Wilsons Sandbox

Bryan Loehr wrote: [...]

> I've modified the airbox with holes > drilled along the top, therefore, a HUGE amount of air was slamming into > the carb, especially with all the honking on I have to do to try to keep up > with the guys I ride with. It's my theory that the high air volume > overstressed the diaphragm. Does that sound right?

Not to me. If you had a huge amount of air slamming into the carby, or at least more huge than usual, then you should have been making hugely more power. I've changed one diaphragm so far and the replacement is still working ok. Some fail and some don't although I suspect that more than a couple of backfires through the carby won't do the longevity any good.

> The new diaphragm assembly I have on order cost $116. (Not a typo--one > hundred sixteen dollars!) A pure case of "Sh*t happens."

Yeah, not cheap in any currency. Mister_T

> A week or so ago I posted a request for advice regarding a sudden power > loss on my 99 KLR. With about 800 miles on a Dynojet/Supertrapp/K&N > upgrade, it all of a sudden wouldn't rev past 5K. I discovered the cause > to be a small tear in the carb diaphragm.

Bryan, I'm far from a carb expert...but I would suspect some other cause for the tear. BTW, while I tend to exactly as you are with replacing the diaphragm we have had listers repair the diaphragm with some sort of vinyl repair product (again, probably in the archives) and it has held up perfectly. You might try repairing it and keeping the new diaphragm on hand in case of a failure. Regards, Kurt

At 8:40 PM -0700 6/17/2000, Bryan Loehr wrote:

> It's my theory that the high air volume >overstressed the diaphragm. Does that sound right?

If the tear was near the edge, it's more likely that the diaphragm was damaged upon reassembly after installing the DynaJet needle if the diaphragm didn't seat properly (twisted or creased) in the groove. Mark B2 A2

> Listers, > > A week or so ago I posted a request for advice regarding a sudden power > loss on my 99 KLR. With about 800 miles on a Dynojet/Supertrapp/K&N > upgrade, it all of a sudden wouldn't rev past 5K. I discovered the cause > to be a small tear in the carb diaphragm.

............................>snip > overstressed the diaphragm. Does that sound right? >