Leaky SUs where to buy rebuild

[Zitch]

Guys,

Thanks for all the advice so far!! But since putting the Tr4 in the Garage It has smelled of Gas. My wife wants the car out. I opened the trunk didn't see/smell any leaks by the gas tank, but if I open the bonnet I notices quite a smell. I also noticed a drip of fuel from the bottom of each carb. So i clamped off the fuel line and pulled the SU Carbs.

Now I need to reseal them, which place is the fastest, best, cheapest to get SU carb rebuild kits from?
I'm used to drill down websites to buy auto parts from. These catalog based part sites is like reading old VCR/Stereo instructions.

I assume I need just the gasket set, not all the jets needles etc.

As you can see the bottom of both carbs are wet with fuel.

Bottom of front carb:

1 - leaky seal
2- Leaky jet?
3- missing bushing or wrong pin?

bottom of Back carb:

Just some seals and gromets? Would I need new springs they look pretty rusty and old?

Let me know your opinion.

Zitch

 

[TR4nut]

Sounds like your jets are leaking, pretty common ailment especially if the car sat long. Plenty of kits available from Moss, TRF, VB - for specialized service I highly recommend Joe Curto, https://www.joecurto.com

Joe can rebuild them for you but also will sell just the rebuild kits if you want to fix it yourself.

 

[martx-5]

Most kits that you buy will generally include the jets, as they are a part that does wear. Also, check the throttle shafts and housing where they go through as they are prone to wear also. Carbs with worn throttle shafts are impossible to tune properly.

 

[TR3driver]

As usual, there are a lot of different levels. While there is certainly nothing wrong with a full rebuild, it isn't required every time. If the carbs are in good condition otherwise and you just want to stop the drip from the jets, you can replace just the jet seals with ordinary Buna-N O-rings (size -010).

Moss sells them for $1.20 each, but I just grabbed them from the kit I got at HF. This isn't the same kit, but should do:
https://www.harborfreight.com/225-piece-nitrile-o-ring-assortment-67677.html

Or you might even find them at the local hardware store, but be sure to get Buna-N (aka nitrile rubber) or one of the other materials that is compatible with E10. EPDM (which is probably the most common material for plumbing) is not compatible and will fail quickly.

In my experience, the O-rings last a lot longer than the original cork seals; but of course that depends on a lot of things like how often you use the choke. I've never had the cork last more than about 2 years of pulling the choke 3 or 4 times a day; the O-rings from Moss went over 5 years and even then I only changed them because it seemed like the thing to do (moving the carbs from one car to another).

Polishing the surface of the jet will help the seals last longer (and the choke work easier), too. Just some old fashioned white toothpaste and your fingers will do (but be sure to clean them thoroughly afterwards).

 

[Zitch]

updated with pics of the Carb leaks, let me know what you think

 

[apbos]

I found that when looking for rebuild kits for the SU, that with the shipping finding them on EBay in the UK net the best price for two.
Paul

 

[sail]

I did a full kit in my ZS carbs with the one page instructions that came with them. Wouldn't think your SU's would be much more complicated. Kinda fun.

 

[Rhodyspit75]

Joe Cutro will sell you as much or as little as you want. Unless you are real tight for money, I would go right through them. From the pictures it looks they haven't been done in a while. I have done Zenith and SU's and the SU's are easier.

 

[TR3driver]

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[TR3driver]

Hmm, not sure. Normally when the jets leak, you only see fuel on the bottom part of the jet, but there will actually be a drop hanging off there. Likewise when the float bowl seal leaks, the bottom of the bolt/stud will be wet and not much else. But your photo looks like it is wet higher up, like at the big nut that holds the jet housing (above the spring), so I'm not sure what is going on there.

However, the float bowl seals are clearly past their prime, so I'd go ahead and do all the gaskets (gasket set) at least. Then maybe you can get a better idea of where it is leaking.

The #3 joint looks normal from what I can see; it is designed to have a substantial amount of lost motion so the hole in the lever is several times larger than the pin. What it does is allow the fast idle cam to be activated by some amount before the jet starts to move. You'll probably have to take it apart to judge if it is worn (either pin or hole in lever not round). But it's not likely to be causing a problem. Until it breaks (which I've never seen happen), it just gives you more fast idle action before the mixture starts to change.

Are those the right carbs? I thought all the later carbs used bolts to mount the float bowls, only early TR3 used the studs.

 

[LarryK]

Zilch:

PM sent!!

 

[Zitch]

Are those the right carbs? I thought all the later carbs used bolts to mount the float bowls, only early TR3 used the studs.

It was on my newly purchased 63 tr4, I couldn't tell you if someone before me changed them out.

I can get a picture of the top of the carbs if that would help.

 

[TR4eh]

Welcome to the weird wonderful world of TR4s, Zitch.

 

[mrv8q]

In my experience, the O-rings last a lot longer than the original cork seals; but of course that depends on a lot of things like how often you use the choke. I've never had the cork last more than about 2 years of pulling the choke 3 or 4 times a day; the
O-rings from Moss went over 5 years and even then I only changed them because it seemed like the thing to do.

Funny, just this afternoon I was looking at the cork seals on my '3A, doing a little preventative maintenance on the car for a drive tomorrow. I had Chester at SUcarbs.com go through them in the spring of 2009, so they've held up nicely. Again, the car is only excercised once or twice a month. When the seals do start to weep, I'll put in the BUNA seals.

On my car, I got most of the gas smell/ weeping from the mechanical fuel pump inlet. Not sure if you're running the original or Facet electrical pump, but a couple of those HF BUNA seals did wonders for my weeping fuel pump, and the lack of gas smell in the garage.

When working on the carbs, I used a golf tee in the fuel line with a small hose clamp to seal it, to shut off the gas. (That was a tip from either Andy or Geo Hahn). Imperative to keep the females in your household agreeable, especially to your LBC!.

 

[MDCanaday]

Dont forget to try the old mad dog's trick on old throttle shafts.simply build up the shaft with metal bonding epoxy. (where its worn)
Then smooth it up to a perfect fit of your old bushings.Lube it with teflon grease and go back together.Quick , cheap and EFFECTIVE!
MD

 

[vivdownunder]

Zilch, you'll most likely have the right SU carbies on your car as the banjo bolt method of attaching the bowls was changed to studs back in 1958. Reason being the banjo bolts tended to spin the rubber grommets and scuff the flat sealing surfaces, causing premature failure.

Studs threaded into the carby body were an improvement in that only the nut on the bottom rotated. Both applications use the same grommets.

Viv

 

[SteveBones]

Regarding the studs for the float bowls, I have the same set up on my 1962 TR4 with a 16xxx serial number so my set up matches yours. My engine and carbs are believed to be original.

On a side note, my TR3A has the bolts. The carbs came with the car but were not mounted when purchased and needed to be rebuilt. Not sure why and when SU's made the switch from one set up to the other.

It was on my newly purchased 63 tr4, I couldn't tell you if someone before me changed them out.

I can get a picture of the top of the carbs if that would help.

 

[SteveBones]

Checking in to see how things went with the rebuild. I just finished rebuilding the carbs on my TR4 this last weekend. I was busy with the rebuild and not checking the website so just now checking in on this.

I ended up replacing the gaskets with the Moss kit that included gaskets and the cork seals. I would say that the leaking is tied to usage vs time between replacement. o The TR4 I have I do not drive as often as I should......once or twice per month......the carbs were leak free for 10 plus years.

Next time I have to rebuild, I would like to try using the O-rings. I also replaced one of the throttle shafts to correct something I did from the previous rebuild.

The one benefit of getting the more complete SU rebuilt kit is the really helpful directions that are provided. The directions included:

1) Step by step directions on how to disassemble
2) Multiple exploded diagrams of various areas of the carbs
3) Step by step directions on reassembly
4) Very helpful instructions on how to set up and tune the carbs correctly. This included centralizing the jet and also setting the jets for the correct fuel mixture. The SU carb rebuilt kit I purchased from Moss for about $120.

I hope your rebuild went well.

Steve

 

[glemon]

Couple of things to add, I agree with what Randall said about the o-ring seals, I have had better luck with rubber, I have also been able to purchase individual O-rings in a wide variety of sizes at my local NAPA store. The various vendors "carb repair kits" can vary quite a bit in content, sometimes they have a pretty good list of what is included, sometimes not so much, but you can pick the kit that fits your needs if you shop around and do your homework. Also don't forget about Burlen Fuel Systems in the UK, they are the successor to SU and for most carbs sell individual components, a range of needles, a simple gasket set, and a more complete carb rebuild kit. I think this is your carb, but double check the number. https://www.sucarb.co.uk/CarbEssentials.aspx?ProductId=10122

 

[MDCanaday]

The little trick with the cork seals is to use a silicone grease called sillglide from NAPA
gas dosent eat it up quickly and it lubes the cork for a good long time(5 years +)
MD