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MG TD TF 1500 - 'Tickler' ? Pins

Whilst waiting on the overflow pipes to arrive, I am concerned about the existence of "tickler" pins(?) on the carbs.
My front carb has a good functioning pin. It is in the up position and returns to position when pressed down. The rear carb has the pin but it is in the down position. I can pull it up with a screwdriver but it immediately falls back down.

Now, the TD is running just fine (albeit the rpm's are a bit high). I heard that epoxy on the pins will prevent leakage from the float chamber. Should I do this? Even with both pins in present locations?

And, finally, why would these be present if they leak before the petrol even gets up to the overflow pipes?

So many questions...thanks in advance!!!

Octagonally stoked...


DaveL
dave lackey

I'm curious about this too. I noticed the same thing whilst working on my carbs.
V.W. Piņa

And both of mine have 'ticklers' ... have read various postings about filling them in... My old Triumph 650 had one, but I used it everytime I started the thing?
gblawson - TD#27667

Look at the where the tickler-pin openings are with respect to the height of the overflow. It must have been some kind of post tramatic stress disorder from WWII that caused the engineers to allow the overflowing gasoline to escape throught tickler-pin openings before it could be redirected to the overflow tubes. Yes, they may be moving free now, but at some point the pins will stick open and you will get gasoline on the exhaust manifold. After a pretty scary episode, our tickler-pins are now epoxied into the lids. We left the brass pins intact for appearance only.

Safety? Fast?
Scott Ashworth - '54 TF
S. R. Ashworth

Dave, If I remember correctly (which my wife says I don't very often) the manual says they are there to break the float loose to check for petrol in the chamber. Good idea gone bad. The pins don't make a tight seal against the bowl lid and because they sit lower than the overflow pipe it will be the first place fuel leaves the chamber if the float is stuck down or the needle isn't sealing. If you decide to seal them, you will want to pull the pin up. It sounds like the spring is gone or the keeper is missing on the one that falls down. It is most likely resting on top of the float all the time and could (not likely) become bound when the float is in a lowered position and cause flooding. Unlike the pin used for lifting the carb piston while tuning, these are not really needed. You can find lids without them, seal the pins or roll the dice and hope it never floods while the motor is hot.

LaVerne
LED DOWNEY

Yikes!
Sooooo, I should epoxy them.

But, do I somehow raise the rear pin before epoxy is applied?

Best regards,

DaveL
dave lackey

Dave,

As LaVerne said, later covers had the pin holes blocked, the boss never drilled out. I found a front cover (whole 'nother story, but rather than assymetrical fuel line banjo mounting points, I decided I needed symetrical ones) with a never drilled boss. I took the rear cover and filled the location where the pin was with JB Weld. Since I never had pins in mine, it was an easy decision to make.

warmly,
dave
Dave Braun

Thanks for all the advice, just not looking for a BBQ under the hood!

Must pick up some epoxy on the way home this evening. then the overflow pipes on Friday night! Less than 72 hours to go before the Great Adventure starts.

The collective knowledge on this board is fantastic!!!
dave lackey

The tickler pins, or rather the holes in the top of the float chambers for them are an extreme fire hazard, and source of unnecessary air pollution. Your float chambers will nearly always evaporate all of the fuel in warm weather from the residual heat from the exhaust manifold. My girl friend couldn't stand the gas fumes on her side of the car, and they went away after fixing this.

I contacted Joe Curto and SU/Burlen on this topic. Later versions had a solid top, and you can buy them. But even used they are very expensive. Burlen suggested that I use Devcon metal putty to fill the hole, and that is what I did. It worked fine, and looks the same color. I removed my pin. It serves no functional purpose for me, since I installed Grosse jets, replacing the needle valves, anyway. I suppose one could epoxy it in place, but better make sure it is in the fully raised position before doing so.

A cautionary note: You MUST have the proper scalloped washer between the lid and the overflow fitting, or air can't flow in/out of the overflow hose as the fuel lever goes up and down. My car didn't and I ran into starvation problems at high RPMs. I guess it won't work as an overflow hose either. This is a salient feature of the SU carbs.
Larry Ayres

Grosse jets ? Never heard of them. Are they a vintage or contemporary tuning gizmo ?
Remo Peter

Grosse Jets is a brand name for a needle valve and seat system which seemed to function better than the standard SU needle valve and seat found in the float bowl covers which along with the float, determines level of the fuel in the float bowl. Recent reports are that the Grosse Jets of the past few years have had underwhelming quality control, and the Grosse Jets tend to stick open, flooding the bowl, raising the level of fuel in the bridge, and running out the over flow tanks.

I continure to use my old Grosse Jets, rather than replace them, given the rumors and observations of others.

warmly,
dave
Dave Braun

Just to clear up one item. My rear carb tickler pin is in the down position. I assume if it has a spring, it is pushing the float down...or the spring is missing?

So, either way, I should just pull up the pin, support it in the up position and glue that sucker down, right?
dave lackey

Dave,
I would, or remove the pin altogether as I did and fill the hole.
Larry
Larry Ayres

Dave, you will want to remove the lid and take the pin out before applying the epoxy. You want to make sure you seal the hole and pin.

Evan Ford - TD 27621

Strange, I've never had gasoline leak out of the tickler pin openings on my carburetors. I find them to be very handy for checking the fuel pump/float function. And then I've never seen anyone demonstrate that a TD exhaust manifold can be hot enough to ignite gasoline. Anybody ever seen the demonstration of extinguishing a lit cigarette by dunking it into gasoline? YMMV, but my tickler pins remain functional and my overflow pipes are as designed.
Bud Krueger

Bud I've seen that trick but the ass that did it was standing beside me at a Conoco tank farm and the butt went into a spill bucket. The ignition happens after the wet fuel turns to vapor and the tempature reaches its flash point. It can and has happened. As long as the floats, the needle and seat and the fuel pump function properly there is no problem. They are however mechanical devices and all mechanical devices will fail eventualy. They make for intresting conversation, but not only are they uneeded they are unsafe.

LaVerne
LaVerne

OK, I admit to being an SU Carb novice. Best I ever did 30 some years ago was by dumb luck repair a leaking carb on a TC. So what is the "purpose" of the tickler pin? Mine seems free and the spring works.

Larry
L Karpman

The original purpose of the tickler pins was to press teh float down to open the needle valve completely so that any debris trapped under the needle would be flushed out. Remember that the fuel available in the 30s, 40s, and 50s was not a clean as the fuel we get today. I am with Bud, I have never had a problem with fuel escaping from the tickler hole. There is a neoprene washer that fits around the pin and should close off the hole when the pin is all the way up. I have found the tickler pin useful in clearing vapor lock bubbles that form under the float, by pushing the float down an forcing the bubble up around it.

The only time that I have had the needles not close off the flow of fuel was after the car had not been driven for a long period and all the fuel had evaportated out of the float bowls, allowing the float lever to drop down so far that the needle would get trapped between the lever and the valve housing. I believe that tis is a common problem unless Gross jets are being used. I cut slots in the back end of the float lever, forming a tab that can be bent down to limit the lever drop such that the needle won't get caught and jam on it. I will send the information on that to Bud to put on his web site.
Cheers - Dave
David DuBois

Gentlemen You are lucky!!!

I have personally seen two TF's and one TD pour fuel out of the tickler pin holes, (due to sunk floats, loose grosse jets, etc.). Luckily, the cars had just been started up, and the manifolds were not yet hot. My second TF (1250) has had a fire due to carb overflow. One of our members, Dell Fruit, burnt up his TF on his first start up after rebuilding due to stuck float.

The manifold is hot enough to exceed the "flash point" of gasoline. ( but it's a random chance wheather at a given instant it will flash), and in addition any spark will set off the vapours in any case.

Ask any insurance company about the source of car fires while driving to see if raw gas and hot manifolds don't cause fires.

I had two VW Bugs burn when the fuel line at the carb pulled out and fuel was pumped aver the engine.

I say plug the pin holes, Dave's gasket is not in the carb rebuild kit, and I doubt that many are left in good shape after 50 plus years. (I have never seen one in allthe carbs I have rebuilt).
Don Harmer

Reactivating an old thread ...

> Any suggestions on a source or a substitute fuel-proof gasket on the tickler pin?

I assume that the gasket on the tickler pin fits tightly over the small end of the pin between the bottom of the float bowl lid and the "C" clip.

Thanks,

Lonnie
TF7211
LM Cook

Even though I have not done so myself, it is a good idea to epoxy the holes for the tickler pins shut from a safety point. Quite frankly, there is no reason to even have the tickler pins in this day and age. The original reason for those pins was to push the floats down in an attempt to flush out debris that may have gotten stuck in the needle valve back in the day when fuel was really quite dirty from the pump. This is not a big problem these days as the fuel we purchase is really quite clean compared to years of yore, and we all have our fuel tanks scrupulously clean and coated to keep rust out of them, don't we? Cheers - Dave
David DuBois

Dave,
You said that you are waiting for the overflow pipes to arrive,,, do you have the "banjo" fitting for attaching to the carbie? If you do, you can get copper pipe (tubing) from your local hardware store and solder it on,,,,

SPW
STEVE WINCZE

Steve, if Dave L is still waiting on his overflow pipes, he has been waiting for almost 6-1/2 years. This is a re activation of an old thread.

Warmly,
Dave
Dave Braun

One of my carb bowl tops, the rear, was replaced back when and it has no tickler pin, the top appears to have no place for a pin. Would this be an after market or did some carbs have no tickler pins? PJ
Paul S Jennings

Later top were made without the tickler pin - see Larry Ayers' post above made on 11 October 2006 at 16:42:48 UK time
Gene Gillam

There is nothing more fun than pressing the tickler pin and listening to the fuel pump start clicking. Very satisfying, from a diagnostic point of view. :)
Steve S

About 8-10 months ago I ran into this when I was rebuilding/reassembling the carbs on my 52 TD.
Like Bud I did not want to do away wit them, for no other reason than they came on the car.
I therefore decided to "correct" the problem.
I made a longer pin, shown with the older pin, the spring and the "C" clip in the first frame. (BTW I have 99 extra "C"clips.)
I also made an extension for the boss on the cover. This is aluminum and is shown in the second frame. I had to drill out the original boss a bit for this to be a press fit. I also used Green Locktite.
This puts the top of the boss above the overflow. Hopefully it should eliminate any issue with raw fuel being dumped since it should flow out the overflow first.
The new "tidkler" is a nice fit in the new boss so it should take some extra pressure to force fuel past the pin.

I now believe I have "Safe" working ticklers but I hae only run the engine once for a short period of time.
More running I home next April.

Jim B.



JA Benjamin

Jim, I surely envy your machining skills and facilities. Bud
Bud Krueger

Jim,
I applaud your effort to resolve this issue - but somehow I think the delivery of fuel under normal pressure form the pump through the jets will overcome the ability of the overflow pipe to pass the fuel sufficiently fast enough to stop it coming out he tickler hole.
Easy way to check is remove the float and turn on the ignition and see what happened - You can put a hose on the pipe to a jar to catch the fuel released.
I would be interested to know the outcome.

Dave said there is a sealing washer on the tickler so that when in the up position, under its spring tension, it will block the vent hole. That would work - but I have to say I have never seen one installed?
If it means my car is safer and functions as intended. I will and have blocked both the tickler holes.
I don't like wasting petrol as it costs more than beer and I don't want my TD to burn cause I did not want it to loose a few points in a concourse event. SU saw the error of their ways and resolved it. That is good enough for me.
If I ever see an MG on fire. I will try my best to put it out with my extinguisher. God forbid that ever happens. With luck, I feel happy it won't be mine.

JM2cW

Rod

R D Jones

With a fuel level high enough to run out the tickler..would the engine be running? Under engineered at the time and perhaps over thought now. Regards, Tom
tm peterson

The only time I have had fuel spurting from the tickler and the overflow tube in the 40 years of having our TD was when the car had sat, undriven for a long enough period of time that the float bowls were completely empty. When the ignition was turned on and fuel pumped into the float bowls and the float jammed against the float lever due to the lever having dropped down too far (and at that time the exhaust manifold was cold). I corrected that problem by adjusting the lower limit of the float lever (see the article, Float Lever Drop Adjustment in the other Tech Articles section of my Homepage at: http://homepages.donobi.net/sufuelpumps/ ). Since then, I have never had any fuel pumped out of the float bowl. As a first action for preventing fuel loss through the tickler button hole, I would suggest that you check the float lever drop adjustment and rectify it as necessary. If you still don't feel comfortable with the tickler set up, you can either remove the button and fill the hole with JB Weld or (if you are concerned with loss of concourse points, just epoxy the button in place. Jim's fix, with some impressive machine work is also a good fix for those with his skills (or access to a machinist who has those skills - Jim, have you thought about making your fix available for an appropriate fee?). The other thing that would minimize the problem, would be to grease the pin well with silicon lubricant, then work JB Weld into the hole around the pin, producing a very close fit that would minimize fuel from coming past the pin in case of overflow.

Quite frankly, I believe that the problem is overblown (now taking cover). I can only think of one reported incident where a car was burned as the result of this situation. It all boils down to how well your car is maintained and your own tolerance for risk is. As I have stated earlier, the main reason for the tickler button was dirty fuel in the early years of our cars and that is no longer a real concern. We have owned and driven (year around) our TD for 40 years and I have only had one incident of the float bowl spewing fuel out around the tickler button and that was cured by adjusting the float lever drop to keep it from jamming against the float after the fuel level in the bowl got excessively low. Cheers - Dave
David DuBois

Back to my original question ...

>> Anyone have a suggestion for the neoprene washer that DaveDuB described for the tickler?

An O-ring would be perfect. But I can make two washers if I can find soft fuel-proof material.

Jim - if my car burns up, I can't say that I wasn't warned!

Thanks,

Lonnie
TF7211
LM Cook

Lonnie - you have e-mail. Cheers - Dave
David DuBois

I made gaskets for my ticklers.

Dave DuBois sent me a photo of the tickler pin, spring and neoprene washer from Burlen Fuel Systems in England, P/N WZX 1105. He also said that he had seen the gasket in the tickler package from Moss, P/N 375-045. However, the gasket was not included in the two packs of ticklers that I recently bought from Moss.

I bought a 2" neoprene washer at Ace Hardware. I punched a hole in it with the smallest tip of my leather punch. Then I centered the new hole in the opening of a paper punch. The paper punch popped out a round washer with a hole in the middle. The small hole seals tightly against the small end shaft of the tickler.

I flattened any burrs that may be on the opening for the tickler under the float bowl dome with an emery board so that they won't cut the neoprene.

First I made a small size washer, but didn't use it:
The washers that I made with a standard size paper punch produced a washer that is probably very near the diameter of the original washer. A small stainless steel washer goes between the neoprene washer and the circlip.

Next I made a larger diameter washer which I used.
I was afraid that the small neoprene might fail, so I made two more with a larger diameter paper punch. I backed up the neoprene with an aluminum reinforcing plate for a 1/8" pop rivet.

I'll drop a piece of neoprene into a jar of gasoline to see how well it survives.

So far, no leaks from the tickler holes on my carbs that I just finished rebuilding.

FYI - The tip of the tickler extends into the bowl just enough to interfer with the setup rod for adjusting float drop. Remove the tickler; adjust the float; reinstall the tickler.

PHOTO:
> Top center: regular-size-hole paper punch that I did not use to make the gaskets.
> Top right corner: large-hole paper punch with that I used to make the gaskets.
> Float bowl dome on left has tickler, gasket, and backer plate installed.
> Center: tickler, spring, shop-made gasket, aluminum backer plate for 1/8" poprivet; circlip
> Lower left and lower center: rubber neoprene after and before punching. Small hole at 11:00 o'clock was made with leather punch. Two small holes at 7:00 o'clock appear to be near the size of the original gaskets. The four large holes are the size of the gaskets that I used.
> Leather punch in lower right corner with smallest tip in position.

Lonnie
TF7211


LM Cook

PHOTO:
Gasket and backer plate on both float bowl lids.

Lonnie
TF7211


LM Cook

PHOTO:
Tickler parts by Dave DuBois.

Lonnie
TF7211


LM Cook

Well that looks good and I would think resolve the issue of gas (petrol) flowing out of our tickler Lonnie. Nice job.

Rod
R D Jones

This thread was discussed between 11/10/2006 and 08/03/2014

MG TD TF 1500 index

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