carb diaphram

do i have to replace this? or can it be left alone
there's no hole and i can't see light through it

 

How does the bike run?

 

As finicky as these motors are in regard to the carbs, I would. I guess the problem is balance between the 4 carbs. I found a site for an alternative source of diaphragms.. http://jbmindustries.com/HITACHI.html
They price them at $19.50 each. I haven't used them myself, but is would be a less expensive fix IMHO.

 

Not sure why it's like that but I would say as long as there isn't any damage to the rubber diaphragm itself and the seal between the piston and the diaphragm is tight then you should be fine. Although if you do replace it, I would definitely recommend the a fore mentioned company JBM Industries. They make an excellent replacement at a very reasonable price.

 

My 650 had one like that. From the discoloration at the break I'd guess it had quite happily spent many years like that.

I did repair mine, but thinking back on it it probably wasn't a good idea. The heat and flame involved could damage the diaphragm.......

I'd use it until it was a problem.

 

The ring is suppose to be solid, they shrink and crack over time. I have some on both my XS and XJ11 that are cracked. Run them like that, I do.

 

I wouldn't be surprised that more than 50% of all the XJs still on the road have at least one of these rings cracked.

I suspect it would accelerate the deterioration of the diaphragm where it makes contact with the broken ends of the ring, but how long will it take to punch holes through it?

 

interesting, in the last 4 or 5 months I have been inside 4 racks of carbs from 1982 and 1983. none of them have that issue. maybe I am just lucky.

CN

 

I asked the same question years ago a few of mine are cracked as well, runs fine. Don't worry about it, unless it's ripped.

I also find it hard to believe that the plastic ring *shrunk* THAT much in 30 years. I wonder if some of them are like that, from new.