How do you replace diaphragm on Mikuni BS29 Carb

A model number is useful or even the 'friendly' name 'Fat Boy' 'Sportster', 'Street Glide' etc.

Videos in the link plus articles.

https://www.google.com/search?q=1995+Harley+Davidson+adjust+Mikuni+52mm+carb

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Which check valve are u referring to? On the metering plate under the main diaphragm or the fuel pump side? The metering plate valve is held in with a plate and single screw the other side is held in with rubber grommets.

Don't know which model of Mikuni carb you have, but here are some diagrams:

http://images.search.yahoo.com/search/images;_ylt=A0oG7md0EsRSkW8A9HdXNyoA;_ylu=X3oDMTB0YnMwNmI4BHNlYwNzYwRjb2xvA2FjMgR2dGlkA1ZJUDM0MV8x?_adv_prop=image&fr=yfp-t-745&va=mikuni+carb+diagram

See if you can find one that matches yours.

Stens is an aftermarket company. might be able to get an aftermarket carb or kit there.

Fuel starvation - 'lean fuel' condition
Basic things to check:
1) spark plug
2) spark arrestor in muffler
3) fuel lines and tank filter
4) turn adjustment needles out (counterclockwise) 1/4 to 1/2 turn
Chain Saws:
5) check impulse tube and intake boot for cracks or leaks
*if all of the above are OK and/or do not improve performance then:
Remove Carburetor
6) replace gaskets/diaphragms
a) use a spray carb cleaner to clean jets, holes, and body of carb
b) fuel pump diaphragm goes against the carb body,
then the gasket towards the outside
c) metering gasket goes against the carb body,
and the diaphragm goes towards the outside

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

hi mate im prety sure these bikes have injectors rather than a carb