SuzukiSavage.com - still backfiring

bigvl800rider

Ex Member

still backfiring
01/12/07 at 10:04:37

did the rejet to 155 main and 55 pilot. new plug dpr7ea9-all i can find here. 1/2 white spacer mod done. adjusted the idle screw, air/ fuel screw (drilled the plug) and the dang thing is shooting flames 6-8 inches out of the screaming eagle. only a 20g shotgun sound now. i put the muffler on with flexible pipe as it would not line up. is this bad? seems to have a good seal. ideas? no smell of raw fuel. HELP ME!!!

Back to top

IP Logged

Dynobob Serious Thumper Offline 2003 LS650 (with Supertrapp) Posts: 634 Northern Virginia Gender:	Re: still backfiring Reply #1 - 01/12/07 at 11:44:10 You probably have exhaust leaks. That could make your bike backfire like a 20 guage. Check for intake leaks as well.
Back to top	IP Logged

bigvl800rider Ex Member	Re: still backfiring Reply #2 - 01/12/07 at 11:46:23 pretty much what i was thinking. gonna get wrenching and get a real pipe bent as an adaptor. love the sound now. intake side is good and sealed. exhaust is questionable. thanks for the input.
Back to top	IP Logged

Savage_Rob

Serious Thumper
Alliance Member

Offline

Mechanically
Inclined Amateur

Posts: 6972
Texas (Dallas area)
Gender: male

Re: still backfiring
Reply #3 - 01/12/07 at 11:51:28

Dynobob wrote on 12/31/69 at 16:00:01:

You probably have exhaust leaks. That could make your bike backfire like a 20 guage. Check for intake leaks as well.

I agree completely. If you've already tuned your carb, that's where I'd look next. I had retuned my carb quite a few times before replacing the exhaust gaskets but replacing both gaskets cured my problem. If you haven't tuned the carb, try reading Lancer's Straight & Simple Carb Tuning in the Tech Ref forum.

Back to top

IP Logged

bigvl800rider Ex Member	Re: still backfiring Reply #4 - 01/18/07 at 15:16:28 svage rob, with the k&n and rejet, could i run the stock muffler with any problems? i can drill the muffler if needed.
Back to top	IP Logged

Savage_Rob

Serious Thumper
Alliance Member

Offline

Mechanically
Inclined Amateur

Posts: 6972
Texas (Dallas area)
Gender: male

Re: still backfiring
Reply #5 - 01/18/07 at 18:00:24

bigvl800rider wrote on 12/31/69 at 16:00:01:

svage rob, with the k&n and rejet, could i run the stock muffler with any problems? i can drill the muffler if needed.

With the stock muffler, you don't need to use a K&N but rejetting to something like a 150 and tuning the carb will help. Personally, I wouldn't drill the stock muffler. To free up some more power, I would use a freer-flowing muffler and rejet. The K&N is optional but I believe it makes a difference.

Can anyone who has actually drilled their stock muffler report their results?

Back to top

IP Logged

john1652

Ex Member

Re: still backfiring
Reply #6 - 01/18/07 at 18:10:28

I was just thinking this too if you took the snorkle out or drilled the air box that could certainly lead to lean problems. When I put one of them on my bike it didn't backfire , well yes it did but just a little. and I thought maybe about goin up even to the next jet size. I run 155 that's a pretty open pipe why not try next step up in jetting or if you did airbox mod cover em up. it has to be too lean. john

Back to top

IP Logged

bigvl800rider

Ex Member

Re: still backfiring
Reply #7 - 01/18/07 at 18:15:32

hi john, hows it going? i did the 155 main and 55 pilot. i still havent got to fit the exhaust properly. i got to get time to figure angle of bend. not like im going anywhere as its gonna be snowing here right shortly. anyway, i did not drill the air box, just a k/n drop in. intake is not leaking. header pipe is tight. i still have the flexible exhaust pipe on to the muffler. father in law told me it his on his generator also leaks. guess as soon as i can i will get a pipe fabbed up. thanks for the info.

Back to top

IP Logged

steelwolf Serious Thumper Offline "I'm a cowboy, on a steel horse I ride." Posts: 847 Trinity, NC Gender:	Re: still backfiring Reply #8 - 01/18/07 at 18:16:03 I drilled out the stock can. I kept it on long enough to replace it with the open pipe. It sounded like crap and the performance difference was not noticeable. I also drilled holes in my air box door and that too was a mistake. YMMV The degree of bend for the adapter pipe is 10*.
Back to top	IP Logged

flywest YaBB Newbies Offline The West is Best Frederiksted St. Croix. Posts: 14 St.Croix US Virgin Islands Gender:	Re: still backfiring Reply #9 - 01/20/07 at 02:39:34 Hi Steelwolf, I have yet to do any Mods to my bike, why do you say that drilling your air box door was a mistake? ???.
Back to top	IP Logged

justin_o_guy

Ex Member

Re: still backfiring
Reply #10 - 01/20/07 at 14:47:23

I poked 1 hole inside the muffler.Used a 3/8 bit, had to start it with a dremel type tool with a little metal grinding burr to give the drill bit a place to grab, then held the bit at an angle & drove it sideways till I had a good enough spot to drill on. Pushed & shoved & finally got the hole in it. The sound? Not low, not a rumble. sounded like someone trying to whistle but couldn't, just pulsed hard blowing.The Supertrapp is soo nice.

If I had it to do over I wouldn't mess the stock muffler up.

Back to top

IP Logged

steelwolf

Serious Thumper

Offline

"I'm a cowboy,
on a steel horse I
ride."

Posts: 847
Trinity, NC
Gender: male

Re: still backfiring
Reply #11 - 01/20/07 at 17:07:33

flywest wrote on 12/31/69 at 16:00:01:

Hi Steelwolf, I have yet to do any Mods to my bike, why do you say that drilling your air box door was a mistake? ???.

I was getting WAY too much air for my mix. Some here have done that mod and had no problems with it. I don't think it's a bad mod, it just didn't work out for me with my set up.

Back to top

IP Logged

verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 29042 L.A. California Gender:	Re: still backfiring Reply #12 - 01/20/07 at 17:29:36 If you're running rich, it'd be a good mod. Otherwise it's going to make the backfiring worse. Try the snokel mod first, then remove the door to check it out. 8)
Back to top	Versey's Place Tech Section Index IP Logged