SuzukiSavage.com - Fixed muffler leak, now running rough

SoE

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Fixed muffler leak, now running rough
07/08/11 at 05:42:34

I've had a HD muffler on for weeks for now, no problem except a little air leak where it attaches.

I put a cone filter last week and have ridden a bit with no big differences except a little more pop when I let off the throttle in first.

Last night I decided to tackle the air leak and really sealed the muffler up way better than it was. It's still not 100%, but there's barely any air escaping between the muffler and exhaust now.

It gave me a little more trouble than usual starting this morning and I actually had to use the choke to turn it over and keep it idling until it warmed up a little.

Rode a few miles, noticed rain coming, decided to drive the car. On the way back it really started to act up, popping a lot when I let off the throttle and hesitating in low gear. I stopped just before home and it was acting like it wanted to die unless I really gave it some throttle.

Need to troubleshoot it tonight, any ideas? Is it airflow/back pressure issue causing this? Should I go back to the stock air filter?

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spacepirates

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Re: Fixed muffler leak, now running rough
Reply #1 - 07/08/11 at 07:00:39

let the bike idle (with choke off) for a few minutes (put a fan on it so it doesn't overheat). pull the plug and see what it tells you. you want a nice tan/brown color on it. darker means too rich/too much fuel. lighter means lean/not enough fuel.

sealing up the exhaust could have uncovered a problem with how your bike is jetted.

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EJID Serious Thumper Offline Work to ride and ride to work. Posts: 1536 Pocatello, ID Gender:	Re: Fixed muffler leak, now running rough Reply #2 - 07/08/11 at 07:23:35 I agree with space, but my bike tends to act the same way when I'm just about out of gas. It sputters, lugs, hesitates, whatever you want to call it along with additional popping. When I switch to RES it clears up and I know I need gas. Just my $.02
Back to top	05 S40 15" Memphis Slim, FXDWG Bars, Moved Rear Signals, Saddlebags, Fork Bag, Mini-Tach, Raptor, Cone Filter, Fishtail Muffler, Mix Screw Out 2.5 Turns, 4" Fwd Controls, 147.5 Main/55 Pilot @ 4500 IP Logged

SoE

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Re: Fixed muffler leak, now running rough
Reply #3 - 07/08/11 at 07:32:09

Yes, that's exactly how it acted. I just put some in, but maybe I've ridden more than I realized. I should check that first

But assuming its got fuel, that says its maybe too lean in the lower range?

Should I try adjusting the mixture screw? I've read a lot of the posts on this stuff, but I haven't messed with the carb yet & it's easy to get lost in all the responses when researching.

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EJID

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Re: Fixed muffler leak, now running rough
Reply #4 - 07/08/11 at 07:38:08

I used to think that diving into the carb to rejet was more involved than I wanted to get. When I went to do it a few weeks ago, it was so simple that I had to ask myself why didn't I just do this sooner. It is really easy to swap the main and pilot without having to take the carb off the bike (just be REALLY sure you have a screwdriver that fits well in the bowl screws) also, make sure you are turning them the correct direction.

Next time I'm diving into the top to get at that white spacer Huh

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05 S40 15" Memphis Slim, FXDWG Bars, Moved Rear Signals, Saddlebags, Fork Bag, Mini-Tach, Raptor, Cone Filter, Fishtail Muffler, Mix Screw Out 2.5 Turns, 4" Fwd Controls, 147.5 Main/55 Pilot @ 4500

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jdeluca

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Re: Fixed muffler leak, now running rough
Reply #5 - 07/08/11 at 07:40:22

I'm far from an expert on much of anything, but I wonder if your exhaust leak was leaning your mixture out a little, and now that you've corrected that (for the most part anyways) now you might be on the rich side of the spectrum. Add that to a more humid (just before the rain came) part of the day and there's even less oxygen getting in their (higher humidity = less dense air) which would make you richer still. You can try turning your mixture screw clockwise, which would lean you out a little bit, but if that bottoms out with no change then you'll need to go down a step in your pilot jet. It's impossible to jet with an air leak somewhere. Just my $.02, to add to EJID's. Keep it up, you might have a whole $1 soon! Grin

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SoE

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Re: Fixed muffler leak, now running rough
Reply #6 - 07/08/11 at 11:24:19

EJID wrote on 07/08/11 at 07:23:35:

I agree with space, but my bike tends to act the same way when I'm just about out of gas. It sputters, lugs, hesitates, whatever you want to call it along with additional popping. When I switch to RES it clears up and I know I need gas. Just my $.02

Dude, I think u called it. The tank was lower than I expected. Switched to res and rode it with no trouble. Been riding more than I realized.

For the record, is the air/fuel mixture screw the little brass one on the top right of the carb next to the hose going to the motor?

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CalisOsin

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Re: Fixed muffler leak, now running rough
Reply #7 - 07/08/11 at 11:36:50

SoE wrote on 07/08/11 at 11:24:19:

EJID wrote on 07/08/11 at 07:23:35:

I agree with space, but my bike tends to act the same way when I'm just about out of gas. It sputters, lugs, hesitates, whatever you want to call it along with additional popping. When I switch to RES it clears up and I know I need gas. Just my $.02

Dude, I think u called it. The tank was lower than I expected. Switched to res and rode it with no trouble. Been riding more than I realized.

For the record, is the air/fuel mixture screw the little brass one on the top right of the carb next to the hose going to the motor?

No worries, it happens to everyone at least once.

Take a look here to see what air fuel mixture screw

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1221818822/0#0

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spacepirates

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Re: Fixed muffler leak, now running rough
Reply #8 - 07/08/11 at 11:37:23

SoE wrote on 07/08/11 at 11:24:19:

EJID wrote on 07/08/11 at 07:23:35:

I agree with space, but my bike tends to act the same way when I'm just about out of gas. It sputters, lugs, hesitates, whatever you want to call it along with additional popping. When I switch to RES it clears up and I know I need gas. Just my $.02

Dude, I think u called it. The tank was lower than I expected. Switched to res and rode it with no trouble. Been riding more than I realized.

For the record, is the air/fuel mixture screw the little brass one on the top right of the carb next to the hose going to the motor?

There I go, getting all into a deeper issue when the simple ones haven't been ruled out...

This post has what information you need on the brass mixture plug:
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1221818822/0#0

While your immediate problem (the hesitation/surging) has been fixed with fueling up, given that you have done some mods to the bike (HD muffler, K&N filter), it wouldn't be a bad idea to check the spark plug to see how you are running anyways. not too much work to get at it.

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SoE Full Member Offline Rollin' the dice on fire... Posts: 199 East TN Gender:	Re: Fixed muffler leak, now running rough Reply #9 - 07/08/11 at 13:00:41 I agree. I'd like to minimize some of the extra popping I get now when letting off the throttle in lower gears.
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SoE Full Member Offline Rollin' the dice on fire... Posts: 199 East TN Gender:	Re: Fixed muffler leak, now running rough Reply #10 - 07/08/11 at 13:23:42 Someone did me a favor and removed the brass plug at some point. Makes things a bit easier....
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Oldfeller--FSO

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Re: Fixed muffler leak, now running rough
Reply #11 - 07/09/11 at 01:37:12

Problem you describe with low gas level in the tank causing very poor running seems to go away with installation of a Raptor petcock -- is it the onset of the fuel starvation vac carb symptom/effects that will eventually drive you to make the switch over to the Raptor petcock.

All the tuning and rejetting that folks are telling you to do are fine, but I'd switch the petcock first then have to go through only what is needed (some of what you see now are phantom butterflies thrown up by your early level vac petcock issues).

Raptor petcock first, then sort out what's real .... saves effort and unnecessary rejettings.

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