TR2/3/3A TR3B SU carbs

[psutr3]

Bought new H6 SU carbs for TR3B. After putting oil in chamber I noticed that the piston in one carb required much more pressure to raise and fell at a slower rate. When I reversed the dampers on the carbs the the rise-fall of the pistons reversed. I’m not the greatest mechanic but I understand that the pistons should require about the same pressure to rise and fall at about the same rate. First, is that correct? Second, can I correct it or should I contact Moss for another pair of dampers? I tried dampers from an old set of carbs and they actually seemed to give a more even rise-fall. Whatever help I can get is appreciated.
Gary

 

[DavidApp]

Sounds like a badly made part. One of the pistons is not right. Moss may supply new dampers. The New SUs are not a cheap item.

David

 

[CJD]

Before sending them back, perhaps remove the pistons and clean the pistons and domes with carb cleaner. See if that evens them out. I'm thinking there could be some preservative on them from the factory. If that doesn't help, then +1 on returning them.

 

[sp53]

How about when the engine is warm and the brass filler rods are removed, do they fall any better? Anyways heck yes 2K for the carbs--- be happy—send them back.

steve

 

[charleyf]

There is a large spring underneath the dome of each carb. Could one be missing? There are several things that determine the fall of the pistons besides the dampers. But in truth, if just cleaning them does not correct the situation you should send them back. If you just paid what I see they are selling for then you should get good products. If it were me I would not give them the option of only replacing the dampers. Replace the whole set.
Charley

 

[poolboy]

If the problem followed the damper...it's the damper...Sometimes the damper rod can be a tiny bit bent, just enough where there's some friction from rubbing the wall of the damper well..

 

[sp53]

If the needle is not centered they will not fall correctly either. They could need a good adjusting. I doubt if they can be sold adjusted. Mess around with your old set to understand the basics.
steve

 

[poolboy]

That's true, but didn't the problem follow the damper exchange ?

 

[bobhustead]

I recall reading from some seemingly authoritative source that the pistons and covers are sets and it is not always possible to swap a piston from one cover to another. Could you have made such a mix-up in handling the parts during assembly or installation? On rereading your first post, the swap of dampers reversing the problem may be inconsistent with this possibility
Bob

 

[bobhustead]

After a bit more thought, has the result of your damper swap not told us that the problem is one of the dampers, as Ken says?
Bob

 

[psutr3]

Contacted Moss and parts guy was very pleasant and helpful in explaining their policy and my options but could not do much. It was referred to tech people who could take as much as two weeks to call me. It does seem to me that it is the damper but the parts guy can’t do anything until tech people make a decision. I could buy two new dampers but that is another $90 plus shipping and I am not inclined to do that. I could buy another set of carbs and Moss would refund the cost of one set if tech people decide first set had a defect but if they don’t….. I’m just going to wait for tech people.
Gary