Bonneville America Forums Forums Technical Forums Exhaust From Sewing Machine to Popcorn Popper w/TOR's

Installed a set of TOR pipes on my SM this AM. Love the sound...just what I wanted. Lot's of popping on decel though. Orville Redenbacher would approve but well, popcorn is best served with butter-flavor topping at the movies.

What needs to be done to the carbs? Is this something a mechanic has to do or is it an easy fix I can do at home? My skill level is, oh...whats less than basic?

Does anybody know of a step-by-step dummies guide anywhere on the net I can follow to fix this? Thanks.

Have you removed the AI and backed the idle mix screws out? I don't know that this will stop the popping, but it would seem those who've done it don't have the problem. Basic skill level will work.
If you need it, do a search on idle mix as it's been described many times. Same with the AI removal.
Although... I don't know if anyone's done it with the new engine.

With the Triumph TORs, I'd go with 125 to 130 mains, and turn the mix screws out to 3 - 3.5 turns. Try that and see what happens. You'll start educating yourself on these CV carbs (better than the old Amals).
Just Ride Safe,
Dennis

Roland -

I had this problem after installing new exhaust and rejetting. Here's my setup:

-at sea level basically
-have cut as much of the airbox out as possible
-snorkles removed
-unifilter
(the four points above tell me I've got a LOT of air coming through the carbs, relatively)
-SS long canons
-TBS needles
-130 or 132 mains (can't remember)
-48 pilots

disclaimer!! - there are a lot of things about carbs and fluid dynamics and engines in general that i have not a clue about, so I would try others' suggestions before mine! also, the amount of air that you have coming through the system will obviously be a big part of the equation - if you haven't modified your airbox then this probably isn't for you. all that being said...

after a lot of jacking around, i found that the popping behavior followed the description at the end of the following article, to the tee:

Decel popping advice

Popping decreased as I gradually turned the mixture screws out to 4 turns w/ the 45 pilots in - switched to the 48's and it is better than w/ the 45's but still not perfect. The way I confirmed was to pull the choke, while riding, to see if I got the popping then - it completely went away w/ choke full out. That tells me that when the choke is in there's not enough fuel getting through the system on decel, a throttle position which supposedly points to the slow (pilot) jets. I'm going to do an experiment going to 50 or even 52's and will let you know what I find. hoping that I can get to a point to where i'm right around 3 turns w/ no popping and a slightly lower idle than i'm currently using.

one hint re rejetting - get some hex head thumbscrews to replace the bowl screws on the carbs - you do that and it's a snap to tweak your pilots and mains w/o pulling the carbs (otherwise you run the risk of stripping the stock screws). the whole operation took me about 20 minutes last time and that included draining the bowls, dealing w/ a hot engine, etc.

I have the short TORs and so far have not been able to eliminate the popping completely. Removed the AI and turned the screws out 3 1/2 turns. This lessened the popping by about half. I will note however that nearly all the popping is coming from the left cylinder and I can tell by the headers and spark plugs that it's running leaner than the right one. I bought 130 mains but have not had time to install them. No air cleaner mods. Seems like if it's running lean the last thing you need is MORE air. Good luck, the TORs are notorious for this problem.