Rumbled carb diaphragm - SV650.org

31-01-12, 05:25 PM

Today I tested the a/f monitor on the bike and decided I had to raise the needle.
Took caps off and noticed the front diaphragm is rumpled(ruffles shape) at one spot.
It's been only 2 months when I tore down the carbs,adjusted them and replaced what had to be replaced.Diaphragms looked great then.
I wonder why.
Here's what i thought:
a)Τheres' absolutely no way the elevated contour of the membrane be perfectly aligned and entering the pit around the perimetre of the carb when you bolt the cap at the full length of the pit.
b)Before balancing them the carbs were wayyyyy off.I did about 150km this way.

Any ideas?

Sid Squid · 31-01-12, 11:11 PM

Are you sure it didn't seal before? You'd notice it soon enough if it didn't - it wouldn't run right.

The diaphragms are affected by fuel and are often badly swollen, when reassembling them you often have to carefully pick your moment as they dry, (or if too dry, as they enlarge again when you dampen them with fuel to make them swell), in order to make everything fit.

01-02-12, 01:07 PM

Bike ran great even witht he rumpled membrane and it sealed fine.
I'll replace with an old one and put the rumbled one on an ld carb to see if it gets back to shape.

31-01-12, 05:25 PM	#1
TOLAROS Guest Posts: n/a	Rumbled carb diaphragm Today I tested the a/f monitor on the bike and decided I had to raise the needle. Took caps off and noticed the front diaphragm is rumpled(ruffles shape) at one spot. It's been only 2 months when I tore down the carbs,adjusted them and replaced what had to be replaced.Diaphragms looked great then. I wonder why. Here's what i thought: a)Τheres' absolutely no way the elevated contour of the membrane be perfectly aligned and entering the pit around the perimetre of the carb when you bolt the cap at the full length of the pit. b)Before balancing them the carbs were wayyyyy off.I did about 150km this way. Any ideas?

31-01-12, 11:11 PM	#2
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rumbled carb diaphragm Are you sure it didn't seal before? You'd notice it soon enough if it didn't - it wouldn't run right. The diaphragms are affected by fuel and are often badly swollen, when reassembling them you often have to carefully pick your moment as they dry, (or if too dry, as they enlarge again when you dampen them with fuel to make them swell), in order to make everything fit. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

01-02-12, 01:07 PM	#3
TOLAROS Guest Posts: n/a	Re: Rumbled carb diaphragm Bike ran great even witht he rumpled membrane and it sealed fine. I'll replace with an old one and put the rumbled one on an ld carb to see if it gets back to shape.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
99-02 DIAPHRAGM COVER CAP wanted	SvJoy	Stuff Wanted	2	30-04-11 11:55 AM
What's the stock size of the hole in the carb diaphragm?	TOLAROS	SV Talk, Tuning & Tweaking	1	25-05-10 07:21 PM
Wanted: Clocks for carb model naked + headlight and carb.	Gazdaman	Stuff Wanted	2	17-03-10 03:50 PM
Brake Fluid Resevoir Diaphragm and level check	branny	SV Talk, Tuning & Tweaking	11	27-01-09 04:11 PM
scoobs rumbled ??	leemole	Idle Banter	3	24-10-07 08:07 AM