Carb diaphragm not sitting properly

[Wasp]

i feel a big uh oh oh crap comming on here...

pulled the carbs apart today and cleaned them - during reassembly on the diaphragm side when i was putting the covers back on numbers 3 and 4 went on perfectly fine.

looking at my handy work i noticed the diaphragm for carb #1 was sticking out and ovbiously not sitting properly so i pulled that off and after a bit of fiddling got it in nicely (i guess the rubber is just old and cant hold its shape)

but number 2 carb well - i played around with it for possibly up to 20 minutes trying to get it to sit, eventually got it in but i think its folded around the edge and hence the problem (i'd say its definately folded cos i thought it looked like it but i had it shut so yea.... and it doesnt accelerate right and exhaust sound is different (for anyone who knows my bike - its balls dropped :rofl:))

oh right the question, anyone know any tricks to getting worn out diaphragms to fit?

found on a japanese site that i use for a manual (someones personal page) they are 2,000 yen to replace each - not sure how much that is.....

[limbimtimwim]

oh right the question, anyone know any tricks to getting worn out diaphragms to fit?Yes, they can be a bitch.

Put some petrol on them, they will soften up.

For someone who disassembles and re-assembles laptops, I'd think carbs would be like working on steam engine in regards to the size of the bits and pieces.

Don't ride the bike! If they are not in right, they could be pinched and their movement could tear them.

Also, are you 100% sure the carbs are seated correctly in their boots? And they are done up? Could a boot have got torn? Air leaks will make the bike behave very strangely. Shouldn't be too hard on an inline four to get them in though..?

[Wasp]

what the hell is a boot?! is it the rubber join between engine-carb and carb-airbox?

atleast with the laptops everything fits and there are plenty of spares....

is petrol still a good idea? i reckon they are too soft - need a way to make it tighter

got all day to do it tommorow so yeee haaa :P

[Motu]

No.Clean them well with soapy water or something and leave to air dry for 24 hrs or more.Last week I had a float bowl O ring that wouldn't fit back in the groove....next morning it fitted right in like new.

[xwhatsit]

found on a japanese site that i use for a manual (someones personal page) they are 2,000 yen to replace each - not sure how much that is.....

Easy way to do Japanese currency is just chop off the last two digits -- so about $20. Current exchange rate... *types*... means it comes to $24. Not exactly a house re-mortgage. EDIT: That said, there are four... I love singles :D

[dickytoo]

silicone grease or ahem, cough vaseline works well. just smear some on the diaphragm and it will hold it in place long enough for you to replace the carb top.

[Wasp]

lol

cheers guys, forgot to post that i had it due to the trackday

just soaked it in petrol for awhile and then managed to get it sitting properly enough to get the cover on

thanks again :yes:

[Motu]

just soaked it in petrol for awhile

:gob: Good luck.

[dickytoo]

actually motu, i was given the same advice by a couple of bike mechanics when i was restoring a basketcase GPz550. The diaphragms had dried out, shrunk and hardened and i was told to soak them in petrol for awhile and they would soften up and be usable again. same with the boots.

It actually worked!

[Wasp]

:gob: Good luck.
whys that motu? you reckon the petrol will eat them or something?

seems fine so far.... mabye i should sell it....

[Ixion]

It depends what they've done. Rubbery things (carb boots, diaphragms, oil seals ) do one of two things.

They go hard and inflexible; or they stretch distort and go all woofly.

If they're hard, soak them in petroil (note the 'i') and some UCL. If they've stretched clean and soak in soapy detergenty water and leave to dry.

The OP sounded like stretched, not hard. So petrol may make them worse.

[Motu]

whys that motu? you reckon the petrol will eat them or something?


Too right it will.If your diaphrams had expanded I don't think petrol would shrink them,more likely soften and expand them.Most carburettor components are fuel safe....but not really diaphrams as they don't come into contact with the fuel.As a general rule,don't put any rubber type material,no matter what it's called,anywhere near fuels.

[Wasp]

ooohh....

i did spray some carb cleaner up in there, she'll be right :innocent:

im not even sure the petrol itself helped - it fitted anyway