General Carb 28 throttle blade/plate sticking when fully open....

[jtrashy]

My 26 throttle plate sticks thru most of the movement, my 28 only sticks at full throttle and the spring doesn't reset it. I have to manually return it on the carb.
Video of carb throttle plate sticking .....



It didn't stick before so I assume it shouldn't. How do I fix it?
Thanks

 

[bugsymike]

Definitely not normal and potentially dangerous on any make of vehicle.
Can be caused by a bent spindle if no external linkage faulty.
It is possible to buy a spindle and butterfly kit with screws etc. Even different spindle sizes where worn. Forum Members will be able to advise where.
It may have been caused by someone stripping the carb and not positioning the butterfly on the spindle correctly or pressing too hard when tightening the screws causing distortion.
Generally from the factory the screws are tightened and peined over slightly to prevent them undoing, this means if you attempt to undo them the threads damage and cause problems, so best not disturbed unless being replaced with new, in which case careful alignment and checking operation before final tighten and light pein to prevent undoing without damage.
Note they are usually shaped to make a good fitting seal when shut by a slight bevel to the edge that closes , so make sure correct fitting.

 

[smart51]

Third time lucky with my replacement spindle, and yes, I stripped the threads taking the screws out of the old one. I only wanted to clean it.

The first replacement came from Ricambi Fiat 500 Spare Parts. It was 0.5mm oversize. They took it back and refunded my payment saying they only had that size.

The second replacement came from Ricambio Ltd. They listed +0mm +0.25 and +0.5 sizes, so I thought I'd be OK. The one they sent was 0.5mm over size. They answered my first email with a request for photos. They haven't answered subsequent emails. I haven't bought anything from them since.

The last one came from Webcon UK. They were a lot more expensive as genuine parts are, but at least it was the right size.