Starter plunger dust cap

[bosco659]

While rebuilding my new to me BS38’s, I noticed the starter plunger (choke) dust caps were rock hard and cracked. XS650Direct had replacements so why not. I chipped off the old one and cleaned top of the retaining nut. Went to assemble the new cap and it was way too large to snap onto the retaining nut groove. The groove measured close to 7mm and the new cap close to 9mm at the widest point. Is there a source for these caps or something that will fit relatively well? Spring removed for pics.

Desperate to find a solution, I dug through my misc carb parts and took apart a spare “Chinese” choke assembly for my PWK32’s. I tried to fit the dust boot to the retaining nut and I think that if I’m forced to, I might be able to make it work. Looks hood in the pics but the ‘“new” cap doesn’t fit really tightly either, but better than the 9mm one. Hopefully there’s a better solution out there. Any help is appreciated. Thx!

 

[DogBunny]

I believe these dust caps are a non-critical item. Yes, you want them to be there, but they do not have to actually seal. If they are rock-hard, I just let them be, and do not try to remove or disturb them.
I do not know if there is a source for these dust caps. The one you made will probably work. Again, it would be nice if it sealed, but it will still work if it doesn't. The only other thing I know to do is to buy used, in which case you probably want to buy the plunger with cap attached, and not disturb it. I have them, but I'm in the U.S.

 

[bosco659]

I believe these dust caps are a non-critical item. Yes, you want them to be there, but they do not have to actually seal. If they are rock-hard, I just let them be, and do not try to remove or disturb them.
I do not know if there is a source for these dust caps. The one you made will probably work. Again, it would be nice if it sealed, but it will still work if it doesn't. The only other thing I know to do is to buy used, in which case you probably want to buy the plunger with cap attached, and not disturb it. I have them, but I'm in the U.S.

Thanks DB. I’ll take your advice and leave the other cap on. The new one I retrofitted will work with a really small zip tie around it’s base. The aftermarket replacement ones that are available have fitment issues.