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MG TD TF 1500 - Sticky Tickler Pin

Hello,

I have a 51 TD that has a tickler pin that sticks. To temporarily remedy this, I have to tap the pin with a screwdriver before I drive it to get it to function properly.

I am looking for some advice on how to remedy this long term. I have heard that switching to Grose jets may help the situation.

Has anyone run into this before? What are your thoughts on switching to the Grose jets? Should I try something else first?

Once again, I really appreciate the advice.

Regards,
Steve
SC Christian

Steve, not exactly sure what you mean. Do you use the tickler pins (push them down) to start the car? Or do you mean that the float or needle valve is sticking open, and you have to push the pin down to flush it out? A few more specifics would help. You really shouldn't need to use the tickler pins, and they are very often sealed shut since gasoline spews out around them if a float sticks. George
George Butz

Hi George

I hope I am using the right terminology. I believe my problem lies with float or needle valve sticking open..

Here is the situation.... Once I turn the key on, the fuel pump kicks on and starts to fill the bowls. On one carb, I can see the brass pin rise up (life is good). On the other carb the pin will just stay down. If I dont gently tap it with the screwdriver, it will eventually start to send gas to the overflow pipe and on to the floor. Once I tap it the pin will unstick itself and I will be good for a day.

You said that I shouldnt need the tickler pins. What is the best way to seal this.

Thanks,
Steve
SC Christian

The tickler pins ride on the top of the float, and are one indicator that the float is rising. And you can depress a tickler to see if your fuel pump is working. But the tickler pins are only an indicator that the float bowl is filling, and have nothing to do with shutting off the flow of gas; it is unlikely that the pins are sticking. The needle valve and seat are not closing tightly on your carb, and you ought to check, clean and/or replace them. Also, lift out the float and clean out any rust or debris in the bottom of the float chamber, and the filters in the pump and fuel inlet line (there is usually an accumulation of fine rust). I have had poor luck with the Grose valve, and prefer the Viton-tipped stock needle and seat.

Also check the float level carefully, which should be .102 to .200" below the bridge (don't bother with the rod method). There is much info in the archives on the subject.

Tom
t lange

Tom,

I've been telling people .120 to .200 below the bridge.

warmly,
dave
Dave Braun

Dave - you are, as almost always, right - fat fingers and dyslexia...

.120 to .200 it is.

Tom
t lange

My tickler pins are sprung loaded in the "up" position and have small fibre washers which prevent fuel seepage when closed in the fully up position They do not gently rest on the top of the floats.

I have used Gross jets for years. They seem to do a better job of fuel control than the old tapered pin type but recently some of the new ones have lost a bit of "quality control" and have, on a few occassions, stuck open.

There is no connection between the use of Gross jets and the use of the tickler pins. They are separate items, with separate jobs to do.
Geoff Love

Steve - I believe that the problem you are experiencing is not a case of the tickler of the needle valve itself that is sticking. Rather, the float lever is dropping too far when the fuel in the float bowl evaporates after the car has sat for several days. When this happens, the needle in the needle valve becomes trapped because the angle between it and the float lever becomes too small. You can see this for yourself by removing the float bowl lid and hold it in its normal operating position, the try lifting the lever with your finger. For more information on this situation and how to correct it, see the article, Float Lever Drop Adjustment in the Other Tech Articles on my web site at: http://homepages.donobi.net/sufuelpumps/. Note, this is not the normal float adjustment, it is a totally different situation. Switching to Gross jets will eliminate this problem, but the quality of today's Gross jets is not what it used to be and other problems can occur with them. Cheers - Dave
David DuBois

Thanks everyone. I really appreciate the support this group has given me. I apologize if my questions are rudimentary. My father has recently handed down the TD to me and even though I have known this car most of my life, I havent had a real chance to work on it until now. I hope to learn much from this group and maybe someday be able to answer a few questions as well.

I will check and clean the mentioned parts above this weekend. I will hold off on the Grose jets for now. I will let you know the results.

Respectfully,
Steve
SC Christian

steve, i'm going to go with how i read your description..not saying it's right..just how i read it. if the tickler pins "ride up" as the float bowl fills...it sounds to me like the tickler pins are installed wrong and are riding on the float and could, indeed, be causing the float to hang up. when i got my car they were a collection of incorrect and cobbled parts used to make up my tickler pins and it was all wrong. the pin sat on the float rather than being held up by spring pressure, as geoff explained above. i kept the tickler pins in my float bowl... i am not a show car guy, but this is how my car was built so i will leave it for the next care taker of this car to decide whether he/she wants to keep them or chuck them. if the tickler pin is not causing the float to hang up there are a few very good ideas posted on this thread as to other possible causes and solutions.
to answer your second question steve..i have read here that several folks have had good success sealing the tickler pin hole with J.B. Weld. good luck. regards, tom
tom peterson

It sounds as though you are missing the tickler springs, which are an easy fix from Abingdon for about .75 each. It's much better if the ticklers do not ride directly on the floats, which the springs prevent.

Tom
t lange

I am with Tom, if the tickler pins are riding on the top of the floats, they are missing the springs. The springs need to be replaced or the pins will eventually rub a hole in the floats and then the floats will flood and never come up. Cheers - Dave
David DuBois

Hi Steve. I have seen numerous tickler pins wear at the shoulder below the head. Also the spring wears so the top is thin to non existant. The shoulder in the float bowl cover wears to a taper which causes the pin to get stuck down and hold the float down allowing the valve to remain open and flood gas all over.

Butch
VMG
R Taras

Steve,

There are a couple of safety matters to consider here, too. The tickler pins are generally considered to be a poor engineering design. Gas can leak from around these pins and land on the hot exhaust system below, risking an engine fire. I wanted the fuel bowl lid to appear original, so cut the "bottom" off the tickler pin and sunk the top of the pin in an epoxy putty that otherwise filled the hole in the lid. There is no need for the springs if the pins are immobilized and the opening sealed as I did.

Make sure you have the correct washer on the banjo fitting on the lid. This is a scalloped washer, which allows excess fuel to flow out the overflow pipes. Also, check the routing of the pipes to make sure they open on the forward side of the engine bearer plate--this also to minimize the chance of an engine fire.

There is much information in the archives on these topics. Have a look and keep asking questions.

Larry
Larry Shoer

Yes, the pins should be held up by the springs. I had similar problem- any time the car sat for a week or so, the front carb would overflow. It was indeed a bad Grose jet. Some of the recent replacement tickler pins have a nice seal with a tiny e clip at the bottom, which should pretty well seal the opening. I epoxyed mine shut however. George
George Butz

SC, I had the identical problem; at some point someone had lost the springs to the tickler pins (and they were also mismatched, one was the OEM and the other was the replacement.

New ones solved the problem.
Geoff Baker

Many people remove the tickler pins and fill in the holes. Besides being a source of air pollution, they are a fire hazard. I know people whose cars burned up because of them. If you get a spark, there is a good source of fuel vapor there with the exhaust right under the carbs.

I used that grey putty that you can drill afterward, whose name escapes me today. Later versions of the carb had a solid topped float chamber. The color matches the chamber when it dries. You can also buy the later style top, but it was $70 last I checked.

If you do this, I found out the hard way, you have to have the proper scalloped venting washer at the overflow banjo fitting or there will be nowhere for the displaced air to go in the float chamber. This is a salient feature of this carb.

Larry
L Ayres

I just took at quick peek and guess what??? No springs at all. Looks like I will get some new ones on order.

Thanks,
Steve
SC Christian

I just replaced the tickler pins and the jets. So far....so good.... Thanks again for all the help.
SC Christian

FYI, jets wear very little, assuming the needles are centered and not rubbing.

Tom
t lange

This thread was discussed between 18/05/2010 and 25/05/2010

MG TD TF 1500 index

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