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MG TD TF 1500 - Crack in the carb piston chamber

A huge step back in the engine rebuild. I was trying to tune the carbs today and suddenly I noticed a large crack in the lefthand piston chamber. Naturally, the piston now drops much faster than the one on the right...
The cost of a new set of carbs is totally prohibitive on my current budget. Is repair an option? If so, can someone point me to a thread covering this? I could find nothing relevant under "carb crack"...
Very disappointed. I won't be able to get the engine running smoothly without fixing this somehow....
Geoffrey M Baker

Its a horrible bodge but I suspect that if you wrap some insulating tape around it tightly, it won't leak. Then look for a S/H replacement.
Dave H
Dave Hill

Here's a photo

Geoffrey M Baker


Contact me at my email address-- I've got one I saved as a spare.
Richard Cameron

Abingdon Spares lists in stock also.
George Butz

Abingdon Spares lists a single H2 chamber with piston. What about matching? Both pistons have to drop at the same speed, how can you "match" a new (or used one)?
Geoffrey M Baker

Just out of curiosity -

Can you adjust the drop of the new chamber and old piston so that it will match the drop of the other chamber and piston?

Is it really important?

John Twist "drop" video:
http://www.youtube.com/watch?v=IfU47Oqq9wA

Thanks,

Lonnie
TF7211
LM Cook

My recollection is that each piston and piston chamber are machined as a matched set (piston from one chamber won't work in another chamber) so that the drop rate should be close to the same for any matched set. Others with more expertise can confirm or refute this. Jud
J. K. Chapin

I have also added a bit of solder, or drilled out pistons, as necessary, so they were closer to the same drop time. It seemed to work just fine.


Tom Lange
MGT Repair
t lange

John Twist gets it absolutely right - over the years many of the pistons and chambers have got mixed and mismatched. Of course its a desirable to gt them matched, but its not a disaster if they aren't as the engine will still run pretty well.
Dave H
Dave Hill

OK, sorry folks!
The crack that gave me a heart attack turns out to be a nasty gouge on the face of the cylinder. It is in fact not cracked at all! The internals all look good, so I apologize for wasting everyone's time.
What a huge relief for me though!

Guess I can get back to tuning the carbs now...

Thanks for all the suggestions and input.
Geoffrey M Baker

I should add that when I took them apart, there was some serious gumming on one of them, so once that was cleaned, the drop rate of the pistons is back to more or less the same...
Geoffrey M Baker

I was asking myself already what could have caused a crack in that sturdy housing.

Good luck with the tuning.
Willem van der Veer

As a side note..the chambers can be distorted by over tightening of the attach screws. The action of tightening the screws can also change the drop rate of the Pistons to the point they can bind up and not drop through their full range. Regards, tom
tm peterson

This thread was discussed between 20/01/2016 and 21/01/2016

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