Caps For Permanent Sync Adapters

[1948man]

When I ordered my Morgan Carbtune, I got some brass sync adapters to mount permanently. I capped them with these...

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Vacuum-Cap-Assortment-with-Rubber-Vacuum-Caps-from-5-32%22-to-3-8%22-Dorman---OE-Solutions_9110159-P_N4016_A%7CGRP2037_____

The caps have cracked in the first 10 days. I noticed this when I was preparing to do another sync because my bike started running not quite like it was a couple of weeks ago. I guess the caps can't take the heat? Does anyone have an idea what rubber product would stand up better in this environment?

[Larry D]

Why not just put the small allen bolts back in ? It's not that difficult to remove them and install the brass adapters when you want to do a sync.......

[1948man]

I have the temporary brass adapters and a permanent set. I got the permanent ones because it's pretty hard to fiddle with the allen bolts, at least for me. It' not so much taking them out but getting numbers 2 and 3 back in is a pain. They have to be lined up perfectly to get the threads started and you have to have an allen wrench just the right length and some way to keep the bolt and little washer from falling off and getting lost. (I use chewing gum). I hoped the permanent brass adapters would make it less of a headache. I'm wondering if I just got a bad batch of rubber vacuum caps

[bwringer]

Hi-temp rubber caps:

http://www.mcmaster.com/#rubber-caps/=bh77x6

About ten bucks for 100...


I'd probably just push on some fuel line and cap it with a bolt if it's a nice day to go riding.

[1948man]

Thank you very much Brian. You've provided the perfect answer.

[1948man]

The heat-resistant ones will withstand 600 Degrees F for 10 minutes while the chemical resistant ones will withstand 475 degrees for 10 minutes. Since I occasionally get a little gas (from a backfire I guess) in those caps, I got the chemical resistant ones. I figure if they will withstand 475 degrees for 10 minutes, they ought to be okay at 200 degrees all day. How hot do you suppose those little brass adapters get?

[bwringer]

Good spot -- I think the chemical resistant ones would be the better choice here.

Even though you don't see much liquid gasoline at these ports, they do spend every running moment exposed to gasoline vapor, which will damage sensitive materials even faster.

I don't think the brass adapters would get near the boiling point unless you have something else seriously wrong, like the engine's on fire.

[Matchless]

It' not so much taking them out but getting numbers 2 and 3 back in is a pain.

Use a length of rubber fuel hose that fits around the cap head and your problems are solved!