OMG! my exhaust was red! HOT! HELP?

[J_Walker]

I've never seen or heard of this before! But I was turning over my bike and the exhaust pipes coming right off from the engine we're turning red hot! I was "warming up my bike" I got jumpy cause I didn't know what was up and something started smoking so I shut the kill switch and the thing backfired on me! Please guys any help on this? The bike was started cold it was only ran for about 30 secs before everything turned red and started to smoke!

[weedahoe]

that happens when the AFR is too rich. IMO you need to get a wide band AFR like an Innovate LC-1 and dial in your AFR. Too righ or too lean isnt good ether way

[J_Walker]

Can you point me to what your talking about? Possibly a link?

[weedahoe]

http://www.innovatemotorsports.com/products/lc1.php

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=innovate+clamp&_sacat=See-All-Categories

cheaper on ebay though. I use them on all my custom builds and after any engine performance parts like cams have been installed.

They make a clamp to put the O2 sensor in the pipe. The other end plugs into the actual Innovate LC1 module and that connects to your PC or laptop and gives a read out. From there you can start adjusting your mixture screws to get the right AFR at normal driving and WOT

[J_Walker]

So how exactly does this work? like I mean how did I go from not having a problem to having a problem?

[weedahoe]

maybe vibrations from the engine or road made the screws turn. Maybe your exhaust is partially clogged.

[J_Walker]

What screws? On the carb?

[weedahoe]

all carbs have mixture screws that determine how much air and fuel (ratio) the engine gets

[noiseguy]

Ah, before you start bunging in a O2 sensor, why not pull the carbs and see what's going on?

Sounds like a stuck float or a jet's fallen out to me.

[weedahoe]

agreed on the carbs as thats likely where the issue is but one thing i dot see around here is anyone with a wide band actually checking and knowing for sure what their AFR is.


I guess everyone is guessing theirs is right?

[GS500LAWTON]

My CRF-450 MX bike did that because it had bad fuel in it? Is that a possibility?

[ohgood]

some one push his choke to 'off'. 

[bigfatcat]

I've never seen or heard of this before! But I was turning over my bike and the exhaust pipes coming right off from the engine we're turning red hot! I was "warming up my bike" I got jumpy cause I didn't know what was up and something started smoking so I shut the kill switch and the thing backfired on me! Please guys any help on this? The bike was started cold it was only ran for about 30 secs before everything turned red and started to smoke!

It helps to provide mileage and year of your bike, what if any mods done, recent service, etc for people to give you advice troubleshooting - and your level of familiarity if any with wrenching diy ...

If you know how to remove the sparkplugs and describe their appearance would help too. Maybe.

[NickyNumbers]

agreed on the carbs as thats likely where the issue is but one thing i dot see around here is anyone with a wide band actually checking and knowing for sure what their AFR is.


I guess everyone is guessing theirs is right?

I use a wideband 02 like that when I'm tunning EFI lol.  Might as well add an EGT probe if we're going to get all crazy with it!


In all seriousness though, its not neccesary on this.  You can work without wideband just fine on these simple machines. 



To the OP:  Sounds like a stuck float.  Pull the carbs, takes 30 minutes tops. 

[weedahoe]

I only use a EGT on diesel applications where I turbos are used so they don't get burnt up.

[craigs449]

agreed on the carbs as thats likely where the issue is but one thing i dot see around here is anyone with a wide band actually checking and knowing for sure what their AFR is.


I guess everyone is guessing theirs is right?

I use a wideband 02 like that when I'm tunning EFI lol.  Might as well add an EGT probe if we're going to get all crazy with it!


In all seriousness though, its not neccesary on this.  You can work without wideband just fine on these simple machines. 



To the OP:  Sounds like a stuck float.  Pull the carbs, takes 30 minutes tops.

Are you saying that the float might be stuck closed (I think that's what you mean), not allowing any fuel into the carb-combustion chamber, and therefore creating a super lean condition? 

OP, are both sides of the exhaust headers glowing red hot, or just one side?

[J_Walker]

Well The bike is a 2005 model GS500f with 11k miles on her. I started working with "Small" engines at a local go-kart place as a shop helper. I mostly worked on unclogging the carbs and replacing the pistons. Also sweeping . that was about a year or so ago. that's where I started to love small engine work.

[noiseguy]

some one push his choke to 'off'. 

+1

Check to see if your choke is hanging up.

[noiseguy]

agreed on the carbs as thats likely where the issue is but one thing i dot see around here is anyone with a wide band actually checking and knowing for sure what their AFR is. I guess everyone is guessing theirs is right?

While I agree this is a great way to optimize jetting when making intake/exhaust changes, this guy's doesn't need help tuning his AFR... if the pipes are glowing red the carbs have something spectacularly wrong with them... not just a main jet that's 140 vs 130.

[The Buddha]

Exhaust glowing red = lean. Not rich.
Cool.
Buddha.