leak and also cause the engine not to start? I’ve checked all the electrical wires and none are disconnected…engine cranks fine.
The old adage is that if it ain’t spark it’s fuel, and if it ain’t fuel it’s spark.
Can you dribble a little bit of gas in the carb throats or on the air filters and see if it pops?
Chet: on the leak, can it be that you damaged the cork seals when installing? Did you soak them in oil like a full day before installing? In case the big washers at the bottom are fine, and the banjo washers are fine, there should be no possibility of external leaks (i.e. you are sure the leak is not from the float chambers or auxiliary carb). Are the floaters ok?
Are you sure when you turn the engine with a spark plug removed (and please no ignition wire) that there is fuel in the cylinders?
Have you not perhaps touched a cable from the coil while working on the seals?
Thanks Rob and Luis for your suggestions and help. The car started fine before I messed with it. All I did was unscrew the large (float bowl) bolt and replace the washers per Moss parts on both sides of the bowl mount then screwed the bolt back on and tightened it. I didn’t touch the jet cover. No electric connections were touched and are still in place. There is fuel and spark. In fact if I let the car sit for a little while it initially seems to catch but does not start and then just cranks without catching even a little bit. I’ve no idea what I messed up with the removal and replacement of the bolts on the bottom of both carbs…
At any rate I’ve decided to bite the bullet and get the car flat bedded to my mechanic tomorrow. I’ll report back once the issue is diagnosed and fixed in case others run into the same issue.
Turns out both float bowls had small cracks in them thus the reason my changing the fiber washers did not solve the leaks.
I continue to be amazed at the various ways my car finds to challenge me!
All I did was unscrew the large (float bowl) bolt and replace the washers per Moss parts on both sides of the bowl mount then screwed the bolt back on and tightened it. I didn’t touch the jet cover. No electric connections were touched and are still in place. There is fuel and spark. In fact if I let the car sit for a little while it initially seems to catch but does not start and then just cranks without catching even a little bit. I’ve no idea what I messed up with the removal and replacement of the bolts on the bottom of both carbs…