any one have any clues as to why my new v+h longshots backfire under deceleration
Yeah, too much air... either you have a gasket leak OR (like me) you need a EFI add-on to compensate. I had to add a Cobra FI2000 to mine to get rid of the decel backfiring (after I triple checked that there were no air leaks around the exhaust gaskets). There are several boxes you can choose from ... the Cobra was the easiest and did the trick with no tweaking. Check the accessories area of the web site.
I just put LongShots on my Classic FI (basically the same engine) and had the dreaded popping also. Mine turned out to be the front pipe had not seated correctly. Loosened and re-adjusted and now all is good (I used the old gaskets also).
I have Straight shots on the Drifter and it doesn't pop at all but does have a "gurgle" on decel.
i have a 1999 drifter 1500...i had the same problem...bought a cobra fi 2000 and i have it on the stock setting that it told me to use....runs perfect now. smooth as silk.
thanks to Sandra
Terry
Glad the part is working great! ;D
Thank-you all ....a new set of fresh exhaust gaskets sorted that problem out. Now she sounds and runs righteous! Happy me... Thanks. ;D
Mine does the same thing but I like it. LOL. Am I harming my engine? Should I get new gaskets? Can I leave it as it is? Thanks in advance.
Depending upon the type of backfiring and cause. If you have leaky gaskets, yes they should be replaced. ... and, personally, when I hear backfiring like that I figure the guy is a novice biker who doesn't know how to tune his bike... personal prejudice! <LOL>
Plus is your smog reeds still on the bike. That was what caused all my backfiring. Plated them off, NO more backfire.
I have those pipes. I marbleized my bike in about 10 minutes and ended the backfiring forever. Thank goodness I had kids with marbles. Wait...I mean kids with REAL marbles. Hehe.
If the backfiring is caused by a "lean condition" created by the installation of the pipes, it can be hard on the engine; it will create higher combustion temperatures which can damage top end components, such as valves and pistons. A richer fuel mixture will eliminate the back firing problem. A good way to check if the bike is running lean is to shut it off and pull the spark plugs to "read" the color; they should be a tan to dark tan color. If they are whitish in color, the bike is running too lean; if dark and/or sooty, it is running rich. I installed a PCIII control module on my bike with Cobra 2 into 1 pipes, and totally eliminated the backfire problem.
Regards and such,
49Reo
Quote from: Meridious on October 06, 2010, 13:01:35 PM
I have those pipes. I marbleized my bike in about 10 minutes and ended the backfiring forever. Thank goodness I had kids with marbles. Wait...I mean kids with REAL marbles. Hehe.
Marble trick did it for me too. Cheap, and effective!
Marble trick has to do with blocking some epa smog stuff with marbles. IMHO the best way is to remove the stuff entirely and use coasters... no marbles needed.
http://www.vulcandrifterriders.com/coasters.ihtml
http://www.smog-marbling.html
http://www.VulcanDrifterRiders.com/reedvalveremoval.html
the link:
http://www.smog-marbling.html
does not show up
can someone re-post it please
~thanks
Just for the archive 8)
The correct URL's are:
http://www.vulcandrifterriders.com/coasters.html
http://www.vulcandrifterriders.com/smog-marbling.html
http://www.vulcandrifterriders.com/reedvalveremoval.html
Whenever you remove or replace exhausts you should fit new crush washers..when you buy them they look like hollow hoops but when you fit them they compress to fill any gaps..they are a use once then discard.
John.